Why have female animals evolved such wild genitals?(smithsonianmag.com)
smithsonianmag.com
Why have female animals evolved such wild genitals?
https://www.smithsonianmag.com/science-nature/why-have-female-animals-evolved-such-wild-genitals-180979813/
261 comments
All: I realize the topic contains triggers and the article plays on them, but please contain yourselves.
In terms of evolution through the donation and acceptance of information carrying material, the most bizarre ritual I have witnessed is that of Developa Linuxia:
These creatures are aware of more modern practices and yet they choose to remain in their own evolutionary niche, in part, because they lament the way in which Developa intercourse has been cheapened and corrupted by an unmentionable website named “something”hub.com.
git format-patch --stdout | mail
... | git am
These creatures are aware of more modern practices and yet they choose to remain in their own evolutionary niche, in part, because they lament the way in which Developa intercourse has been cheapened and corrupted by an unmentionable website named “something”hub.com.
And the real miracle of nature is all that is hidden in "dot dot dot". See "Mama Mia" by Abba et al for more information.
Read in the voice of David Attenborough.
Is this a GPT3 post? made zero sense
To explain the joke..
"donation and acceptance of information carrying material" = a high-enough abstraction to cover both sex and development of the Linux Kernel.
"git format-patch --stdout | mail" = creates a patch (a series of commits wrapped neatly) in std-out and then pipes that into the computer's mail client
"... | git am" = the receiver pipes that information into git which then applies the commits
"donation and acceptance of information carrying material" = a high-enough abstraction to cover both sex and development of the Linux Kernel.
"git format-patch --stdout | mail" = creates a patch (a series of commits wrapped neatly) in std-out and then pipes that into the computer's mail client
"... | git am" = the receiver pipes that information into git which then applies the commits
It's a highly geeky joke about the Linux kernel development process, which is quite antiquated.
Which is to its credit, compared to node hell.
There are steps in between, no need to jump from extreme to extreme.
And there's a reason there is no company worth its salt, no matter the scale, that still works by sending patches by email.
And there's a reason there is no company worth its salt, no matter the scale, that still works by sending patches by email.
There's no company that operates at a scale comparable to the Linux kernel and still has a single individual taking the final call about merging code into trunk.
Linux kernel development works perfectly well using mailing lists. The fact that it discourages people who can't bother spending 15 minutes to learn how to send a patch is a feature, not a bug.
Linux kernel development works perfectly well using mailing lists. The fact that it discourages people who can't bother spending 15 minutes to learn how to send a patch is a feature, not a bug.
I'm willing to bet that once the current generation of top level Linux hackers retires, Linux development will be reformed.
Hogwash. Email for the LKML is the equiv of a daily standup, or walking over to someone's desk.
It's pre-commit. A way to work out if it gets into git, or what not.
But of course, if something has worked well for decades, and continues to work well, that's meaningless.
It's pre-commit. A way to work out if it gets into git, or what not.
But of course, if something has worked well for decades, and continues to work well, that's meaningless.
Is it “extreme” because it’s antiquated? If so, how do you distinguish between antiquated-and-bad versus proven-and-robust.
It seems fairly straightforward to me..when it is expensive to procreate due to restricted resources, procreation becomes picky. Birds are mostly monogamous because flying is very energy intensive and the male parent doesn’t want to waste resource on fledglings that isn’t his..obviously, exceptions exist. It is very costly to raise the young. Parental investment is high.
It is different for birds that don’t fly. Water fowl especially have a different reproductive system. Because they don’t fly. This is true for all flightless birds. Even for birds like geese that only fly for seasonal migration. They get their food from the water. Ground dwellers have plenty of food and don’t have spend as much energy foraging for food as a bird that flies. Very few of them mate for life.
Further: Galus Galus has different design than geese and ducks. Castrated roosters are called ‘capons’(French)…produces a nice soft fat capon for Sunday lunch. It’s genitalia is less developed than say..geese.
As a chef, I knew how to sex identify geese/duck. water fowl genitalia is different than fowl. Most farmers know this as sex determination is key to raising animals for profit. With the exception of Pilgrim/Emden/White Italian and some Chinese geese where the autosexing is straightforward with feather colouring and down colour, most have to be identified while they are still goslings.
Goslings can be gender identified as early as the first week and also when they are adults. Male adult penis is invaginated and like a corkscrew. Female organs has genital eminence. The breeding ratio is 1:3 or max 1:5. So it’s important to separate them as early as possible.
Mammals are different..example: feline penii is barbed and most copulation results in kittens. A female cat can have a single litter with multiple tomcats. Male cats will kill kittens ..probably those that aren’t their own..because a lactating mother cat won’t go into heat.
With insects like bees and mantii, the male often meets his end after sex. It comes down to energy needs and availability of resources.
P.S: [..] Birds, she thought at the time, didn’t have penises. In her two years studying them at Cornell University, a world leader in avian research, she’d never once heard her colleagues mention a bird penis.[..] Huh! Really? Cornell university scientists don’t know what a farm child picks up during one farming season? The article is full of red flags for clickbait lies.
It is different for birds that don’t fly. Water fowl especially have a different reproductive system. Because they don’t fly. This is true for all flightless birds. Even for birds like geese that only fly for seasonal migration. They get their food from the water. Ground dwellers have plenty of food and don’t have spend as much energy foraging for food as a bird that flies. Very few of them mate for life.
Further: Galus Galus has different design than geese and ducks. Castrated roosters are called ‘capons’(French)…produces a nice soft fat capon for Sunday lunch. It’s genitalia is less developed than say..geese.
As a chef, I knew how to sex identify geese/duck. water fowl genitalia is different than fowl. Most farmers know this as sex determination is key to raising animals for profit. With the exception of Pilgrim/Emden/White Italian and some Chinese geese where the autosexing is straightforward with feather colouring and down colour, most have to be identified while they are still goslings.
Goslings can be gender identified as early as the first week and also when they are adults. Male adult penis is invaginated and like a corkscrew. Female organs has genital eminence. The breeding ratio is 1:3 or max 1:5. So it’s important to separate them as early as possible.
Mammals are different..example: feline penii is barbed and most copulation results in kittens. A female cat can have a single litter with multiple tomcats. Male cats will kill kittens ..probably those that aren’t their own..because a lactating mother cat won’t go into heat.
With insects like bees and mantii, the male often meets his end after sex. It comes down to energy needs and availability of resources.
P.S: [..] Birds, she thought at the time, didn’t have penises. In her two years studying them at Cornell University, a world leader in avian research, she’d never once heard her colleagues mention a bird penis.[..] Huh! Really? Cornell university scientists don’t know what a farm child picks up during one farming season? The article is full of red flags for clickbait lies.
> Birds are mostly monogamous
This is quite misleading without further context.
My understanding is that a majority of birds are observed to be "socially monogamous"; that is they form a pair lasting a single breeding season, and the pair works together to raise that season's brood. It's only a minority of species in which the same pairs reform across multiple seasons. I don't know how well understood this is; at least for sea birds, which are general among those to form long-term relationships, I've heard a theory that it might be related to the fact that fishing is an aquired skill that should improve with age; finding enough fish to feed both parents and chicks is difficult, and therefore there's a bigger risk if you change partners. The difficulty of finding food, and long time after birth before the offspring become self-sufficient, means these birds can typically only raise one or at most two young per year, so again the cost of failure is high.
Even though in general the rate of social monogamy among bird species is high, this doesn't mean that birds are always parenting their own offspring. In some species (kittiwakes, terns) parenting others' chicks is really rare, but in other species there can be high rates of sexual infidelity e.g. some studies suggest that ~20% of chicks in flycatchers and ~30% in cardinals are unrelated to one (or, less commonly, both) parents. The latter may seem surprising, but of course brood parasitism (e.g. cuckoos) is well known, and there's a same-species variant of that in some species where a female will intentionally lay some eggs in the nest of another pair.
This is quite misleading without further context.
My understanding is that a majority of birds are observed to be "socially monogamous"; that is they form a pair lasting a single breeding season, and the pair works together to raise that season's brood. It's only a minority of species in which the same pairs reform across multiple seasons. I don't know how well understood this is; at least for sea birds, which are general among those to form long-term relationships, I've heard a theory that it might be related to the fact that fishing is an aquired skill that should improve with age; finding enough fish to feed both parents and chicks is difficult, and therefore there's a bigger risk if you change partners. The difficulty of finding food, and long time after birth before the offspring become self-sufficient, means these birds can typically only raise one or at most two young per year, so again the cost of failure is high.
Even though in general the rate of social monogamy among bird species is high, this doesn't mean that birds are always parenting their own offspring. In some species (kittiwakes, terns) parenting others' chicks is really rare, but in other species there can be high rates of sexual infidelity e.g. some studies suggest that ~20% of chicks in flycatchers and ~30% in cardinals are unrelated to one (or, less commonly, both) parents. The latter may seem surprising, but of course brood parasitism (e.g. cuckoos) is well known, and there's a same-species variant of that in some species where a female will intentionally lay some eggs in the nest of another pair.
Yes, indeed. Thanks for explaining. In birds, pair bonding is seasonal. It’s a reproductive strategy to ensure survival of the fledglings.
Of course, there are exceptions here too..there are brood parasites too. Long migrations, short nesting periods .. long incubation time and of course anything that requires courting displays (like the peacock..swans etc) make monogamy a necessary evolutionary strategy.
Some migratory birds return every year to the same spot they roost every year and such memorized cooperative efforts make them staunchly monogamous. I have had the good fortune to witness a pair of nesting ospreys for the past five something years. Nature is wicked smart.
Of course, there are exceptions here too..there are brood parasites too. Long migrations, short nesting periods .. long incubation time and of course anything that requires courting displays (like the peacock..swans etc) make monogamy a necessary evolutionary strategy.
Some migratory birds return every year to the same spot they roost every year and such memorized cooperative efforts make them staunchly monogamous. I have had the good fortune to witness a pair of nesting ospreys for the past five something years. Nature is wicked smart.
I'm a little confused about your statement that waterfowl don't fly.
As far a why a Cornell scientist didn't know about bird penises, it's because the vast majority of bird species don't have them. If she didn't do much work with Anserids, it wouldn't be surprising at all that she hadn't encountered them.
As far a why a Cornell scientist didn't know about bird penises, it's because the vast majority of bird species don't have them. If she didn't do much work with Anserids, it wouldn't be surprising at all that she hadn't encountered them.
For food. They don’t have to fly around for calories. They forage at ground level(ground dwellers) as mentioned in the reply. I mentioned this because most birds have hollow bones and high metabolism. Most birds burn most of the food calories they collect because flying is very energy intensive.
This was about fowl and water fowl penii. That a male duck has a penis is rather well know farmers and chefs and scientists who study about their subjects.
The bird mentioned is a ground dwelling bird (possibly flightless) and every scientist is required to ask WHY. The answer to The Why of fowl and waterfowl having penii is simply because they are ground foragers or aquatic.
I used to cook at an offal restaurant and I have pulled enough pluck to know that human beings will eat anything when they are starving if poor.. or when rich enough to seek culinary adventures.
This was about fowl and water fowl penii. That a male duck has a penis is rather well know farmers and chefs and scientists who study about their subjects.
The bird mentioned is a ground dwelling bird (possibly flightless) and every scientist is required to ask WHY. The answer to The Why of fowl and waterfowl having penii is simply because they are ground foragers or aquatic.
I used to cook at an offal restaurant and I have pulled enough pluck to know that human beings will eat anything when they are starving if poor.. or when rich enough to seek culinary adventures.
Waterfowl do fly from water source to water source. Also, they migrate. Also, their bones are hollow.
I still don't see how penises have anything to do with being flightless. You've decided that since tinamous are fairly terrestrial birds that it must be a terrestrial bird thing, so you've found a way to convince yourself that waterfowl don't fly enough to be considered flying birds and then you shoehorned some theory in there about that causing them to have penises.
Chickens, even the Red Junglefowl that the domestic chicken presumably descended from, are much more terrestrial than ducks and geese. You've worked in restaurants. What kind of penis does a chicken have? You know what else is aquatic and doesn't fly? Penguins! What kind of penis does a penguin have? Loons? They're basically wonky ducks. Pheasants, turkeys, kakapos? They've all got penises, right?
I still don't see how penises have anything to do with being flightless. You've decided that since tinamous are fairly terrestrial birds that it must be a terrestrial bird thing, so you've found a way to convince yourself that waterfowl don't fly enough to be considered flying birds and then you shoehorned some theory in there about that causing them to have penises.
Chickens, even the Red Junglefowl that the domestic chicken presumably descended from, are much more terrestrial than ducks and geese. You've worked in restaurants. What kind of penis does a chicken have? You know what else is aquatic and doesn't fly? Penguins! What kind of penis does a penguin have? Loons? They're basically wonky ducks. Pheasants, turkeys, kakapos? They've all got penises, right?
No. Water fowl bones have higher density than..say..a finch or sparrow. Flying birds have different lung design..they have to be light and smaller birds hearts beat faster than bigger birds. A raptor has a slower heart rate than a hummingbird.
