Female African elephants are evolving without tusks due to ivory poaching(theswaddle.com)
theswaddle.com
Female African elephants are evolving without tusks due to ivory poaching
https://theswaddle.com/female-african-elephants-are-evolving-without-tusks-due-to-ivory-poaching/
319 comments
> It started off about as common as humans having green eyes.
Elephant poaching has been around since long before the Mozambique civil war. The number of tuskless elephants may have been at 2-4% prior to the war, but that doesn't mean that lower levels of poaching didn't push it up to that level from some much lower naturally-occurring level.
2-4% seems like a _very high_ rate for a trait that could negatively impact a female's chance of survival AND kills 100% of her male offspring.
Elephant poaching has been around since long before the Mozambique civil war. The number of tuskless elephants may have been at 2-4% prior to the war, but that doesn't mean that lower levels of poaching didn't push it up to that level from some much lower naturally-occurring level.
2-4% seems like a _very high_ rate for a trait that could negatively impact a female's chance of survival AND kills 100% of her male offspring.
Further to your point, I read elsewhere that the base rate in captivity is closer to 0.5%.
Human behavior probably has the opposite effect in captive elephants. If a captive elephant is born without tusks then the Mahout is going to kill it rather than invest in rearing an animal that has much reduced utility and will not yield healthy offspring.
Elephants are not really bread in captivity.
They are bread in captivity. In Europe the breeding is organized by the European Endangered Species Programme.
https://nhatrangbay.net.vnwww.eaza.net/assets/Uploads/EAZA-D...
https://www.elephant.se/elephant_breeding_in_europe.php
https://nhatrangbay.net.vnwww.eaza.net/assets/Uploads/EAZA-D...
https://www.elephant.se/elephant_breeding_in_europe.php
I highly doubt those elephants are getting killed if they don't have tusks, though.
While that's generally true, there are exceptions. Elephants at the Oregon Zoo have birthed more than two dozen babies over the past several decades. https://www.oregonzoo.org/node/1948/media
Evolution is an umbrella term, but in the most general form, evolution means a change in genetics in a population over time. So yes, the genetic 'option' was there before, but it is advantageous now.
Not only is it more advantageous, it actually was force selected for (IIRC, poached elephants are often left for dead). So this is closer to selective breeding/artificial selection more so than natural selection.
What's the difference in this case? Doesn't seem too different from how camouflaged eggs would have developed (maybe just faster because the selection mechanism is so strong).
When I think of selective breeding I think of humans picking out which animals (cows/dogs/wheat/etc) get to reproduce.
When I think of selective breeding I think of humans picking out which animals (cows/dogs/wheat/etc) get to reproduce.
Right, selective breeding is just a subset of natural selection. Not sure why folks seem to want to exclude humans from nature, like we’re not part of the exact same system.
You’ve got it backwards. ‘Natural selection’ was coined to point out that selective forces exist in the wild other than humans deliberately breeding selected animals, which was well known in Darwin’s time. There’s ‘selection’ by humans and ‘natural selection’ which is by effects other than human selection. The effects of human hunting are a boundary case, where the selection pressure is not intended, but is a ‘natural’ consequence.
> Not sure why folks seem to want to exclude humans from nature
Probably because the concept of "nature" no longer serves any purpose if you don't, as it doesn't exclude anything.
It's often a pointless distinction to make (see also: anything that labels itself as "organic"), but it's a convenient shorthand to describe a category of interactions that people often want to talk about.
Probably because the concept of "nature" no longer serves any purpose if you don't, as it doesn't exclude anything.
It's often a pointless distinction to make (see also: anything that labels itself as "organic"), but it's a convenient shorthand to describe a category of interactions that people often want to talk about.
Perhaps, then, "nature" is a somewhat dated concept that is no longer especially useful to have in such broad circulation, given that it encourages folks to exclude humanity from analysis and understanding of the "natural" system?
That's precisely what the article linked points out.
Except it's only advantageous to female elephants, according to the article:
"They identified two likely genes AMELX and MEP1a, which are passed from mothers to the offspring on the X chromosome. But if a disrupted gene is passed in a male elephant, the elephant dies; the female elephant would instead evolve to be born without tusks. "
What would be the effect of this on male elephant population when taken to the limit (i.e. 100% of females are tuskless)? Seems to me that it'd skew the proportion of births towards 2:1 (assuming it's now at 1:1)? How significant impact would that have to the species as a whole?