Yes. Waterfowl have hollow bones. They may be denser than a hummingbird's, but that does not mean they are solid.
Raptors have a slower heartbeat than hummingbirds. That is true. What does that have to do with any of this?
Raptors have a slower heartbeat than hummingbirds. That is true. What does that have to do with any of this?
https://www.birdspot.co.uk/bird-reproduction/do-birds-have-p...
[..] In birds, apoptosis of the genital tubercle is triggered by a gene called Bone morphogenetic protein 4, or Bmp4, a protein involved in bone, muscle, cartilage, and limb development. In the majority of birds, Bmp4 gets switched on and blocks the genital tubercle from developing into a penis so they either lack one altogether or it’s so small as to be rendered useless.
In ducks and other birds which grow penises, Bmp4 remains switched off and the genital tubercle develops into a functioning penis.
But although this explains how most birds end up penis-less, it doesn’t explain why. And scientists are still not sure of the answer to that conundrum.
There are several plausible explanations. It could be that the loss of the penis was an unfortunate side-effect of Bmp4 triggering other changes to body parts such as the development of feathers, or the variations in beak size. A bird without a penis carries less weight and therefore would be able to fly more easily, although this theory is unlikely when you consider that fact that ducks make some of the longest migrations of all species of birds. And most flightless birds or birds who fly very little, other than the ratites, have non-existent penises.[..]
Hope this helps.
[..] In birds, apoptosis of the genital tubercle is triggered by a gene called Bone morphogenetic protein 4, or Bmp4, a protein involved in bone, muscle, cartilage, and limb development. In the majority of birds, Bmp4 gets switched on and blocks the genital tubercle from developing into a penis so they either lack one altogether or it’s so small as to be rendered useless.
In ducks and other birds which grow penises, Bmp4 remains switched off and the genital tubercle develops into a functioning penis.
But although this explains how most birds end up penis-less, it doesn’t explain why. And scientists are still not sure of the answer to that conundrum.
There are several plausible explanations. It could be that the loss of the penis was an unfortunate side-effect of Bmp4 triggering other changes to body parts such as the development of feathers, or the variations in beak size. A bird without a penis carries less weight and therefore would be able to fly more easily, although this theory is unlikely when you consider that fact that ducks make some of the longest migrations of all species of birds. And most flightless birds or birds who fly very little, other than the ratites, have non-existent penises.[..]
Hope this helps.
[deleted]
Are you arguing with me for amusement or speaking from authority? I need that clarified before I can spend more time on this.
We can go over entire lists of all the birds found in nature but the way it actually works is we classify them into broad categories and generalize.
We can go over entire lists of all the birds found in nature but the way it actually works is we classify them into broad categories and generalize.
Both. I've got a biology background and have education in ornithology and ecology. I've spent time in the field with a number of species of birds. It's been a while since I've worked with birds, but I've got a solid foundation and am capable of understanding the literature for topics where my memory's lapsed.
Yes, we classify them into categories. I'm trying to figure out how you've managed to convince yourself that ducks and tinamous fall into this special category of terrestrial birds which the experts should obviously know have penises for obvious reasons, but these other birds with the same life history don't fall into this magical category and thus don't have them. What about tinamous and anatids place them in this group which excludes penguins, turkeys, loons, and all of the other birds which are either aquatic or terrestrial and do not have penises?
Edit: I'm also waiting here for you to bring the Rattites into this. I'm a little disappointed honestly. There's some arguments for you to make from that family and I don't know why you haven't brought them up.
Yes, we classify them into categories. I'm trying to figure out how you've managed to convince yourself that ducks and tinamous fall into this special category of terrestrial birds which the experts should obviously know have penises for obvious reasons, but these other birds with the same life history don't fall into this magical category and thus don't have them. What about tinamous and anatids place them in this group which excludes penguins, turkeys, loons, and all of the other birds which are either aquatic or terrestrial and do not have penises?
Edit: I'm also waiting here for you to bring the Rattites into this. I'm a little disappointed honestly. There's some arguments for you to make from that family and I don't know why you haven't brought them up.
I didn’t say tinamous and ducks fall in the same category. I said that it makes sense for ground foragers(most flightless birds) and water fowl(anatids) to be more picky with their mate selection due to the easier access to resources.
Birds copulating in flight are not resisting and simply cannot due to their dynamics.
Where did you get information about loon, penguin and turkeys and their respective penii? They are not adjacent classes as chicken and geese(which was what I was talking about..).
Birds copulating in flight are not resisting and simply cannot due to their dynamics.
Where did you get information about loon, penguin and turkeys and their respective penii? They are not adjacent classes as chicken and geese(which was what I was talking about..).
msrenee(1)
Let’s break it down:
1. Do the birds have easy access to food resources?
2. Do they have to take flight to look for food?
3. Do they migrate?
4. Do they have predators in the wild?
5. Are they aggressive or docile?
6. Are they domesticated?
7. Are they monogamous or promiscuous?
Take all the bird examples you can think of + chicken/eggs.
Make a table and let me know how my ‘shoehorned’ theory fails. Unlike you, I am not an expert. Or a scientist. I farm and have been a chef. I haven’t had an opportunity to check for ostrich penis, but I have cooked them for breakfast.
1. Do the birds have easy access to food resources?
2. Do they have to take flight to look for food?
3. Do they migrate?
4. Do they have predators in the wild?
5. Are they aggressive or docile?
6. Are they domesticated?
7. Are they monogamous or promiscuous?
Take all the bird examples you can think of + chicken/eggs.
Make a table and let me know how my ‘shoehorned’ theory fails. Unlike you, I am not an expert. Or a scientist. I farm and have been a chef. I haven’t had an opportunity to check for ostrich penis, but I have cooked them for breakfast.
How do you explain the fact that penguins, turkeys, and loons do not have penises even though they all fit your requirements for birds that should have them?
What is your opinion as an expert and a biologist?
ETA: I am not interested in an never ending ‘what about’ or gotcha games. However, if you are willing, I will walk you through critical thinking process using logic and multi modal approach to answering questions that confound us.
I will present you with a set of questions you can answer as a biologist/expert or you can google. At the end of it, you will arrive at the answer you want. It will be fun.
ETA: I am not interested in an never ending ‘what about’ or gotcha games. However, if you are willing, I will walk you through critical thinking process using logic and multi modal approach to answering questions that confound us.
I will present you with a set of questions you can answer as a biologist/expert or you can google. At the end of it, you will arrive at the answer you want. It will be fun.
Lmao.
> P.S: [..] Birds, she thought at the time, didn’t have penises. In her two years studying them at Cornell University, a world leader in avian research, she’d never once heard her colleagues mention a bird penis.[..] Huh! Really? Cornell university scientists don’t know what a farm child picks up during one farming season? The article is full of red flags for clickbait lies.
Uh, here in Germany we took until February 2022 to have the first anatomically correct drawing of a human clitoris in a schoolbook [1]. I'm pretty sure the US hasn't reached even that state, given that university textbooks aren't accurate either [2].
And when we can't even manage to have anatomically correct drawings in university textbooks for our own species, how on earth can we assume that the situation is different in veterinary science?!
Farm kids obviously know the difference because they have first-hand experience. But most farm kids don't go and become veterinary scientists or scientists at all!
[1] https://kurier.at/leben/gesellschaft/keine-scham-klitoris-er...
[2]: https://www.vice.com/en/article/nejny8/fear-of-the-clit-a-br...
Uh, here in Germany we took until February 2022 to have the first anatomically correct drawing of a human clitoris in a schoolbook [1]. I'm pretty sure the US hasn't reached even that state, given that university textbooks aren't accurate either [2].
And when we can't even manage to have anatomically correct drawings in university textbooks for our own species, how on earth can we assume that the situation is different in veterinary science?!
Farm kids obviously know the difference because they have first-hand experience. But most farm kids don't go and become veterinary scientists or scientists at all!
[1] https://kurier.at/leben/gesellschaft/keine-scham-klitoris-er...
[2]: https://www.vice.com/en/article/nejny8/fear-of-the-clit-a-br...
But most farm kids don't go and become veterinary scientists or scientists at all!
What the?! Where is your data on this?
Do you think the offspring of farmers are stupid? This seems incredibly biased.
What the?! Where is your data on this?
Do you think the offspring of farmers are stupid? This seems incredibly biased.
To give generous interpretation whenever possible, I am assuming op is talking simple statistics: I.e. "Most of anything don't become veterinary scientists".
Actually, I meant what I said. Rural and urban education outcomes are provably and statistically relevant different [1] - I simply assumed this to be at least somewhat common knowledge or at least intuition.
[1]: https://academic.oup.com/joeg/article/21/5/683/5998980
[1]: https://academic.oup.com/joeg/article/21/5/683/5998980
>But most farm kids don't go and become veterinary scientists or scientists at all!
This statement lives or dies by your definition of 'scientist', but if we're talking about research scientists, it seems trivially obvious that a group constituting a small minority of the population would be quite unlikely to be a majority of 'farm kids'.
Having gotten that out of the way,I agree that it read as deliberately derogatory. Grandparent also draws the specious connection between knowledge and something being present in elementary textbooks, which I found more misleading. Clearly the body of knowledge of a society extends infinitely beyond the contents of their elementary textbooks; even the knowledge of the grade-school user of said book does so.
This statement lives or dies by your definition of 'scientist', but if we're talking about research scientists, it seems trivially obvious that a group constituting a small minority of the population would be quite unlikely to be a majority of 'farm kids'.
Having gotten that out of the way,I agree that it read as deliberately derogatory. Grandparent also draws the specious connection between knowledge and something being present in elementary textbooks, which I found more misleading. Clearly the body of knowledge of a society extends infinitely beyond the contents of their elementary textbooks; even the knowledge of the grade-school user of said book does so.
> What the?! Where is your data on this?
See for example here: https://academic.oup.com/joeg/article/21/5/683/5998980
> Do you think the offspring of farmers are stupid?
No, rather that the education opportunities in rural areas are rather scarce and underfunded (because school funding depends on the number of citizens, which is lower in rural areas), and as a result the education outcomes are worse (see above).
See for example here: https://academic.oup.com/joeg/article/21/5/683/5998980
> Do you think the offspring of farmers are stupid?
No, rather that the education opportunities in rural areas are rather scarce and underfunded (because school funding depends on the number of citizens, which is lower in rural areas), and as a result the education outcomes are worse (see above).
Scientists are what 1% of the population? I doubt even children of scientists mostly become scientists.
And that 1% is further distributed along a competency curve. Substantially less than 100% of scientists are actually good at their job.
Most kids don't go and become scientists – why on earth would saying that specifically about farm kids be biased? Also, isn't farming an occupation where it's more common to inherit it from your parents than for other occupations?
Also, why would not becoming scientists equal to being stupid? Kind of biased, hmm?
Also, why would not becoming scientists equal to being stupid? Kind of biased, hmm?
As described in a parallel comment: Farm kids mostly live in, well, rural areas (okay, there is a small percentage of farms in urban areas too...), which means that the chance of them obtaining higher education is provably lower than the chance that urban-area kids get.
> But most farm kids don't go and become veterinary scientists or scientists at all!
I think the more accurate complaint is most farm kids don't grow up on farms with ducks.
Ducks are pretty niche in the US. If it's not on the menu at McDonald's or Taco Bell, it's not on 95% of US farms.
I think the more accurate complaint is most farm kids don't grow up on farms with ducks.
Ducks are pretty niche in the US. If it's not on the menu at McDonald's or Taco Bell, it's not on 95% of US farms.
World of warcarft, that displays every kind of topography, vegetation, animals, references to any form of pop culture, sports, ... does not contain a single duck.
Either the author have never seen one. Or they are scared of Disney. Hints for the latter might be that there no mice either. For visual completeness there are rats, which is close enough to not need mice.
Either the author have never seen one. Or they are scared of Disney. Hints for the latter might be that there no mice either. For visual completeness there are rats, which is close enough to not need mice.
Now I'm thinking about the last time I saw a duck in a video game or in common culture. The only things I can think of is the game Duck Hunt, and the Oregon ducks. When I think of ducks being eaten, my mind goes to Chinese food or hunters but that's about it.
Minecraft had ducks. Or they were chickens. I remember it being a whole thing, but people called them ducks often enough that I think it should count. As far as ducks being eaten, I've only had duck meat a couple of times, but I'm about to have consistent access to duck eggs and I'm freaking excited.
I know a decent number of people that duckhunt and I've tripped over domestic breeds on friends' acreages often enough. They're easy birdwatching too if you bundle up, so if you hang out with that sort of crowd, you'll hear plenty of discussion. It might just depend on how much time you spend out of the city or staring at ponds.
I know a decent number of people that duckhunt and I've tripped over domestic breeds on friends' acreages often enough. They're easy birdwatching too if you bundle up, so if you hang out with that sort of crowd, you'll hear plenty of discussion. It might just depend on how much time you spend out of the city or staring at ponds.
Red Dead Redemption 2 has several species of ducks that you can hunt https://reddead.fandom.com/wiki/Duck_(RDR_2)
Duck Tales, Donald Duck, duck confit.
Ducks are very common on US farms. Go to any 4H meet.
I grew up on a farm in Indiana, went through 4H, and I've never seen a duck penis, nor heard word of them til the internet got ahold of the news, and Indiana accounts for 45% of US duck production. Which I also didn't know until googling it just now.
I’m not an ornithologist and I already knew about exploding corkscrew duck penises (via Wikipedia) for about half a decade. I also thought it was weird the article wrote it as if a researcher just discovered this information.
Well, the article starts from the year 2000.
I don't know exactly when I first learned about duck penises and labyrinthine duck vaginas, it's not precisely a 9/11 memory, but it was certainly after I left the farm in 2001 and could be entirely due to news reports about this researcher's research trickling out to the pop sci blogosphere.
I don't know exactly when I first learned about duck penises and labyrinthine duck vaginas, it's not precisely a 9/11 memory, but it was certainly after I left the farm in 2001 and could be entirely due to news reports about this researcher's research trickling out to the pop sci blogosphere.
Not shocked at all your sourced Vice.
>Uh, here in Germany we took until February 2022 to have the first anatomically correct drawing of a human clitoris in a schoolbook [1].
Oh, for shame. Back in the '70s a whole bunch of pictures of human (oh, and animal) clitorinks were hidden in a box under my friends dads bed.
Oh, for shame. Back in the '70s a whole bunch of pictures of human (oh, and animal) clitorinks were hidden in a box under my friends dads bed.
Water fowl […] don’t fly.
This is incorrect.
This is incorrect.
Oh wait swans...
I don’t understand how sexing birds isn’t a solved ML problem
Male chicks are destroyed in commercial poultry operations. But today you can sex the eggs in the hatchery within three days of incubation. AI is also trained to identify and segregate. In a lot of ways, yes..it’s a solved problem. Adoption will take time but we will get there. Also true for turkeys and ducks as male turkey poults and female ducklings are also destroyed in commercial hatcheries.
Which technique gives you the sex of an egg after 3 days of incubation? I'm reading on this and I'm seeing methods that get down to a week. It's testing for hormones as well and unless you consider being able to read a test AI, I'd also be interested to hear how that is being utilized.
Spectroscopy identifies nucleus in the red blood cells of the last three days of 21 day incubation period. It can be as early as three days after fertilization. All of this..identifying fertilized eggs, environment management and nutrient for post incubation/pre hatching stage..is automated in modern commercial hatcheries. The sex identifying genetic marker is in the nucleus of the red blood cells. Male chicks can be identified at 910nm band of fluorescence in their haemoglobin.
Your first sentence makes no sense, but it did give me enough keywords to find an actual explanation of the process, so that does clear it up.
I'm aware that the rest of this is automated. I guess I just haven't kept up to date with the last 5 years of chicken sexing technology.
I'm aware that the rest of this is automated. I guess I just haven't kept up to date with the last 5 years of chicken sexing technology.
I am glad you got the answers you needed.
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Maybe it is and humans are just cheaper?
I mean, you kind of have to squeeze them a little to see the genitalia. I guess you could have a human hold the bird over the camera or something to sex it, but it's just as easy to teach that human to tell the difference themselves.
I don't really see how machine learning would improve this process
I don't really see how machine learning would improve this process
If birds can identify their own genders from exterior physical characteristics then that means there are subtle physical clues that can be trained via ML.
Can birds tell a male just-hatched chick from a female? I don't know that I've heard of that in any bird. I guess I don't even know how you could test for that. I can ID a typical mature rooster from across the yard. It's the babies that are hard.
Crap, I can't tell a human baby's gender just from the face. The secondary sex characteristics show up closer to puberty pretty much by definition.
Crap, I can't tell a human baby's gender just from the face. The secondary sex characteristics show up closer to puberty pretty much by definition.
It was also technologically easier to develop sex-link chickens, where the male chicks are one color and the female another.
I assumed your comment was a joke, but after reading the answers I'm not sure anymore
Well I read the word sexting and spit out my coffee.
> It seems fairly straightforward to me..
Your comment has a lot of interesting info, but could’ve easily done without this opening. I don’t see the need to reductively frame your experience against this entire scientific exploration.
Your comment has a lot of interesting info, but could’ve easily done without this opening. I don’t see the need to reductively frame your experience against this entire scientific exploration.
If you don't see the need, does that matter? What's the need for saying this?
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The role of gender in the algorithm of generic selection seems under explored. The males in many species compete to match some criteria of quality observed by females of that species. In some it’s colors, in others voices, boldness, strength, demeanor toward the female, physical competition against other males, the nuance is very rich. But the ability and responsibility to choose the best candidate is core to the female biology. Even down to the egg - the most persistent sperm doesn’t win, but the one approved by the egg with multiple testing criteria at play. In species where the males have evolved to be substantially more physically dominant than the females, you still see defensive mechanisms in the female reproductive organs.
Why has biological gendering evolved to lead to this dynamic? Is it to enable one sex to vary wildly evolutionarily to respond to wildly changing conditions, while the other maintains the stability of the species? Is it because of what we’ve seen in human governments where division of power keeps one dominant bad leader from sinking the whole species? We saw GANs lead to tremendous boosts in creativity in machine learning algorithms. What if we apply these two-role algorithms (competing side and curating side) into machine learning and see where it takes us with agent systems for example? It’s already applied in business [Founders (competing), investors (curating)] and education [students and universities].
Why has biological gendering evolved to lead to this dynamic? Is it to enable one sex to vary wildly evolutionarily to respond to wildly changing conditions, while the other maintains the stability of the species? Is it because of what we’ve seen in human governments where division of power keeps one dominant bad leader from sinking the whole species? We saw GANs lead to tremendous boosts in creativity in machine learning algorithms. What if we apply these two-role algorithms (competing side and curating side) into machine learning and see where it takes us with agent systems for example? It’s already applied in business [Founders (competing), investors (curating)] and education [students and universities].
See Bateman's principle [1]. In most species, variability in reproductive success is greater in males than in females. This is also true for humans (even today) [2], modern human may have twice as many female ancestors as male ancestors.
This is fairly intuitive result when you consider gestation time - imagine a scenario where there are more male than female in a given moment for a given species. At most each female got fertilized once, so the number of distinct male parents is less than or equal to the number of females. If there are more females than males, the you get the same situation (less distinct male parents). This result is simply because a male parent can fertilize multiple females quickly, while gestation period limit the females.
This dynamic has led to sexual selection mostly affecting the males of the species, which means that this is where the competition happens. The move from polygamy to monogamy in human culture has allowed more males to reproduce and reduced this effect (although it still exists, and is significant).
1. https://en.wikipedia.org/wiki/Bateman%27s_principle
2. https://en.wikipedia.org/wiki/Reproductive_success#Humans
This is fairly intuitive result when you consider gestation time - imagine a scenario where there are more male than female in a given moment for a given species. At most each female got fertilized once, so the number of distinct male parents is less than or equal to the number of females. If there are more females than males, the you get the same situation (less distinct male parents). This result is simply because a male parent can fertilize multiple females quickly, while gestation period limit the females.
This dynamic has led to sexual selection mostly affecting the males of the species, which means that this is where the competition happens. The move from polygamy to monogamy in human culture has allowed more males to reproduce and reduced this effect (although it still exists, and is significant).
1. https://en.wikipedia.org/wiki/Bateman%27s_principle
2. https://en.wikipedia.org/wiki/Reproductive_success#Humans
Can we look at species like Betta fish (I believe here the males do the hatching) to confirm such hypotheses?
For typical oviparous fish the cost and timing of reproduction is similar between males and females (dumping a large mass of sperm vs. dumping a large mass of eggs, then taking care of the children) and fancy reproductive organs are irrelevant technology.
Exactly, however, the parent post also tried to expand this to a more general concept of evolutionary pressure and competitive behavioural patterns as I understood. If that is true we can solve a lot of 'problems' in the world by simply having the men doing at least most of the child care for the first few month of a toddlers life to compensate for the for the month before.
> modern human may have twice as many female ancestors as male ancestors.
I'm having trouble to understand how this can be true. It seems like every human should have equal numbers of male and female ancestors, e.g. by induction on how many generations back you look.
I'm having trouble to understand how this can be true. It seems like every human should have equal numbers of male and female ancestors, e.g. by induction on how many generations back you look.
A single man can be your ancestor in more than one slot on your family tree.
Yes, but this is pretty severely understated. Everyone in your family tree definitely will appear there many times over, except for very recent ancestors.
Taking an average human generation time of 25 years, you would theoretically have 2^30 = roughly a billion ancestors 30 generations back, or 750 years ago. But the population of the Earth in 1300 was... maybe 400 million. (e.g. https://www.census.gov/data/tables/time-series/demo/internat... for world population estimates)
And your ancestors in 1300 aren't drawn from the entire population of the world; they're drawn from a tightly restricted subset of that.
And if you think that's ridiculous, imagine how many ancestors you'd have thirty-one generations back!
Taking an average human generation time of 25 years, you would theoretically have 2^30 = roughly a billion ancestors 30 generations back, or 750 years ago. But the population of the Earth in 1300 was... maybe 400 million. (e.g. https://www.census.gov/data/tables/time-series/demo/internat... for world population estimates)
And your ancestors in 1300 aren't drawn from the entire population of the world; they're drawn from a tightly restricted subset of that.
And if you think that's ridiculous, imagine how many ancestors you'd have thirty-one generations back!
everyone has more single uncles than single aunts. Human history was not entirely monogamous, and a few number of men mated a larger number of women.
Interestingly, there is this paragraph in the Wikipedia article:
> Although Bateman's principle served as a cornerstone for the study of sexual selection for many decades, it has recently been subject to criticism. Attempts to reproduce Bateman's experiments in 2012 and 2013 were unable to support his conclusions. Some scientists have criticized Bateman's experimental and statistical methods, or pointed out conflicting evidence, while others have defended the veracity of the principle and cited evidence in support of it.
Seems like a very convincing conjecture otherwise, though.
> Although Bateman's principle served as a cornerstone for the study of sexual selection for many decades, it has recently been subject to criticism. Attempts to reproduce Bateman's experiments in 2012 and 2013 were unable to support his conclusions. Some scientists have criticized Bateman's experimental and statistical methods, or pointed out conflicting evidence, while others have defended the veracity of the principle and cited evidence in support of it.
Seems like a very convincing conjecture otherwise, though.
The main difference between male and female is cost of reproduction. Sperm is tiny and can be produced in massive quantities. Eggs are much larger and take more energy to produce. This difference is then carried into other parts of reproductive strategy. The two sexes reach a state of equilibrium with each other in terms of strategy.
Females are super careful about picking a mate because they spend months making an egg. They have a sunk cost. And females are relatively more caring about young because it is cheaper than making a new egg.
This access control forces males to evolve to be pleasing and provide some proof of quality. And this proof of quality can create more of a sunk cost for the male. They stick around and protect the young because it is easier to do that than find another female, impress them, build a nest etc.
Also, sex is very very obvious in terms of primary sexual characteristics. We have literally evolved to focus on those things. But outside of reproduction it is far less obvious in biology. On an individual level it is better to think of sex as an output rather than an input. Things don't happen because of the sex variables state, rather sexual characteristics are a consequence of other processes.
Females are super careful about picking a mate because they spend months making an egg. They have a sunk cost. And females are relatively more caring about young because it is cheaper than making a new egg.
This access control forces males to evolve to be pleasing and provide some proof of quality. And this proof of quality can create more of a sunk cost for the male. They stick around and protect the young because it is easier to do that than find another female, impress them, build a nest etc.
Also, sex is very very obvious in terms of primary sexual characteristics. We have literally evolved to focus on those things. But outside of reproduction it is far less obvious in biology. On an individual level it is better to think of sex as an output rather than an input. Things don't happen because of the sex variables state, rather sexual characteristics are a consequence of other processes.
> Eggs are much larger and take more energy to produce.
>Females are super careful about picking a mate because they spend months making an egg.
The prevailing science was that females - assuming we are talking about humans - don’t make eggs rather are born with a finite number that reduces over their life time.
Only in the last couple years has the science begun to be questioned with the possibility that women do in fact make new eggs during adulthood. However, as far as I know that is still an open ended question being studied, whereas you offer some very specific facts about the required energy to produce eggs, which would suggest that in fact studies have not only confirmed women do actually make new eggs during their lifetime but there is further understanding about that process.
Could you link any studies about women producing new eggs “every couple months” and the energy required that you reference?
>Females are super careful about picking a mate because they spend months making an egg.
The prevailing science was that females - assuming we are talking about humans - don’t make eggs rather are born with a finite number that reduces over their life time.
Only in the last couple years has the science begun to be questioned with the possibility that women do in fact make new eggs during adulthood. However, as far as I know that is still an open ended question being studied, whereas you offer some very specific facts about the required energy to produce eggs, which would suggest that in fact studies have not only confirmed women do actually make new eggs during their lifetime but there is further understanding about that process.