"They identified two likely genes AMELX and MEP1a, which are passed from mothers to the offspring on the X chromosome. But if a disrupted gene is passed in a male elephant, the elephant dies; the female elephant would instead evolve to be born without tusks. "
What would be the effect of this on male elephant population when taken to the limit (i.e. 100% of females are tuskless)? Seems to me that it'd skew the proportion of births towards 2:1 (assuming it's now at 1:1)? How significant impact would that have to the species as a whole?
Warning: guesswork. If only females survive with this disruption, it can only be inherited from a mother, so only 1 X chromosome of a female can have it. If somehow only those females survive, there's a pool of 50% of X chromosomes of females with the mutation. The following generation would be born with half of the female population with the mutation (25% of female X chromosomes), and half of the male population dead. The following one, without artificial selection, would have a fourth of mutated females and dead males. So this mutation tends to just disappear without selective pressure.
So while a tuskless female may generate 2:1 females to males, that's (hopefully, depending on poaching) far from a stable birth ratio for the population, though active poaching may cause the female to male ratio for living specimens can be further skewed much higher than 2:1.
So while a tuskless female may generate 2:1 females to males, that's (hopefully, depending on poaching) far from a stable birth ratio for the population, though active poaching may cause the female to male ratio for living specimens can be further skewed much higher than 2:1.
I'm a layman in genetics, but I believe the effect you described is what is known as Fisher's principle.
Basically, when using sexual reproduction, it _would_ be highly effective for the species to have many more females than males, since females are the bottleneck of population growth. However, if the sex ratio is skewed then any traits which increases the likelihood of male offspring will enjoy a reproductive advantage (because the male offspring will itself have more offspring than the females), spread through the next generation, and reduce the sex ratio, until it reaches the balance of 50/50. This applies whether the trait is dominant or regressive, etc.
So in this scenario, as the tuskless mutation spreads, the number of males decreases and the genetic advantage of having tusks grows, until it balances out the genetic disadvantage of losing females to poachers.
Basically, when using sexual reproduction, it _would_ be highly effective for the species to have many more females than males, since females are the bottleneck of population growth. However, if the sex ratio is skewed then any traits which increases the likelihood of male offspring will enjoy a reproductive advantage (because the male offspring will itself have more offspring than the females), spread through the next generation, and reduce the sex ratio, until it reaches the balance of 50/50. This applies whether the trait is dominant or regressive, etc.
So in this scenario, as the tuskless mutation spreads, the number of males decreases and the genetic advantage of having tusks grows, until it balances out the genetic disadvantage of losing females to poachers.
> So this mutation tends to just disappear without selective pressure.
I think you are making a good case for that conclusion, and would that not imply that the mutation - or, more specifically, its most recent manifestation - arose fairly recently, i.e. subsequent to hunting for ivory becoming a serious problem for elephants?
I think you are making a good case for that conclusion, and would that not imply that the mutation - or, more specifically, its most recent manifestation - arose fairly recently, i.e. subsequent to hunting for ivory becoming a serious problem for elephants?
Maybe not as much as you would think. Naturally, not all males mate and the mating ratio is not always 1:1. Take humans for example, it's been shown our ancestors comprise mostly of females in a ratio roughly 3:2 to males. That is, some male ancestor probably mated with more than one female ancestor somewhere.
I don't know what the numbers are like for elephants, but in many species, most males don't get to mate at all, and a handful of dominant males mate prodigiously. Even if tuskless males were viable, they'd fail miserably at mating if there were tusked males around, because they'd get their asses kicked.
>our ancestors comprise mostly of females in a ratio roughly 3:2 to males.
For anyone else wondering how this is possible on an individual level, apparently a lot of people used to reproduce with their first and second cousins.
For anyone else wondering how this is possible on an individual level, apparently a lot of people used to reproduce with their first and second cousins.
I do not understand how mating with a 1st or 2nd cousin affects the ratio of females to males. Could you explain?
Assume that Bob knocks up both Alice and Eve.
Alice has a son, Eve has a daughter.
Alice's son knocks up Eve's daughter.
Their kid will have two biological grandmothers, but only one biological grandfather.
Apparently, historically, this type of thing was quite common and could heavily skew family trees towards the female side of things.
Alice has a son, Eve has a daughter.