Could you link any studies about women producing new eggs “every couple months” and the energy required that you reference?
It is a higher cost regardless of when that cost is incurred. Although with humans I would guess that the 9 months of pregnancy and years of care is the relevant sunk cost. Compare that to the relative ease of a male who could have many offspring per year with little effort.
> Although with humans I would guess that the 9 months of pregnancy and years of care is the relevant sunk cost.
Humans are social animals with a wide variety of cultural values, in most cultures throughout history it won’t be a viable option for a man to go around impregnating multiple women every year and likely result in becoming a social outcast in civilized societies or outright killed in others.
Most cultures tend to be monogamous, courting and marriage being fairly common and also dowries were and are real thing -where a man pays a cost for each daughter to be married - not to mention co-evolution of societal norms that have also resulted in laws in some societies requiring child support until a child is 18. Whatever the natural biological costs, humans seem to have created different social norms and laws that have there own costs tending to curb the behavior you describe.
Humans are social animals with a wide variety of cultural values, in most cultures throughout history it won’t be a viable option for a man to go around impregnating multiple women every year and likely result in becoming a social outcast in civilized societies or outright killed in others.
Most cultures tend to be monogamous, courting and marriage being fairly common and also dowries were and are real thing -where a man pays a cost for each daughter to be married - not to mention co-evolution of societal norms that have also resulted in laws in some societies requiring child support until a child is 18. Whatever the natural biological costs, humans seem to have created different social norms and laws that have there own costs tending to curb the behavior you describe.
But that behaviour (monogamous, courting and marriage) can absolutely be seen as an evolutionary adaption. Male birds do not really need to help a female build a nest or look after eggs. But if they don't the female will deny access to sex, or the offspring will never hatch. And the female could just mate with any random bird, and not bother building a nest. But the egg won't survive.
The same is true of humans. If a males want their kids to survive to reproductive age then looking after their mum and the kids during infancy is the best strategy. And the best strategy for the mum is to use what power she has to encourage that. That may not be entirely a reflection of biology now, but it certainly was in the past. And it is no accident that humans find certain traits attractive in a mate.
But the difference in cost absolutely does still exist. Single parent households where the mum is left holding the baby are not exactly unusual. And the health burden of carrying a child and birthing is 100% on the women.
The same is true of humans. If a males want their kids to survive to reproductive age then looking after their mum and the kids during infancy is the best strategy. And the best strategy for the mum is to use what power she has to encourage that. That may not be entirely a reflection of biology now, but it certainly was in the past. And it is no accident that humans find certain traits attractive in a mate.
But the difference in cost absolutely does still exist. Single parent households where the mum is left holding the baby are not exactly unusual. And the health burden of carrying a child and birthing is 100% on the women.
> Only in the last couple years has the science begun to be questioned with the possibility that women do in fact make new eggs during adulthood. However, as far as I know that is still an open ended question being studied,
Of all things we know and think we know, we still don't know this? That's a miracle.
Of all things we know and think we know, we still don't know this? That's a miracle.
I think they were referring to gestation, rather than the initial production of the ovule.
The cost of an egg is negligible compared to the cost of gestation, ie. bringing the embryo all the way to a baby.
Sexuality is a solution to Muller's ratchet [0].
[0] https://thehighbook.netlify.app/muller's-ratchet (first half)
[0] https://thehighbook.netlify.app/muller's-ratchet (first half)
The main point is selection at the level of individual sperm. Sperm are very cheap, but carrying an infant to term is very expensive. It is an absolute requirement to avoid carrying an infant with genetic disorders, to whatever extent possible. So the male creates a million sperm, and the female puts them through an obstacle course. A sperm with genetic defects probably won't even survive in the harsh environment, let alone win the race. So you're guaranteed that the winner of the Fallopian race is at least basically healthy, with basic functioning metabolic machinery and so on.
The metabolic machinery in the sperm is thrown away in favor of that in the egg, that's why mitochondrial RNA is matrilineal.
Even if it's thrown away there's still value in proving its function, as a proxy for general genetic fitness.
You are ascribing a utility optimisation to evolution that doesn't happen. There is an arms race happening on the selection because those who successfully procreate proliferate, and it can be difficult to undo changes. It doesn't matter if it's wasted energy or complications to have egg level defense mechanisms, if this trait evolved once because for whatever reason that selectivness was increasing chances of passing down those genes, absent négative sélection pressure and a viable genetic pathway out it's gonna stay there.
If there's a evo geneticist around, one thing I'm wondering is whether some of these traits might have evolved as a heck from the male side. E.g., if I have mutations that increase selectivness of the females against everyone but me, passing those mutations would bias later generations to select for my gene line. I'm not sure whether this is feasible or likely, but it's an example of evolutionary benefit without any real benefit if possible
If there's a evo geneticist around, one thing I'm wondering is whether some of these traits might have evolved as a heck from the male side. E.g., if I have mutations that increase selectivness of the females against everyone but me, passing those mutations would bias later generations to select for my gene line. I'm not sure whether this is feasible or likely, but it's an example of evolutionary benefit without any real benefit if possible
"Parental investment theory, a term coined by Robert Trivers in 1972, predicts that the sex that invests more in its offspring will be more selective when choosing a mate, and the less-investing sex will have intra-sexual competition for access to mates. This theory has been influential in explaining sex differences in sexual selection and mate preferences, throughout the animal kingdom and in humans."
https://en.wikipedia.org/wiki/Parental_investment
https://en.wikipedia.org/wiki/Parental_investment
I wonder if this changes with access to cheap, effective, and easy to use birth control (for both sexes), plus societal enforcement of males to participate sharing their resources to raising children, at least by garnishing wages.
I know many people, male and female, who would be considered prime mating material opting out of having children because they do not want to spend the resources they would have to to raise children.
I know many people, male and female, who would be considered prime mating material opting out of having children because they do not want to spend the resources they would have to to raise children.
I think it has to be all completely historical. In some species the male is the suitor, in others, the female is; and there are - or used to be, sadly - enough species for every linear combination of both possibilities.
If I know anything about nature, it's that it's a brute-force optimizer for biological fitness. Every possible combination of traits could feasibly be tested on these scales.
If I know anything about nature, it's that it's a brute-force optimizer for biological fitness. Every possible combination of traits could feasibly be tested on these scales.
I don't think dzink's point relies on whether the suitor is male or female, but that the distinction exists at all and is so widespread.
> [...] and there are - or used to be, sadly - enough species for every linear combination of both possibilities.
Extinction is sad, but there's still plenty enough species to make this statement true.
> If I know anything about nature, it's that it's a brute-force optimizer for biological fitness. Every possible combination of traits could feasibly be tested on these scales.
Not quite. Eg there's basically no wheel in nature, despite the structure itself being quite simple. That's mostly because it's hard to evolve in small steps.
> [...] and there are - or used to be, sadly - enough species for every linear combination of both possibilities.
Extinction is sad, but there's still plenty enough species to make this statement true.
> If I know anything about nature, it's that it's a brute-force optimizer for biological fitness. Every possible combination of traits could feasibly be tested on these scales.
Not quite. Eg there's basically no wheel in nature, despite the structure itself being quite simple. That's mostly because it's hard to evolve in small steps.
> there's basically no wheel in nature
Agreed, but V-ATPase is worth mentioning as it has a rotor and is very highly conserved. I guess it all depends on scale.
Agreed, but V-ATPase is worth mentioning as it has a rotor and is very highly conserved. I guess it all depends on scale.
Yes. I was talking about a macroscopic wheel.
>male or female, but that the distinction exists at all and is so widespread.
Fair enough. I do find it interesting that even in plants that have N different sexes, their life cycles are still often dimorphic.
Maybe the most fundamental abstraction really is the difference between a 1 and a 0.
Fair enough. I do find it interesting that even in plants that have N different sexes, their life cycles are still often dimorphic.
Maybe the most fundamental abstraction really is the difference between a 1 and a 0.
There is also the third gender in domesticated animals: human breeders. Humans breeders are curating the species and easing the growth of human-favored varieties. There is also the interesting consequences of that in human-disfavored species who evolve to survive in distributed ways despite, or even possibly using our intelligence and tactics in their favor (cockroaches, rodents, viruses, parasites, kudzu, you name it). Nature is a massive calculator, and its algorithms are so interesting, we’ve got to test more of them in computing.
Also have a look at rye and oats. They are both thought to be the result of Vavilovian mimicry.
> In plant biology, Vavilovian mimicry (also crop mimicry or weed mimicry[1][a]) is a form of mimicry in plants where a weed evolves to share one or more characteristics with a domesticated plant through generations of artificial selection.[2] It is named after Nikolai Vavilov, a prominent Russian plant geneticist.[2] Selection against the weed may occur by killing a young or adult weed, separating its seeds from those of the crop (winnowing), or both. This has been done manually since Neolithic times, and in more recent years by agricultural machinery.
> Vavilovian mimicry is a good illustration of unintentional selection by humans. Although the human selective agents might be conscious of their impact on the local weed gene pool, such effects go against the goals of those growing crops. Weeders do not want to select for weeds that are increasingly similar to the cultivated plant, yet the only other option is to let the weeds grow and compete with crops for sunlight and nutrients. Similar situations include antibiotic resistance and, also in agricultural crops, herbicide resistance. Having acquired many desirable qualities by being subjected to similar selective pressures, Vavilovian mimics may eventually be domesticated themselves. Vavilov called these weeds-become-crops secondary crops.
From https://en.wikipedia.org/wiki/Vavilovian_mimicry
> In plant biology, Vavilovian mimicry (also crop mimicry or weed mimicry[1][a]) is a form of mimicry in plants where a weed evolves to share one or more characteristics with a domesticated plant through generations of artificial selection.[2] It is named after Nikolai Vavilov, a prominent Russian plant geneticist.[2] Selection against the weed may occur by killing a young or adult weed, separating its seeds from those of the crop (winnowing), or both. This has been done manually since Neolithic times, and in more recent years by agricultural machinery.
> Vavilovian mimicry is a good illustration of unintentional selection by humans. Although the human selective agents might be conscious of their impact on the local weed gene pool, such effects go against the goals of those growing crops. Weeders do not want to select for weeds that are increasingly similar to the cultivated plant, yet the only other option is to let the weeds grow and compete with crops for sunlight and nutrients. Similar situations include antibiotic resistance and, also in agricultural crops, herbicide resistance. Having acquired many desirable qualities by being subjected to similar selective pressures, Vavilovian mimics may eventually be domesticated themselves. Vavilov called these weeds-become-crops secondary crops.
From https://en.wikipedia.org/wiki/Vavilovian_mimicry
>There is also the interesting consequences of that in human-disfavored species who evolve to survive in distributed ways despite, or even possibly using our intelligence and tactics in their favor (cockroaches, rodents, viruses, parasites, kudzu, you name it).
Nature and nurture. Gattica-level eugenics, at the end of the day, only affect the DNA. And eugenics will never save someone from the adage "Hard times make strong men. Strong men make good times. Good times make weak men. Weak men make hard times."
Nature and nurture. Gattica-level eugenics, at the end of the day, only affect the DNA. And eugenics will never save someone from the adage "Hard times make strong men. Strong men make good times. Good times make weak men. Weak men make hard times."
Not sure that adage is any true?
Eg western militaries don't seem to be worse at fighting than militaries from poor countries?
Eg western militaries don't seem to be worse at fighting than militaries from poor countries?
> The males in many species compete to match some criteria of quality observed by females of that species.
It works in the other direction as well, especially if competition involves expending many resources on a single female. Only attractive females attract many competitors.
> It’s already applied in business [Founders (competing), investors (curating)] [...]
Wouldn't the even more basic dynamic in business been between company and customers? (And of course also between company and suppliers including workers who supply labour (or investors who supply capital, as you mention)?)
It works in the other direction as well, especially if competition involves expending many resources on a single female. Only attractive females attract many competitors.
> It’s already applied in business [Founders (competing), investors (curating)] [...]
Wouldn't the even more basic dynamic in business been between company and customers? (And of course also between company and suppliers including workers who supply labour (or investors who supply capital, as you mention)?)
It's interesting that you bring up the egg. It reminds me of one day in my cell biology class in undergrad when we talked about why there are even eggs and sperm at all. I remember it only vaguely but I think maybe it was something about how small differences in motility and mitochondrial count between similarly shaped and sized cells would put selective pressure on them to differentiate. Maybe it's just a useless thing I don't really remember, but there's a part of my brain that wonders if it would yield some insight into what you're describing.
Sexual divergence is a game theoretical consequence of the differing costs two parents might have to form an offspring via sexual reproduction. Suppose a population of hermaphoditic sexually-reproducing species grows large enough to be comfortably self-sustaining and there is no difficulty in finding / exchanging gametes a sexual partner. At this point, every individual is equally capable of mothering or fathering the offspring, but one (say, mothering) ends up being more expensive because it requires more resource investment. Then a genetic quirk that causes a particular individual to preferentially spend more time fathering will be beneficial towards individual fitness, as the offspring/cost ratio is skewed in their favor. Eventually, one or more such genes catch on, and form the first steps of the evolution of the subpopulation with them into a male-type. And, over time, those better at specializing in being male-type will outcompete those who are less specialists at finding mothering partners, increasingly diverging this subpopulation towards maleness.