Alice's son knocks up Eve's daughter.
Their kid will have two biological grandmothers, but only one biological grandfather.
Apparently, historically, this type of thing was quite common and could heavily skew family trees towards the female side of things.
That skews the tree shape, but the odds of each baby are still ~50/50 so the overall population numbers should be stable.
The overall population is roughly 50:50, but men are more likely to be the "final node" in the family tree.
Let's adjust the example above slightly to include Bob's friend Darren, who who never got laid because he spent his whole life watching pornography and playing video games.
Even in this case, despite the 50:50 ratio of males and females both across society as a whole and within each generation, the child has more male ancestors.
This will be the case for any sufficiently large population where males have more variance in reproductive success than females, and people (of either sex) reproduce with others who have a shared ancestor (the closer the ancestor, the greater the effect the variance has on the ratio of male to female ancestors).
Let's adjust the example above slightly to include Bob's friend Darren, who who never got laid because he spent his whole life watching pornography and playing video games.
Even in this case, despite the 50:50 ratio of males and females both across society as a whole and within each generation, the child has more male ancestors.
This will be the case for any sufficiently large population where males have more variance in reproductive success than females, and people (of either sex) reproduce with others who have a shared ancestor (the closer the ancestor, the greater the effect the variance has on the ratio of male to female ancestors).
Aussie was demonstrating how an individual could have more male ancestors than female ancestors. And his very simple example did in fact provide the 3:2 ratio that was previously mentioned.
I think I misunderstood the proposition. Sorry.
It doesn't because mating cousins is likely the effect of a skewed population,not the cause.
(im not a historian so this is speculation)
I imagine that early humans had divided roles, and roles assigned to males involved more danger. (bearing in mind that the state of medicine meant that relatively minor incidents by our standards could lead to infection and death in theirs.)
So populations start out 50/50,but skew badly once men age enough to take on dangerous work.
This leads to men having multiple partners and the scenario mentioned in the sibling comment.
(im not a historian so this is speculation)
I imagine that early humans had divided roles, and roles assigned to males involved more danger. (bearing in mind that the state of medicine meant that relatively minor incidents by our standards could lead to infection and death in theirs.)
So populations start out 50/50,but skew badly once men age enough to take on dangerous work.
This leads to men having multiple partners and the scenario mentioned in the sibling comment.
Still not that uncommon in few parts of the world.
> it's been shown our ancestors comprise mostly of females in a ratio roughly 3:2 to males.
I thought it was 2:1.
I thought it was 2:1.
And this is why genetic diversity is a good thing.
Hmm in the context of the article, I'm not so sure it's a good thing.
Later on they mention that if this genetic trait gets passed on to males, they die. So along with hunting, males are doubly at risk.
It may be advantageous for the survival of an individual to be born without tusks, but it doesn't sound too good for the survival of the species.
Later on they mention that if this genetic trait gets passed on to males, they die. So along with hunting, males are doubly at risk.
It may be advantageous for the survival of an individual to be born without tusks, but it doesn't sound too good for the survival of the species.
The trait may or may not be advantageous. Diversity is. In this case the selective pressure is poaching, but selective pressures are constant. Diversity is a bank of genetics that the population can draw from to adapt and survive.
Traits that are rare, are often rare because of shortcomings. But if environmental changes make that tradeoff worthwhile, it can be made. Meanwhile, evolution doesn't stop. Once the trait/gene is common there is positive selective pressure on complementary genes. Over time, these may mitigate or compensate for the negative traits that have acquired.
Of course, on the timescales that humans tend to selectively pressure species, there isn't time for all this elegance to emerge, usually.
Traits that are rare, are often rare because of shortcomings. But if environmental changes make that tradeoff worthwhile, it can be made. Meanwhile, evolution doesn't stop. Once the trait/gene is common there is positive selective pressure on complementary genes. Over time, these may mitigate or compensate for the negative traits that have acquired.
Of course, on the timescales that humans tend to selectively pressure species, there isn't time for all this elegance to emerge, usually.
This is all true. You make very good points.
My parent said:
> And this is why genetic diversity is a good thing.
I guess what I meant was: genetic diversity is a good thing. But this particular case is not a great example for illustrating why.
My parent said:
> And this is why genetic diversity is a good thing.
I guess what I meant was: genetic diversity is a good thing. But this particular case is not a great example for illustrating why.
Why do they die? Because they can't protect themselves? Or does the trait come with other less desirable side effects for males?
The trait appears to be lethal to males and they do not make it to birth.
It may be the case that at least one typical X chromosome is necessary for survival, and males only get one X chromosome.
It may be the case that at least one typical X chromosome is necessary for survival, and males only get one X chromosome.
Yes, but in the long run isn't this breeding out this specific diversity? I recall reading that genetic diversity becoming limited in endangered species makes them much more susceptible to being wiped out by disease.
Evolution has two main components.
The random variation was already there. The natural selection is doing its part now.
I thought evolution's components were sexual selection (who fucks) and natural selection (who dies). Random variation can change genes, yeah, but evolution is driven through the dis/advantages of the resulting phenotype (do they succeed at finding a mate, do they raise as man offspring to sexual maturity and do they survive long enough to do the aforementioned).
This is selective breeding / artificial selection, not natural selection.
If it were some other predator, we'd say it's natural selection. Because it's humans killing the ones with certain traits we say it's artificial? But humans are not doing it to promote a certain trait, in fact the evolutionary effect of the poaching is actually the opposite of what people want.
No, it's not. People are not choosing pairs of elephants to breed.
It may be unintentional, but it is still artificial.
Define "artificial".
Oof, that's a tall order, isn't it? I'm no professional philosopher, and not somebody who works all day making dictionary definitions, but the general sense of natural / artificial here is "not by humans" versus "by humans", although that's not very precise and you'll get into trouble if you read too much into much into it. There are loads of ways in which you'd need to refine this definition in order to account for various exceptions (due to convention) or the ways in which the sense is incompletely explained (e.g. it would be "natural" for me to drink water, but "artificial" to manufacture sunglasses).
Words like "natural" and "artificial" don't admit tidy definitions, and you know that, which is why you demanded that I define it for you, presumably so you could poke holes in whatever definition I provided.
Words like "natural" and "artificial" don't admit tidy definitions, and you know that, which is why you demanded that I define it for you, presumably so you could poke holes in whatever definition I provided.
> which is why you demanded that I define it for you, presumably so you could poke holes in whatever definition I provided
Not really. Your original use of the word implied the definition you were using, and my comment was merely to point out that it's the wrong definition (in my opinion, obviously).
In this context it makes more sense to include the intention, because the evolution itself in this case is not something we artificially induced.
The elephants, for example, might have evolved to have green tusks instead, which would have made them not attractive to poachers. They could have grown wings that would made them more difficult to be hunted. The point is, poaching might be artificial, but the elephants responded to a threat (coming from humans or not) with a completely random and natural process.
Not really. Your original use of the word implied the definition you were using, and my comment was merely to point out that it's the wrong definition (in my opinion, obviously).
In this context it makes more sense to include the intention, because the evolution itself in this case is not something we artificially induced.
The elephants, for example, might have evolved to have green tusks instead, which would have made them not attractive to poachers. They could have grown wings that would made them more difficult to be hunted. The point is, poaching might be artificial, but the elephants responded to a threat (coming from humans or not) with a completely random and natural process.
> Not really. Your original use of the word implied the definition you were using, and my comment was merely to point out that it's the wrong definition (in my opinion, obviously).
That's precisely what I said... you asked me to provide the definition in order to poke holes in it. Rather than go through this back-and-forth nonsense with implications, why not just say it up front?
Anyway, seems like you think I was saying that the evolution was artificial. Evolution is heritable variation and the forces that choose among those variations. Natural selection, artificial selection, and genetic drift are possible forces that choose the variation, but in this case, the variations themselves are still random mutations.
That's precisely what I said... you asked me to provide the definition in order to poke holes in it. Rather than go through this back-and-forth nonsense with implications, why not just say it up front?
Anyway, seems like you think I was saying that the evolution was artificial. Evolution is heritable variation and the forces that choose among those variations. Natural selection, artificial selection, and genetic drift are possible forces that choose the variation, but in this case, the variations themselves are still random mutations.
You're saying poachers intentionally breed tuskless elephants so they don't have to hunt anymore?
... Evolution has three main components
Sure, and two of them are identical from every practical and theoretical perspective.
[deleted]
There are more main components than that. Sometimes forces like drift are stronger than adaptive selection.
A man with a gun doesn't sound like "natural selection".