Now a population of mixed male-type and hermaphoditic-type individuals by definition can only skew male-type (in the sense that the average individual over the entire population somewhat prefers fathering over mothering). But each offspring has one male and one female parent; i.e. the population of parents does not skew in either direction. Run the math and you'll find that, counting hermaphodites as 1/2 in each category, there are more offspring per female-type than per male-type: those hermaphodites who prefer mothering are now the sexually fittest individuals in the group. And much like in the case with males above, a genetic preference towards mothering will catch on among the hermaphoditic population and begin skewing a subpopulation ever more female-like.
Eventually the male-type and female-type sexes fully diverge from each other, and the initial population of hermaphodites get out competed by the sexual specialists and fall solely into the fossil record.
Now a population of mixed male-type and hermaphoditic-type individuals by definition can only skew male-type (in the sense that the average individual over the entire population somewhat prefers fathering over mothering). But each offspring has one male and one female parent; i.e. the population of parents does not skew in either direction. Run the math and you'll find that, counting hermaphodites as 1/2 in each category, there are more offspring per female-type than per male-type: those hermaphodites who prefer mothering are now the sexually fittest individuals in the group. And much like in the case with males above, a genetic preference towards mothering will catch on among the hermaphoditic population and begin skewing a subpopulation ever more female-like.
Eventually the male-type and female-type sexes fully diverge from each other, and the initial population of hermaphodites get out competed by the sexual specialists and fall solely into the fossil record.
Structurally speaking, it's easy to imagine a number of ways the female could have complete control over the process.
But if we don't observe that complete control (at least not in most species), and instead it's more of an "arms race"; then it makes me think complete control is an evolutionary disadvantage. Is that true?
But if we don't observe that complete control (at least not in most species), and instead it's more of an "arms race"; then it makes me think complete control is an evolutionary disadvantage. Is that true?
I would guess it’s about genetic variety.
If a female duck had complete control, genetic variety would likely decrease quickly as fewer, genetically similar males fathered all the children. This group of ducks would be more susceptible to disease, genetic defects, etc.
It could also be the case that if male ducks can’t be certain who the father is, they are more likely to help protect/not kill the young.
If a female duck had complete control, genetic variety would likely decrease quickly as fewer, genetically similar males fathered all the children. This group of ducks would be more susceptible to disease, genetic defects, etc.
It could also be the case that if male ducks can’t be certain who the father is, they are more likely to help protect/not kill the young.
One thing to keep in mind is that evolution does not produce global optimums - only local ones.
That's kind of a hard thing to measure against, can you tell me of an example in real life where you know something is the global optimum?
You don't need to know something is a global optimum - you just need to know there's a slightly better at-least-local optimum with a decrease in fitness between that and where one is now.
That’s basically why it does local optima rather than global.
As for an example where you know the global optima: real life hill climbing rather than the blindfolded version used to explain the algorithm of the same name?
As for an example where you know the global optima: real life hill climbing rather than the blindfolded version used to explain the algorithm of the same name?
While the individual interactions between organisms are indeed local, sexual evolution precisely attempts to work around this limitation with selection pressure for diversity.
That is to say, sexual evolution increasingly approximates a globally optimal process, as an aggregate system of autonomous agents.
The Internet is also not actually a global network. It's just lots of local connections between two computers. Yet the effect approaches a global network.
That is to say, sexual evolution increasingly approximates a globally optimal process, as an aggregate system of autonomous agents.
The Internet is also not actually a global network. It's just lots of local connections between two computers. Yet the effect approaches a global network.
You use a lot of jargon, but I’m not sure where you ended up.
It seems obvious to me (from logic and observation) that most animals don’t have global connectivity (despite your comparison to internet meshes), and obviously evolve differently across the world.
It seems obvious to me (from logic and observation) that most animals don’t have global connectivity (despite your comparison to internet meshes), and obviously evolve differently across the world.
There is genetic exchange between different animals from across the world, which is a mechanism that has evolved presumably specifically because it strengthens global resolve. It's entirely non-obvious but genetic material propagates through many pathways, including but not limited to sexual reproduction.
Virii, for example, transfer genes between species. Bacteria have plasmids, rings of genes they can literally just give to other bacteria.
Virii, for example, transfer genes between species. Bacteria have plasmids, rings of genes they can literally just give to other bacteria.
I think at some point other limitations come into play that prevent it being an arms race. It would be quite funny, but unfeasible, for most of the male's physical development to go to their reproductive organs. At some point it would weigh you down, you wouldn't be able run fast and you'd get eaten...
> Structurally speaking, it's easy to imagine a number of ways the female could have complete control over the process.
Would you care to name a few?
I don’t immediately see it, unless we assume that the male genitalia stops adapting to whatever the female has.
Would you care to name a few?
I don’t immediately see it, unless we assume that the male genitalia stops adapting to whatever the female has.
There are millipedes that don't have sex. Presumably the female has the ability to curl up inside her armor and there's not much the male can do if that happens. Mating takes place in much the same way most fish do it, with the female releasing eggs and the male fertilizing them. Female fish can't really establish control of the process this way, but female millipedes basically can as long as they only meet one male at a time.
The strategy is not fundamentally stable; female bedbugs have no genitalia at all but that doesn't give them any control.
The strategy is not fundamentally stable; female bedbugs have no genitalia at all but that doesn't give them any control.
> it makes me think complete control is an evolutionary disadvantage
Have you considered that every specie approaches this differently for their own situations? That doesn’t mean it’s a conceptual failure.
Have you considered that every specie approaches this differently for their own situations? That doesn’t mean it’s a conceptual failure.
There's got to be clear advantage, or at least no strong disadvantage across the morphological choices they are constrained to, in the forms. Isabella Rossolini aside, there's no dance here which is pure beauty, its form-follows-function all the way.
Ducks are savage. York University where I studied, in the 70s had a huge shallow lake and it had a regrettable sexual population imbalance which caused fatalities. Randy drakes drowned the decreasing number of ducks. I think they had to do culling to fix it. You think nature would right itself, but in human time for small local populations sometimes it doesn't do a good job.
Ducks are savage. York University where I studied, in the 70s had a huge shallow lake and it had a regrettable sexual population imbalance which caused fatalities. Randy drakes drowned the decreasing number of ducks. I think they had to do culling to fix it. You think nature would right itself, but in human time for small local populations sometimes it doesn't do a good job.
Letting a part of the population die, perhaps entire species or groups of species, is one of the way nature "rights itself".
Describing a species wiping itself out as “nature righting itself” seems to me a bit like saying a shotgun is a cure for cancer.
Why is that not accurate? Nature is just physical processes. Those physical processes taking their course is really all nature does. You could call it “righting itself” or “destroying itself” and I’d say you’re equally right, because the same physical process occurs without moral judgement, and your connotation is just you applying your human morality to the situation
In a mechanical system, say a bicycle, “righting itself” implies returning to an upright position rather than any transition to a stable state — a bike lying horizontal on the ground is in a stable state, but falling over isn’t physics righting itself.
Well, the fatalities were exactly how nature 'righted itself'. Nature ain't squeamish.
The fatalities were a vicious spiral. The males were killing more females, deepening the imbalance.
Which means the next generation would be even smaller and so on and so forth until at one point the thing is reduced to a point where it is no longer sustaining the spiral.
Or at least that's how I imagine it would go.
Or at least that's how I imagine it would go.
Well, let's just say extinction is not the first definition of "nature righting itself" that comes to mind for this scenario.
For better or worse, that point might be a population of zero.
> You think nature would right itself
Why think this? Populations and their environments constitute complex systems, not magical ones. They can self-correct, or not, just like how humans don't always manage to not develop cancer.
Why think this? Populations and their environments constitute complex systems, not magical ones. They can self-correct, or not, just like how humans don't always manage to not develop cancer.
It may help to consider that, while an egg is a chicken's way of making another chicken, equally valid you may view that a chicken is an egg's way of making another egg.
Follow this train of thought, we can imagine that reproductive morphology is there for it's own sake. The genes that create it, are successful if they create creatures that propagate those genes. Never mind how onerous it is to the creature. Sure, they can't cause the creature to actually expire in the effort. But short of that, they can get as strange as galapagos birds and so on, purely for their own sake.
Follow this train of thought, we can imagine that reproductive morphology is there for it's own sake. The genes that create it, are successful if they create creatures that propagate those genes. Never mind how onerous it is to the creature. Sure, they can't cause the creature to actually expire in the effort. But short of that, they can get as strange as galapagos birds and so on, purely for their own sake.
I do wonder how "normal" human genitalia is compared to the vast majority of the animal kingdom. Though is that simply anthrocentric?
The paper you are looking for is http://artemis.austincollege.edu/acad/bio/sgoldsmith/abpdfs/...
Many placental mammals, including the other great apes, have a baculum, while humans do not. I'm not even sure how to start comparing human genitalia to those of jellyfish or tubular worms, to be honest. The animal kingdom is quite broad.
Probably worthwhile to consider it as familiarity bias -- as claimed by the article, the male researchers missed the vaginal shapes, so it's not just anthropocentricism.
I've heard humans have larger penises in proportion to our size than usual with mammals. Not sure how unique it is but the human glans is speculated to be shaped like it is to scoop out sperm from competing males. Since human vaginas aren't "wild" like that of a goose, maybe that is how we have evolved to handle competition? This must go far back though, way before we became humans...
Well, that’s a disturbing and quite gross image.
Insect “penises” vary hugely, or even wilder variations e.g. detachable.
“Insect genitalia have been the focus of much attention since the middle of the 19th century, when their taxonomic value to diagnose species with otherwise very similar [shapes] was recognised.”, “The structure of the female genitalia of Limnebius is poorly known, mostly due to the lack of sclerotized parts”. https://peerj.com/articles/1882/
“Insect genitalia have been the focus of much attention since the middle of the 19th century, when their taxonomic value to diagnose species with otherwise very similar [shapes] was recognised.”, “The structure of the female genitalia of Limnebius is poorly known, mostly due to the lack of sclerotized parts”. https://peerj.com/articles/1882/
Incidentally, my favourite Wikipedia article is the one about the Drone Bee and his dick:
https://en.wikipedia.org/wiki/Drone_(bee)#Mating_and_the_dro...
"Mating between a single drone and the queen lasts less than 5 seconds, and it is often completed within 1–2 seconds. Mating occurs mid-flight, and 10–40 m above ground. Since the queen mates with 5– 19 drones, and drones die after mating, each drone must make the most of his single shot. The drone makes first contact from above the queen, his thorax above her abdomen, straddling her. He then grasps her with all six legs, and everts the endophallus into her opened sting chamber. If the queen’s sting chamber is not fully opened, mating is unsuccessful, so some males that mount the queen do not transfer semen. Once the endophallus has been everted, the drone is paralyzed, flipping backwards as he ejaculates. The process of ejaculation is explosive—semen is blasted through the queen’s sting chamber and into the oviduct. The process is sometimes audible to the human ear, akin to a "popping" sound. The ejaculation is so powerful that it ruptures the endophallus, disconnecting the drone from the queen."
https://en.wikipedia.org/wiki/Drone_(bee)#Mating_and_the_dro...
"Mating between a single drone and the queen lasts less than 5 seconds, and it is often completed within 1–2 seconds. Mating occurs mid-flight, and 10–40 m above ground. Since the queen mates with 5– 19 drones, and drones die after mating, each drone must make the most of his single shot. The drone makes first contact from above the queen, his thorax above her abdomen, straddling her. He then grasps her with all six legs, and everts the endophallus into her opened sting chamber. If the queen’s sting chamber is not fully opened, mating is unsuccessful, so some males that mount the queen do not transfer semen. Once the endophallus has been everted, the drone is paralyzed, flipping backwards as he ejaculates. The process of ejaculation is explosive—semen is blasted through the queen’s sting chamber and into the oviduct. The process is sometimes audible to the human ear, akin to a "popping" sound. The ejaculation is so powerful that it ruptures the endophallus, disconnecting the drone from the queen."
If I could straight up detach my genitals when I didn't need them I'd be golden.
There's a song about that which was popular in the early 90s.
https://en.m.wikipedia.org/wiki/Detachable_Penis
https://en.m.wikipedia.org/wiki/Detachable_Penis
Fascinating article. I'd heard about ducks before, but the complexity is really telling.
I'm not sure I fully appreciate the evolutionary pressure in the bird's "arms" race, in that the female duck chooses mate despite violent competing males. Up to 40% die in the violence -- would that not put evolutionary selection in favor of females that lack resistance?
I'm not sure I fully appreciate the evolutionary pressure in the bird's "arms" race, in that the female duck chooses mate despite violent competing males. Up to 40% die in the violence -- would that not put evolutionary selection in favor of females that lack resistance?