Why not? I often see people draw this distinction between humanity and nature, as if we weren't part of nature, and there is something deeply misanthropic about it. Of course we are part of nature. We may be screwing over the habitat of other animals -- like rabbits in Australia or pythons in the everglades -- but we are certainly part of nature and this is a textbook case of natural selection at work.
That is exactly what the distinction "natural / artificial" means... it's not some kind of judgment. In this sense of the word, artificial just means "by humans".
"artificial selection" means people selectively breeding for traits they find desirable [0] [1]. e.g. "I want a short-legged dog, so I'm going to keep breeding the shortest-legged dog from each generation together." That's not what's happening here. The poachers aren't trying to create tuskless elephants.
You can't peel off the "natural" in "natural selection" in this case and say "because this is done by humans, it's artificial selection," when artificial selection already has a distinct meaning.
[0]: https://en.wikipedia.org/wiki/Selective_breeding [1]: https://www.nationalgeographic.org/encyclopedia/artificial-s...
You can't peel off the "natural" in "natural selection" in this case and say "because this is done by humans, it's artificial selection," when artificial selection already has a distinct meaning.
[0]: https://en.wikipedia.org/wiki/Selective_breeding [1]: https://www.nationalgeographic.org/encyclopedia/artificial-s...
That is also an incoherent distinction. If humans ferment milk to make cheese, then this is "artificial" food? No, I think people use "natural" and "artificial" to mean "traditional practice" versus "modern practice", but humans do all of it.
Yes, it turns out that the English language is full of incoherent distinctions. Words mean radically different things in different contexts, have definitions that are not really self-consistent, and tons of exceptions that we have to memorize. And yet, we must make sense of it to navigate.
If I were a philosopher, or if I wrote dictionary entries, I might decide to spend the time to come up with a rather clever definition for "artificial". Feel free to come up with a definition yourself, if that's your fancy.
If I were a philosopher, or if I wrote dictionary entries, I might decide to spend the time to come up with a rather clever definition for "artificial". Feel free to come up with a definition yourself, if that's your fancy.
I think the underlying bugaboo is "untested", particularly when referring to something considered "fragile".
People trust traditional techniques of preparing food because they have proven successful at their intended goals. When you start messing with people's food, they become suspicious as to whether you know the full repercussions of what you are doing.
So the injection of a novel element is considered "artificial" - despoiling the "natural" -- e.g. time-tested technique, and possibly disturbing something fragile -- e.g. human health.
Similarly, people are quite reactionary when it comes to open spaces and nature because they see a system that appears to be in balance and has survived the test of time. They oppose altering the current state of affairs because they are sure some unintended side effect will screw things up.
On the one hand, it's laudable to have these goals, but if they used the standard language of conservatism, traditionalism, etc, they would be branded as reactionaries, so the spirit of the age is to invent new words like "artificial" and "natural" that are less loaded with politics, even though it is all just conservatism at its roots.
People trust traditional techniques of preparing food because they have proven successful at their intended goals. When you start messing with people's food, they become suspicious as to whether you know the full repercussions of what you are doing.
So the injection of a novel element is considered "artificial" - despoiling the "natural" -- e.g. time-tested technique, and possibly disturbing something fragile -- e.g. human health.
Similarly, people are quite reactionary when it comes to open spaces and nature because they see a system that appears to be in balance and has survived the test of time. They oppose altering the current state of affairs because they are sure some unintended side effect will screw things up.
On the one hand, it's laudable to have these goals, but if they used the standard language of conservatism, traditionalism, etc, they would be branded as reactionaries, so the spirit of the age is to invent new words like "artificial" and "natural" that are less loaded with politics, even though it is all just conservatism at its roots.
Humans are animals and predators like any other in this situation.
Why downvote parent? A human is a "natural" predator just with different methods of attack/more intelligence than "animals". Why is a human predator (an "apex predator" if you will) any less "natural" than a T-Rex? Or any other animal that forced evolutionary change?
Because of civilization. While the word "artificial" is certainly overloaded, this is basically what we've designated the word to mean. That's not to say a human couldn't be a "natural" predator, if you assumed an isolated tribe, but that's certainly not what's happening here. If we call this natural, there is no longer any meaning you can ascribe to artificial.
Is this actually evolution?
I ask because it’s not a change in the genetic structure of elephants. It’s an existing trait becoming more wide spread.