The article said up to 40% of matings were forced, not that 40% of female ducks die from forced matings.
Fair. But even a non-trivial amount dying from forced mating would push evolutionary pressure, right?
I think there is an independent pressure towards aggression and physical size, considering the violence inherent in the animal world.
So you get multidimensional optimization of a single quantity - become too aggressive and your sperm won't pass, but if you're not aggressive enough you might not eat.
So you get multidimensional optimization of a single quantity - become too aggressive and your sperm won't pass, but if you're not aggressive enough you might not eat.
Hey that's a really good point. Thanks!
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I just did a ctrl+F and the article doesn't mention ducks dying at all.
> This often leads to a violent struggle, in which males injure or even drown the female. In some species, up to 40 percent of all matings are forced.
There is no indication of the rate of drowning, but it would be a constant risk across all females, so no real evolutionary pressure would be evident (aside from a risk to the species as a whole). That is to say: the rate of drowning for females would have to be very low, otherwise the species would fail. If the rate was too high, you’d expect to see a counter pressure to have a higher rate of females born versus males.
The point here is that as reproductive structures evolved, the female developed equally complex structures. She might not a choice in if mating occurs, but she does have a choice in whether a particular male fertilizes her eggs. That is the evolutionary pressure… not in response to death from forced mating.
> Whatever the females were doing, they were succeeding. In ducks, only 2 to 5 percent of offspring are the result of forced encounters.
So regardless of if the mating was forced or not, female ducks are quite successful in choosing who fertilizes her eggs.
There is no indication of the rate of drowning, but it would be a constant risk across all females, so no real evolutionary pressure would be evident (aside from a risk to the species as a whole). That is to say: the rate of drowning for females would have to be very low, otherwise the species would fail. If the rate was too high, you’d expect to see a counter pressure to have a higher rate of females born versus males.
The point here is that as reproductive structures evolved, the female developed equally complex structures. She might not a choice in if mating occurs, but she does have a choice in whether a particular male fertilizes her eggs. That is the evolutionary pressure… not in response to death from forced mating.
> Whatever the females were doing, they were succeeding. In ducks, only 2 to 5 percent of offspring are the result of forced encounters.
So regardless of if the mating was forced or not, female ducks are quite successful in choosing who fertilizes her eggs.
Why would it be a constant risk across all females?
There would be quite a lot of pressure to not die from forced mating. Can't reproduce when you are dead after all.
There would be quite a lot of pressure to not die from forced mating. Can't reproduce when you are dead after all.
Split the population of all female ducks into two groups: those that can control the genes passed on to their offspring and those who can’t. From the female perspective, this is the question. Which group will be more successful?
The risk of drowning during mating is the same for both groups. So, neither group gets a natural selection advantage from being less likely to drown, because it is a constant risk for both groups.
The key here is that the males don’t know if the successfully mated with the female (passed on their genes) or not. Only the female knows.
The risk of drowning during mating is the same for both groups. So, neither group gets a natural selection advantage from being less likely to drown, because it is a constant risk for both groups.
The key here is that the males don’t know if the successfully mated with the female (passed on their genes) or not. Only the female knows.
I think their point was that there is no selective pressure on the males to reduce their level of mating violence. From the males' perspective, the situation looks like a prisoners dilemma.
Wouldn't there be lots and lots of pressure?
A male that kills his mate has fewer offspring than a mate that manages to keep the female alive, doesn't he?
A male that kills his mate has fewer offspring than a mate that manages to keep the female alive, doesn't he?
I'm not understanding the selection here - for this to evolve there must be something better about offspring where the female picks the encounter.
Seems to be the strongest evolutionary signal would be where the female has lots of offspring, whether desired or not.
Seems to be the strongest evolutionary signal would be where the female has lots of offspring, whether desired or not.
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>In some cases, the female genital tract prevented the penis from fully inflating, and was full of pockets where sperm went to die.
I think this is what they mean. Not offspring dying per se, but still an evolutionary pressure
I think this is what they mean. Not offspring dying per se, but still an evolutionary pressure
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"Today, we know that genitalia do far more than just fit together mechanically. They can also signal, symbolize and titillate—not just to a potential mate, but to other members of a group. In humans, dolphins and beyond, sexual behavior can be used to strengthen friendships and alliances, make gestures of dominance and submission, and as part of social negotiations like reconciliation and peacemaking, points out evolutionary biologist Joan Roughgarden, author of the 2004 book Evolution’s Rainbow: Diversity, Gender, and Sexuality in Nature and People."
What are we to infer about cultures that forcibly remove erogenous tissue (clitoris/clitoral hood/vulva on females and foreskin/frenulum/ridged band on males) from their children?
What are we to infer about cultures that forcibly remove erogenous tissue (clitoris/clitoral hood/vulva on females and foreskin/frenulum/ridged band on males) from their children?
The imagery and jokes in that article are pretty repulsive. And funny.
> "...there is a huge gaping hole in our knowledge of this very fundamental part of bird biology"
> Brennan’s husband is used to these kind of excursions: “He brings me roadkill as a nuptial gift,” she says.
> "...there is a huge gaping hole in our knowledge of this very fundamental part of bird biology"
> Brennan’s husband is used to these kind of excursions: “He brings me roadkill as a nuptial gift,” she says.
The image appears to show spirals in the same direction, not "opposite".
Uhm, no. Look again. The easiest way to tell is to think of the spiral as stacked, linked slashes like \ and /. Which direction does the top layer go? For the vagina, it's going /. For the penis, it's going \.
You're right! Thanks
"No one seemed to have an answer."
"..they both did a double-take. He had never seen anything like it. "
and, so on...
Interesting she did not ask the farmers where she purchased the ducks to get their insight...
"..they both did a double-take. He had never seen anything like it. "
and, so on...
Interesting she did not ask the farmers where she purchased the ducks to get their insight...
Do farmers investigate the inner workings of duck vaginas?
I did not make myself clear. Farmers have real-world observations, including duck parts. It never hurts for a scientist to hear external information that may be relevant, right or wrong.
Yeah, reasonable.
Looking at these structures dead and detached cannot show what agile, active organs they are in life. Study that and you have the last sexual kink that is still frowned on.
People describe a lot of very different taboos as “the last that is still frowned on”.
I am rather more troubled by the idea of someone “enjoying” these dead examples in that way. But I have the same trouble with leather fetishism for exactly the same reasons, and most do not share my negative reaction to the latter.
I wonder how that works, and why? Stream of consciousness here, but specifically about leather: could it be that the uncanny valley effect happens when the visual processing in our brains detect most of the signals to positively recognise an object, but missing a certain number of core features or possessing anti-features, and that my brain is trying to match again an unusual set of features such that leather induces this reaction in me — i.e. that it’s a person wearing someone else’s skin — whereas more normal people learned a substantially different set of feature detectors and just see leather as nothing more than a durable fabric?
I am rather more troubled by the idea of someone “enjoying” these dead examples in that way. But I have the same trouble with leather fetishism for exactly the same reasons, and most do not share my negative reaction to the latter.
I wonder how that works, and why? Stream of consciousness here, but specifically about leather: could it be that the uncanny valley effect happens when the visual processing in our brains detect most of the signals to positively recognise an object, but missing a certain number of core features or possessing anti-features, and that my brain is trying to match again an unusual set of features such that leather induces this reaction in me — i.e. that it’s a person wearing someone else’s skin — whereas more normal people learned a substantially different set of feature detectors and just see leather as nothing more than a durable fabric?
I think she has more research to do:
> That’s when she began thinking about conflict. Duck sex, she knew, could be notoriously violent. Ducks tended to mate for at least a season. However, extra males lurked in the wings, ready to harass and mount any paired female they could get their hands on.
I never knew ducks had hands! I thought that was only in cartoons! This is big news, even bigger than reverse-threaded vaginas.
> That’s when she began thinking about conflict. Duck sex, she knew, could be notoriously violent. Ducks tended to mate for at least a season. However, extra males lurked in the wings, ready to harass and mount any paired female they could get their hands on.
I never knew ducks had hands! I thought that was only in cartoons! This is big news, even bigger than reverse-threaded vaginas.
how scientific are this kind of explanations? “today we know that X% of duck sex is forced; that could explain why ducks have genitalia like they do”. the genitalia evolved over 10s or even 100s of thousands of years along with many other traits in ducks. we probably don’t know if ducks were so aggressive 200 years ago but we assume what we see today was the same 100k years ago?
I think maybe the "wild" thing isn't appropriate in an article that's actually about animals.
Super interesting story, I liked reading the exploration.
> Today, he admits that perhaps the reason he hadn’t considered looking at the female side of things was a result of his own male bias.
Honestly, the male scientists really disappointed me. Do they not have any curiosity or sense of professionalism? This guy dissected multiple penises and never once thought to dissect a vagina? Wow, just, wow.
> Today, he admits that perhaps the reason he hadn’t considered looking at the female side of things was a result of his own male bias.
Honestly, the male scientists really disappointed me. Do they not have any curiosity or sense of professionalism? This guy dissected multiple penises and never once thought to dissect a vagina? Wow, just, wow.
Alternate hypothesis: Scientists, even male ones, are social creatures. It is possible that a fair number of male scientists did think to dissect a vagina "back in the day". But then reconsidered - for reasons varying from "quiet concern that such scientific interests could be misinterpreted by polite society" to "feedback from peers was notably less enthusiastic on that subject" to "research funding and acceptance of papers for publication proved more difficult".
The two sentences immediately after your quote can be read this way:
> ...a result of his own male bias. “It was fitting that a woman followed this up,” he says. “We didn’t need a man to do it.”
The two sentences immediately after your quote can be read this way:
> ...a result of his own male bias. “It was fitting that a woman followed this up,” he says. “We didn’t need a man to do it.”
It's pretty easy to say that in hindsight but these people have a finite amount of research time and budget. Plus also mentioned in the article is that they actually had looked at vaginas before but dissected it in an incomplete way which lead to prior assumptions appearing valid when in fact they were not.
Oh, finally, a SMBC mystery thoroughly explained! (https://www.smbc-comics.com/comic/pokemon)
Male Barnacles are pretty wild and crazy guys, with penises eight times their body length, and their sweet romantic spermcasting! But those female Sacculina Carcini sure know how to keep their male mates in their place.
https://en.wikipedia.org/wiki/Barnacle#Sexual_reproduction
>Sexual reproduction
>Most barnacles are hermaphroditic, although a few species are gonochoric or androdioecious. The ovaries are located in the base or stalk, and may extend into the mantle, while the testes are towards the back of the head, often extending into the thorax. Typically, recently moulted hermaphroditic individuals are receptive as females. Self-fertilization, although theoretically possible, has been experimentally shown to be rare in barnacles.
>The sessile lifestyle of barnacles makes sexual reproduction difficult, as the organisms cannot leave their shells to mate. To facilitate genetic transfer between isolated individuals, barnacles have extraordinarily long penises . Barnacles probably have the largest penis to body size ratio of the animal kingdom, up to eight times their body length.
>Barnacles can also reproduce through a method called spermcasting, in which the male barnacle releases his sperm into the water and females pick it up and fertilise their eggs.
>The Rhizocephala superorder used to be considered hermaphroditic, but it turned out that its males inject themselves into the female's body, degrading to the condition of nothing more than sperm-producing cells.
https://en.wikipedia.org/wiki/Rhizocephala#Description_and_l...
>Description and lifecycle
>Sacculina carcini (adult female) parasiting a crab (Carcinus maenas). Haeckel's drawing also shows the internal network of filaments from the parasite.
>As adults they lack appendages, segmentation, and all internal organs except gonads, a few muscles, and the remains of the nervous system. Females also have a cuticle, which is never shed. Other than the minute larval stages, there is nothing identifying them as crustaceans or even arthropods in general. The only distinguishable portion of a rhizocephalan body is the externa; the reproductive portion of adult females.
>Nauplii released from adult females swim in water for several days without taking food (the larva has no mouth and no intestine) and transform into cypris larvae (cyprids) after several moults. Like the nauplii, the cyprids are lecithotrophic (non-feeding). The female cypris in Kentrogonida settles on a host and metamorphoses into a specialized juvenile form called a kentrogon, which has no visible segmentation and has no appendages except the antennules that are used to attach itself to the host, and whose only purpose is to inject a cell mass named the vermigon into the host's hemolymph through a retractive hollow stylet on its head. The kentrogon stage seems to have been lost in all of the Akentrogonida, where the cypris injects the vermigon through one of its antennules. The vermigon grows into root-like threads through the host's tissue, centering on the digestive system and especially the hepatopancreas, and absorb nutrients from the hemolymph. This network of threads is called the interna. The female then grows a sac-like externa, which consists of a mantle, a mantle cavity, an ovary and a pair of passageways known as cell receptacles, extruding from the abdomen of the host.