I ask because it’s not a change in the genetic structure of elephants. It’s an existing trait becoming more wide spread.
Yes, this is evolution, and that's generally how evolution works. There is some diversity in a population, and natural selection promotes some traits over others.
Looking at definitions in dictionaries I don’t see this. What am I missing? Honest question.
There are no new species and there is no change to genetic code
There are no new species and there is no change to genetic code
There is something here that is much more general than this particular issue: dictionary definitions of scientific concepts (and those in many other fields) are merely summaries, and far from being the last word on the matter (you can't learn quantum mechanics from a dictionary.)
It is not uncommon, in forums like HN, for there to be arguments over the 'true' definition of a word, but unless the issue being debated is lexicographical, these arguments are usually missing the point. While it is the case that the teaching of a subject often begins with some definitions, that is only the beginning, and it is usually done to shortcut the difficult process by which those definitions came to be written in the first place. On reflection, it should be clear that the definitions cannot be written (or, at least, finalized) until after we have gained an understanding of that which we are defining.
What we are observing here is the selection part of evolution. We did not observe the origination of the mutation causing the trait being acted on by selection, but it is empirically established that it is not uncommon for such mutations to occur. Nor have we seen it play out fully, where the trait, and the mutation causing it, become ubiquitous, and other alleles disappear (if the selection pressure continues and the species does not become extinct.) Here, we are observing evolution in progress, not its ultimate result.
This change alone will not create a new species, but if enough changes occur that the descendants could not, in principle, breed successfully with their ancestors, then it has. We can see a precursor to this in the mutation being lethal in males.
It is not uncommon, in forums like HN, for there to be arguments over the 'true' definition of a word, but unless the issue being debated is lexicographical, these arguments are usually missing the point. While it is the case that the teaching of a subject often begins with some definitions, that is only the beginning, and it is usually done to shortcut the difficult process by which those definitions came to be written in the first place. On reflection, it should be clear that the definitions cannot be written (or, at least, finalized) until after we have gained an understanding of that which we are defining.
What we are observing here is the selection part of evolution. We did not observe the origination of the mutation causing the trait being acted on by selection, but it is empirically established that it is not uncommon for such mutations to occur. Nor have we seen it play out fully, where the trait, and the mutation causing it, become ubiquitous, and other alleles disappear (if the selection pressure continues and the species does not become extinct.) Here, we are observing evolution in progress, not its ultimate result.
This change alone will not create a new species, but if enough changes occur that the descendants could not, in principle, breed successfully with their ancestors, then it has. We can see a precursor to this in the mutation being lethal in males.
genetics is random. Each new generation combines genetic material from their ancestors, plus some new random mutations.
natural selection, i.e. the environment they're born in, is what picks winners and losers among those inherited characteristics and mutations.
Almost all individual mutations on a genetic level are benign. It's the combination of (selection of specific trait + compounding change) that is what we know as evolution.
In this case, the "change to the genetic code" produces elephants without tusks. That happened by change. But now, the elephants without tusks are the ones who get to live, because they're not poached. That specific mutation allows them to live/thrive. In the same way better hearing might allow a bird to evade its predators.
"no change to genetic code" ignores the fact that there are elephants wandering around who don't have (and will never have) tusks. (also: evolution is quite slow. this by any right is a huge, "forced" evolution. not in that we forced a change in the genetic code through editing it, but we are changing the course of genetics in a species through our collective behaviour).
natural selection, i.e. the environment they're born in, is what picks winners and losers among those inherited characteristics and mutations.
Almost all individual mutations on a genetic level are benign. It's the combination of (selection of specific trait + compounding change) that is what we know as evolution.
In this case, the "change to the genetic code" produces elephants without tusks. That happened by change. But now, the elephants without tusks are the ones who get to live, because they're not poached. That specific mutation allows them to live/thrive. In the same way better hearing might allow a bird to evade its predators.
"no change to genetic code" ignores the fact that there are elephants wandering around who don't have (and will never have) tusks. (also: evolution is quite slow. this by any right is a huge, "forced" evolution. not in that we forced a change in the genetic code through editing it, but we are changing the course of genetics in a species through our collective behaviour).
Evolution doesn't necessarily imply "new species" (species is actually a pretty vague term) and dictionary definitions are limited.