>In the order Kentrogonida, the virgin externa contains no openings at first. But it soon molts to a second stage that contains an orifice known as the mantle departure, and which leads into the two receptacle passageways — once assumed to be the testes in hermaphroditic parasites before the realization that they were actually two separate sexes — and starts releasing pheromones to attract male cyprids. From inside the body of the male cypris that succeeds in entering the departure, a unique and very short lived male stage called the trichogen emerges through the antennule opening. It is the homologue of the female kentrogon, but is reduced to an amoeboid unsegmented cuticle-covered mass of cells consisting of three to four cell-types: the dorsolateral, the ventral epidermis, the inclusion cells, and the postganglion. The externa have room for two males, one for each of the receptacles, which increase the heterozygosity of the offspring. Once inside, the trichogen will shed its cuticle before reaching the end of the passageway.
>In the order Akentrogonida, which form a monophyletic group nested within the paraphyletic Kentrogonida, the male does not develop into a trichogon, and the cypris injects its cell mass through its antennule and directly into the body of the immature externa. The offspring also hatch directly into fully developed cyprids instead of nauplius larvae (except for a few species of kentrogonid rhizocephalans, which hatch into cyprids like the akentrogonids, the kentrogonids have kept their nauplius stage). In species like Clistosaccus paguri, the male injects its cluster of cells which migrates through the connective tissue of the mantle and into the receptacle. But in forms like Sylon hippolytes the receptacle is absent, and the males cells implant in the ovary instead. While only a single male can settle in each receptacle, which is the rule in Kentrogonida, the number of implanted males in Akentrogonida can range from just one to more than ten.
>The small cluster of cells injected by the male cypris will, once it reaches its destination inside the female, differentiate into a loosely connected mass of sperm-producing germ cells. Being nothing more but sperm-forming cells, these adult male rhizocephalans represents the simplest form of male in the entire animal kingdom. Mature female externa releases eggs into its mantle cavity where eggs are fertilised by sperm from the hyper-parasitic male(s). Due to the larval sexual dimorphism in the Kentrogonida, the females produce two different egg sizes; small female eggs and larger male eggs. It appears the sex determination in Akentrogonida is environmental.
>In Peltogasterella gracilis, the externa produces several batches of larvae before it drops off the host, taking the male(s) inside with it. After the original externa disappear, the host moults and the interna grows buds that each develops into a new virgin externa. The females commonly has two cypris cell receptacles. With more than one externa, and new ones replacing the old ones, each female Peltogasterella can receive sperm from numerous males during its lifetime.
>The externa is where the host's egg sac would be, and the host's behaviour is chemically altered: it is castrated and does not moult until aged externa(e) drop(s) off. The host treats the externa as if it were its own egg sac. This behaviour even extends to male hosts, which would never have carried eggs, but care for the externa in the same way as females.
https://en.wikipedia.org/wiki/Barnacle#Sexual_reproduction
>Sexual reproduction
>Most barnacles are hermaphroditic, although a few species are gonochoric or androdioecious. The ovaries are located in the base or stalk, and may extend into the mantle, while the testes are towards the back of the head, often extending into the thorax. Typically, recently moulted hermaphroditic individuals are receptive as females. Self-fertilization, although theoretically possible, has been experimentally shown to be rare in barnacles.
>The sessile lifestyle of barnacles makes sexual reproduction difficult, as the organisms cannot leave their shells to mate. To facilitate genetic transfer between isolated individuals, barnacles have extraordinarily long penises . Barnacles probably have the largest penis to body size ratio of the animal kingdom, up to eight times their body length.
>Barnacles can also reproduce through a method called spermcasting, in which the male barnacle releases his sperm into the water and females pick it up and fertilise their eggs.
>The Rhizocephala superorder used to be considered hermaphroditic, but it turned out that its males inject themselves into the female's body, degrading to the condition of nothing more than sperm-producing cells.
https://en.wikipedia.org/wiki/Rhizocephala#Description_and_l...
>Description and lifecycle
>Sacculina carcini (adult female) parasiting a crab (Carcinus maenas). Haeckel's drawing also shows the internal network of filaments from the parasite.
>As adults they lack appendages, segmentation, and all internal organs except gonads, a few muscles, and the remains of the nervous system. Females also have a cuticle, which is never shed. Other than the minute larval stages, there is nothing identifying them as crustaceans or even arthropods in general. The only distinguishable portion of a rhizocephalan body is the externa; the reproductive portion of adult females.
>Nauplii released from adult females swim in water for several days without taking food (the larva has no mouth and no intestine) and transform into cypris larvae (cyprids) after several moults. Like the nauplii, the cyprids are lecithotrophic (non-feeding). The female cypris in Kentrogonida settles on a host and metamorphoses into a specialized juvenile form called a kentrogon, which has no visible segmentation and has no appendages except the antennules that are used to attach itself to the host, and whose only purpose is to inject a cell mass named the vermigon into the host's hemolymph through a retractive hollow stylet on its head. The kentrogon stage seems to have been lost in all of the Akentrogonida, where the cypris injects the vermigon through one of its antennules. The vermigon grows into root-like threads through the host's tissue, centering on the digestive system and especially the hepatopancreas, and absorb nutrients from the hemolymph. This network of threads is called the interna. The female then grows a sac-like externa, which consists of a mantle, a mantle cavity, an ovary and a pair of passageways known as cell receptacles, extruding from the abdomen of the host.
>In the order Kentrogonida, the virgin externa contains no openings at first. But it soon molts to a second stage that contains an orifice known as the mantle departure, and which leads into the two receptacle passageways — once assumed to be the testes in hermaphroditic parasites before the realization that they were actually two separate sexes — and starts releasing pheromones to attract male cyprids. From inside the body of the male cypris that succeeds in entering the departure, a unique and very short lived male stage called the trichogen emerges through the antennule opening. It is the homologue of the female kentrogon, but is reduced to an amoeboid unsegmented cuticle-covered mass of cells consisting of three to four cell-types: the dorsolateral, the ventral epidermis, the inclusion cells, and the postganglion. The externa have room for two males, one for each of the receptacles, which increase the heterozygosity of the offspring. Once inside, the trichogen will shed its cuticle before reaching the end of the passageway.
>In the order Akentrogonida, which form a monophyletic group nested within the paraphyletic Kentrogonida, the male does not develop into a trichogon, and the cypris injects its cell mass through its antennule and directly into the body of the immature externa. The offspring also hatch directly into fully developed cyprids instead of nauplius larvae (except for a few species of kentrogonid rhizocephalans, which hatch into cyprids like the akentrogonids, the kentrogonids have kept their nauplius stage). In species like Clistosaccus paguri, the male injects its cluster of cells which migrates through the connective tissue of the mantle and into the receptacle. But in forms like Sylon hippolytes the receptacle is absent, and the males cells implant in the ovary instead. While only a single male can settle in each receptacle, which is the rule in Kentrogonida, the number of implanted males in Akentrogonida can range from just one to more than ten.
>The small cluster of cells injected by the male cypris will, once it reaches its destination inside the female, differentiate into a loosely connected mass of sperm-producing germ cells. Being nothing more but sperm-forming cells, these adult male rhizocephalans represents the simplest form of male in the entire animal kingdom. Mature female externa releases eggs into its mantle cavity where eggs are fertilised by sperm from the hyper-parasitic male(s). Due to the larval sexual dimorphism in the Kentrogonida, the females produce two different egg sizes; small female eggs and larger male eggs. It appears the sex determination in Akentrogonida is environmental.
>In Peltogasterella gracilis, the externa produces several batches of larvae before it drops off the host, taking the male(s) inside with it. After the original externa disappear, the host moults and the interna grows buds that each develops into a new virgin externa. The females commonly has two cypris cell receptacles. With more than one externa, and new ones replacing the old ones, each female Peltogasterella can receive sperm from numerous males during its lifetime.
>The externa is where the host's egg sac would be, and the host's behaviour is chemically altered: it is castrated and does not moult until aged externa(e) drop(s) off. The host treats the externa as if it were its own egg sac. This behaviour even extends to male hosts, which would never have carried eggs, but care for the externa in the same way as females.
vmception(1)
Could the opposite spiral directions be just roughly the same structure but one is turned inside out?
I’m not up to speed on topology but generally turning things inside out changes the “handedness” (cf. a glove).
I’m not up to speed on topology but generally turning things inside out changes the “handedness” (cf. a glove).
Maybe "turned inside out" isn't getting the right idea across, since the "inside" of an orifice is still a continuation of the outside surface of the organism.
Instead picture one of those cabinets with the built-in gloves that are used for sandblasting or handing hazardous materials, and focus on the glove on the right side.
Normally a person's right hand would fit inside the glove (which as before is just a continuation of the outside surface of the cabinet).
Now pressurize the cabinet so that the glove pops out and inflates. The glove would now be in the shape of a left hand, and if you were to try and put a right-handed glove on it, it wouldn't fit.
There isn't really a profound takeaway here, other than maybe they're crediting a a genital arms race for something that is just an accident of related reproductive organs (there's a long list of these types of structures: https://en.wikipedia.org/wiki/List_of_related_male_and_femal...).
Instead picture one of those cabinets with the built-in gloves that are used for sandblasting or handing hazardous materials, and focus on the glove on the right side.
Normally a person's right hand would fit inside the glove (which as before is just a continuation of the outside surface of the cabinet).
Now pressurize the cabinet so that the glove pops out and inflates. The glove would now be in the shape of a left hand, and if you were to try and put a right-handed glove on it, it wouldn't fit.
There isn't really a profound takeaway here, other than maybe they're crediting a a genital arms race for something that is just an accident of related reproductive organs (there's a long list of these types of structures: https://en.wikipedia.org/wiki/List_of_related_male_and_femal...).
We don’t even understand how rocks evolved into life, so we will not know for quite some time…
We do know, though. We know the evolution of elemental matter, from the big bang through the formation of the solar system through the birth and the tectonic history of earth. We know that a particular combination of energetic environments and chemicals allowed a self reproducing process to take hold at least once. Because of the chirality of the chemistry of life, it's more likely that it developed on the surface, where solar radiation would select in that way, b but it could also have been thermal vents, underground springs, undersea volcanoes, or any of a set of locations that had the durability, energy, chemical availability, and border conditions that allowed cyclic processes to run the experiment a sufficient number of times for "life" to take hold.
We're missing a tiny blip of specificity in the history of life, but there's not anything particularly mysterious about it anymore. It's chemistry and time and probably vast scale and chaotic processes, but fundamentally and simply, it's a matter of chemistry and probability. There's no reason to ascribe to life life any special mystery over any other dynamic processes, like tides or orbits. We won the existence lottery, nothing more or less.
We're missing a tiny blip of specificity in the history of life, but there's not anything particularly mysterious about it anymore. It's chemistry and time and probably vast scale and chaotic processes, but fundamentally and simply, it's a matter of chemistry and probability. There's no reason to ascribe to life life any special mystery over any other dynamic processes, like tides or orbits. We won the existence lottery, nothing more or less.
A tiny blip called "how the entire thing started in the first place". This is a weak argument, honestly. The truth is there is no answer currently.
We know the limited range of conditions and requirements for how it started. We can replicate the chemistry of life - what I'm getting at is that we can rule out acts of God or magic. Successfully sparking the chemistry of life from scratch is still a profound and interesting endeavor, and might have value beyond things like the Drake equation and where to look for likely extraterrestrials.
I'm just saying the answer is sufficiently bounded that it's not very mysterious - there's not a lot of room for anything radically weird. We're not going to find out that the great spaghetti monster visits planets every hundred million years and deposits special life building nanobots. Panspermia, weird multiplanet exotic chemical exchange from massive impacts, etc are all possible contributors to the origin of life. Whatever the answer ends up being, modern science is 100% capable of replicating any chemical or physical occurrence that played a part.
It might require impractical scales of energy or mass - I personally suspect you need an ocean sized laboratory to achieve the variety of chemicals and sequences of processes to get the right mix of molecules that combine into replicators, and you need a lot of replicators before you get dynamic life that starts evolving. Complex amino acids have been found in asteroids and space debris, so maybe the spark was space junk?
It's a neat question but we're not looking for elan vital or anything fundamental anymore. We know what the mechanics of life are at a subatomic level, so the particular occurrence of life on earth is now a mystery similar to the interstellar origin story of matter in the solar system - we lack specifics but have a great general handle on how and why things are the way they are.
I'm just saying the answer is sufficiently bounded that it's not very mysterious - there's not a lot of room for anything radically weird. We're not going to find out that the great spaghetti monster visits planets every hundred million years and deposits special life building nanobots. Panspermia, weird multiplanet exotic chemical exchange from massive impacts, etc are all possible contributors to the origin of life. Whatever the answer ends up being, modern science is 100% capable of replicating any chemical or physical occurrence that played a part.
It might require impractical scales of energy or mass - I personally suspect you need an ocean sized laboratory to achieve the variety of chemicals and sequences of processes to get the right mix of molecules that combine into replicators, and you need a lot of replicators before you get dynamic life that starts evolving. Complex amino acids have been found in asteroids and space debris, so maybe the spark was space junk?
It's a neat question but we're not looking for elan vital or anything fundamental anymore. We know what the mechanics of life are at a subatomic level, so the particular occurrence of life on earth is now a mystery similar to the interstellar origin story of matter in the solar system - we lack specifics but have a great general handle on how and why things are the way they are.
You assume that the engine has to get started at some point. We have seen basic building blocks being produced in nature. We know how these building blocks can be assembled in self-replicating molecules that we would not consider “alive”. The engine is always working everywhere, it is just chemistry.
Now, there must have been specific conditions that lead to the production of some specific molecules, and we do not know all the details. These conditions are probably quite different from what we have on earth today, which does not help. There certainly is room for progress. But we do have a decent understanding of basic biochemistry.
Now, there must have been specific conditions that lead to the production of some specific molecules, and we do not know all the details. These conditions are probably quite different from what we have on earth today, which does not help. There certainly is room for progress. But we do have a decent understanding of basic biochemistry.
Surely the OP is aiming for a god of the gaps argument
Yes, it had that flavor to it, which prompted my response. Like minds as consciousness radios - we don't know how cognition works, but we know the brain is doing it. I'm arguing against mysticism, not curiosity or wonder at the awesomeness of the universe.
No, was just poking fun at these tautological pieces trying to explain everything like evolution has some goal in mind. :)
What is your threshold for 'knowing'?
Evolution by natural selection has been witnessed in modern times. Is there some reason to doubt the fossil record evidence that life has repeatedly developed from simpler forms toward more complex? (Albeit repeatedly as changing conditions caused some mass extinctions.)
Evolution by natural selection has been witnessed in modern times. Is there some reason to doubt the fossil record evidence that life has repeatedly developed from simpler forms toward more complex? (Albeit repeatedly as changing conditions caused some mass extinctions.)
Evolution explains how life evolves, but doesn’t explain the origin of life itself.
Evolution offers the most likely origin of life since it is simpler than all others that I've heard.
Evolution does not claim to explain the origin of life - only the, well, evolution of modern day species from primordial ones.
The origin of life - that is, how the very first ancestor in the chain came to be from simpler chemical processes - remains an active open area of research.
This isn't some faith based, moving the goal posts etc argument - its simple scientific fact: we don't yet know the chemical processes that can start with inorganic compounds and lead to a living cell. We will, some day, but we don't now.
The origin of life - that is, how the very first ancestor in the chain came to be from simpler chemical processes - remains an active open area of research.
This isn't some faith based, moving the goal posts etc argument - its simple scientific fact: we don't yet know the chemical processes that can start with inorganic compounds and lead to a living cell. We will, some day, but we don't now.
You can explain in detail how self sustaining life can evolve? Even the most die hard science minded people I know concede that's an unknown
It’s an unknown in the sense that it hasn’t been verified experimentally and we lack many details, but there are still quite a few things we know. The fact that we are not certain is not an excuse to claim that god did it and it is a failure of science, or that it is unknowable.
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Most likely, there is no origin of life. As in, there is nothing you can point to that is clearly alive and came from things that are clearly not.
Although it is complicated, we know a bit about the chemistry of self-replicating molecules. Things like prions and viruses also show that the boundary between alive and not-alive could be much more blurry than what most people have in mind when discussing such things.
Although it is complicated, we know a bit about the chemistry of self-replicating molecules. Things like prions and viruses also show that the boundary between alive and not-alive could be much more blurry than what most people have in mind when discussing such things.
Ever since bjork's "biophilia" album I have considered it a gradient between crystals and biology: they both use atoms in their surrounding to create copies of their structure.
Stone does so in a temperature gradient in the environment (atoms crystallizing as they precipitate out of solution) while Life is able to store enough energy in itself to impose structure (trading energy for entropy) on surrounding atoms even when the environment would otherwise dissolve it. The threshold for 'life' is replicating even when conditions are not perfect, that's survival.
(on another note, we would never have discovered DNA if not for the same x-ray techniques being used to analyze the symmetries of stone)
Stone does so in a temperature gradient in the environment (atoms crystallizing as they precipitate out of solution) while Life is able to store enough energy in itself to impose structure (trading energy for entropy) on surrounding atoms even when the environment would otherwise dissolve it. The threshold for 'life' is replicating even when conditions are not perfect, that's survival.
(on another note, we would never have discovered DNA if not for the same x-ray techniques being used to analyze the symmetries of stone)
Hm? Evolution explains why life evolves in particular directions. But it has nothing to say about how changes occur; instead, it assumes that changes occur and discusses which changes persist and which don't.
From the perspective of "evolution", there is no difference between a strand of RNA mutating into a different strand of RNA and a cluster of vaguely RNA-like chemicals mutating into a strand of RNA. Those are both things that are outside the scope of evolutionary theory.
From the perspective of "evolution", there is no difference between a strand of RNA mutating into a different strand of RNA and a cluster of vaguely RNA-like chemicals mutating into a strand of RNA. Those are both things that are outside the scope of evolutionary theory.
Evolution is just a fancy word we put on what we see in living things, but there is nothing magic in DNA or RNA. In an abstract sense, the emergence of some specific complex molecules from a bunch of precursors also is selection of the fittest (most stable, with the lowest energy of formation, etc). These are things at play in the production of amino acids in thermal vents, for example.
Isn't that what I'm saying?
Indeed. I intended it more as a complement than an argument against your post.
How, not if. What sparked the first forms of life? No one knows.
This is literally not the preserve of evolution (as a concept or as a formal area of study).
The relevant study is the field of abiogenesis:
https://en.wikipedia.org/wiki/Abiogenesis
The relevant study is the field of abiogenesis:
https://en.wikipedia.org/wiki/Abiogenesis
Seems to be a blurry boundary. Chemists talk about evolving reactions, people study the possible routes for rock chemistry to evolve into cells (abiogenesis), etc.
From a linked article (https://www.newyorker.com/tech/annals-of-technology/duck-sex...):
A female duck’s vaginal barriers cannot shield her from physical harm. On an evolutionary level, though, they protect her in another way—by allowing her to choose the father of her offspring.
By using her vaginal barriers, she is able to maintain her sexual autonomy in the face of sexual violence.
Our observations also revealed that when a female duck solicits sex with a chosen mate, her cloacal muscles dilate to allow uninhibited entry.
The result is that, even for species in which nearly forty per cent of all copulations are violently coerced, only between two and five per cent of ducklings come from extra-pair matings. As a method of contraception, ducks’ vaginal barriers can be ninety-eight-per-cent effective...
Is there an equivalent mechanism in human females? Why yes, there is. As one would expect, it's framed as a 'disorder': https://en.wikipedia.org/wiki/Vaginismus
No one has seriously examined this as a natural defense against coerced sex, but maybe it's time...
A female duck’s vaginal barriers cannot shield her from physical harm. On an evolutionary level, though, they protect her in another way—by allowing her to choose the father of her offspring.
By using her vaginal barriers, she is able to maintain her sexual autonomy in the face of sexual violence.
Our observations also revealed that when a female duck solicits sex with a chosen mate, her cloacal muscles dilate to allow uninhibited entry.
The result is that, even for species in which nearly forty per cent of all copulations are violently coerced, only between two and five per cent of ducklings come from extra-pair matings. As a method of contraception, ducks’ vaginal barriers can be ninety-eight-per-cent effective...
Is there an equivalent mechanism in human females? Why yes, there is. As one would expect, it's framed as a 'disorder': https://en.wikipedia.org/wiki/Vaginismus
No one has seriously examined this as a natural defense against coerced sex, but maybe it's time...
> Our observations also revealed that when a female duck solicits sex with a chosen mate, her cloacal muscles dilate to allow uninhibited entry.
> Is there an equivalent mechanism in human females? Why yes, there is. As one would expect, it's framed as a 'disorder': https://en.wikipedia.org/wiki/Vaginismus
Hve you tried putting these two pieces of the puzzle together? They are pretty clear I think: Vaginismus is a disorder because it affects women who are trying to have consensual sexual relations. If it were only happening when someone was trying to coerce sexual relations, it would NOT have been labeled a disorder.
Simple as that.
> Is there an equivalent mechanism in human females? Why yes, there is. As one would expect, it's framed as a 'disorder': https://en.wikipedia.org/wiki/Vaginismus
Hve you tried putting these two pieces of the puzzle together? They are pretty clear I think: Vaginismus is a disorder because it affects women who are trying to have consensual sexual relations. If it were only happening when someone was trying to coerce sexual relations, it would NOT have been labeled a disorder.
Simple as that.
From Wikipedia (with references): However, the term vaginismus is sometimes used more broadly to refer to any muscle spasms occurring during the insertion of some or all types of objects into the vagina, sexually motivated or otherwise, including the usage of speculums and tampons.
So not necessarily a disorder, but a reaction; and if that's the case, it deserves more investigation, particularly given how widespread rape is.
Then women might not need something like Rape-aXe (https://rape-axe.com/)
So not necessarily a disorder, but a reaction; and if that's the case, it deserves more investigation, particularly given how widespread rape is.
Then women might not need something like Rape-aXe (https://rape-axe.com/)
Yes, the spasms by themselves are not a disorder. They're only considered a disorder when the woman is trying to have consensual sex. I honestly don't know what argument you're trying to put forward.
>Then women might not need something like Rape-aXe (https://rape-axe.com/)
The spasms by themselves are ineffective at preventing forceful penetration. If they were effective there would be no rape, or at least no penetrative vaginal rape. The reason such a device is desired is precisely because it's ineffective.
>Then women might not need something like Rape-aXe (https://rape-axe.com/)
The spasms by themselves are ineffective at preventing forceful penetration. If they were effective there would be no rape, or at least no penetrative vaginal rape. The reason such a device is desired is precisely because it's ineffective.
> So not necessarily a disorder, but a reaction; and if that's the case, it deserves more investigation, particularly given how widespread rape is.
Is there widespread evidence of rape victims experiencing vaginismus as a protective reaction at the moment of attack (as opposed to them experiencing it as a disorder in a post-rape-trauma context?)
Is there widespread evidence of rape victims experiencing vaginismus as a protective reaction at the moment of attack (as opposed to them experiencing it as a disorder in a post-rape-trauma context?)
If I unserstand it right, this is in ducks a defense against contraception, not against coerced sex.
Further, if this is supposed to be an argument against legal abortion (I heard before from the anti-abortion crowd, that the body has defenses against unwanted pregnamcy), then the question becomes if this really can be willfully controlled and if we really want to limit the choice making of women to that short period of time, when they are being violated.
I think the disorder comes in, when women complain about it to their doctors, i.e. they are unable to control it. So I don't see a reason why it should be considered anything else in such circumstances.
Further, if this is supposed to be an argument against legal abortion (I heard before from the anti-abortion crowd, that the body has defenses against unwanted pregnamcy), then the question becomes if this really can be willfully controlled and if we really want to limit the choice making of women to that short period of time, when they are being violated.
I think the disorder comes in, when women complain about it to their doctors, i.e. they are unable to control it. So I don't see a reason why it should be considered anything else in such circumstances.
> Further, if this is supposed to be an argument against legal abortion (I heard before from the anti-abortion crowd, that the body has defenses against unwanted pregnamcy)
Most notably the GOP Rep[0] Todd Akin:
https://en.wikipedia.org/wiki/Todd_Akin#Comments_on_%22legit...
[0] short for "reprehensible" in this case
Most notably the GOP Rep[0] Todd Akin:
https://en.wikipedia.org/wiki/Todd_Akin#Comments_on_%22legit...
[0] short for "reprehensible" in this case
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I just wish the cultural revolution wasn’t so vapid and superficial.
"Eschew flamebait. Avoid unrelated controversies and generic tangents."
https://news.ycombinator.com/newsguidelines.html
https://news.ycombinator.com/newsguidelines.html
Care to explain what you mean by that statement?
Sure - the article is written in the language and tone of a 9th grader. It’s a trite approach and although I get the mass appeal perhaps, it’s rather boring.
It seems pretty clear, and reasonably engaging. Plain, at worst. Are you sure you're not just a fan of flowery language? Also, what cultural revolution is the grade level of this writing related to? That's a pretty cryptic implication.
I assume you mean:
> He suggested that perhaps the male was responding to female preference—wink-wink, nudge-nudge—but hadn’t bothered to actually examine the female.
I think "wink-wink nudge-nudge" is an unfair characterisation of someone's motivation to dissect duck genitals. It's a statement about evolutionary pressure, not a bawdy joke.
> He suggested that perhaps the male was responding to female preference—wink-wink, nudge-nudge—but hadn’t bothered to actually examine the female.
I think "wink-wink nudge-nudge" is an unfair characterisation of someone's motivation to dissect duck genitals. It's a statement about evolutionary pressure, not a bawdy joke.
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Brennan dissects a female coachwhip snake in her lab at Mt. Holyoke College in Massachusetts in September 2021. “This is my happy place,” she says.
Brennan really love science. And genitals. And vivisections.
Brennan really love science. And genitals. And vivisections.
"Vivisection" involves a living creature.
Nothing wrong with loving science, genitals, or dissection…