Try this resource instead: https://evolution.berkeley.edu/evolibrary/article/evo_01
Try this resource instead: https://evolution.berkeley.edu/evolibrary/article/evo_01
You don't have to change genes to change their presence in animals.
It's like market share. More users can simply download your software and you can gain market share without releasing an update.
It's like market share. More users can simply download your software and you can gain market share without releasing an update.
That's how it always is. It starts from somewhere and then somewhere along the line that fringe trait becomes desirable and then more widespread.
Like others said, it's evolution + natural selection. In this case the evolution part came long ago and now natural selection is making it more prevalent.
Like others said, it's evolution + natural selection. In this case the evolution part came long ago and now natural selection is making it more prevalent.
[deleted]
That's natural selection
it's selection, more precisely
change in genetics is not really evolution, it is just mutations. Evolution is environmental selection of advantageous mutations.
How can evolution know it has advantage. Do you see Human beings's actions or predicts?
And how can evolution know how it will change genetic code?
Evolution doesn't know anything. Tusked elephants are being killed, and the tuskless live on to breed.
The first figure of the paper they reference [0] has the numbers for this study:
-- 18.5% of females were tuskless before the war
-- 50.9% of females were tuskless after the war
-- 33% of females were tuskless in the first post-war generation
Of the offspring:
-- 8.7% of females born to two-tusked females were two-tusked
-- 44.7% of females born to tuskless females were tuskless
[0]: https://www.science.org/doi/10.1126/science.abe7389#F1
-- 18.5% of females were tuskless before the war
-- 50.9% of females were tuskless after the war
-- 33% of females were tuskless in the first post-war generation
Of the offspring:
-- 8.7% of females born to two-tusked females were two-tusked
-- 44.7% of females born to tuskless females were tuskless
[0]: https://www.science.org/doi/10.1126/science.abe7389#F1
Is anyone else surprised at how quick species can seem to evolve in these kinds of ways? Asian and African elephants are supposed to have separated millions of years ago, yet still strongly resemble one another. Yet in a few decades, something as fundamental as the presence of their tusks can shift dramatically. And that in a species with very long gaps between generations.
It makes me suspect there's something else going on here that's not just good old natural selection.
Have they done any tracking to confirm the tuskless elephants are actually being born to tuskless mothers? Or could it be that the parents are actually affecting the way their offspring are born in some lamarckian-esque sense? If there'd be some trick animals can pull to change their offspring in some ways, that ought to be highly effective for long term species survival and should thus be highly selected for.
It makes me suspect there's something else going on here that's not just good old natural selection.
Have they done any tracking to confirm the tuskless elephants are actually being born to tuskless mothers? Or could it be that the parents are actually affecting the way their offspring are born in some lamarckian-esque sense? If there'd be some trick animals can pull to change their offspring in some ways, that ought to be highly effective for long term species survival and should thus be highly selected for.
Nah, looks like natural selection. The article mentions that "The phenomenon of elephants going tuskless is not new. Researchers found the number of tuskless female elephants in Mozambique increased by almost double over 30 years. This overlaps with a period of civil conflict, where armed forces slaughtered 90% of the elephant population to produce ivory.". That is a LOT of selection pressure. Also, the African Elephant Specialist Group (AfESG) [1] published a graph of elephant populations, the reduction in total numbers is pretty dramatic. You might liken this to the way that humans in small, isolated communities will also start to differentiate in a hurry (forex, that one blue family).
[1] https://ourworldindata.org/grapher/african-elephants
[1] https://ourworldindata.org/grapher/african-elephants
I mean this honestly, but what is the blue family that you are talking about. The first thing that springs to mind is Avatar, and Google isn't helping me out.
A point evolution event can happen extremely rapidly if there's a clearly selective mortality event.
If a new predator is introduced to a population that selectively kills only certain traits, that mutation can become dominant in the population within just one or two generations.
Imagine if aliens came to Earth and killed everyone over 5'6" tall. That "evolution" would be essentially instantaneous.
If a new predator is introduced to a population that selectively kills only certain traits, that mutation can become dominant in the population within just one or two generations.
Imagine if aliens came to Earth and killed everyone over 5'6" tall. That "evolution" would be essentially instantaneous.
That evolution would still take multiple generations, since a 5'5 father and a 5'5 mother will have a 5'8 son on average.
Seems like the relative death rates of tusked vs tuskless would matter. Remember the 32% is a percent potentially on a small number. Say to an extreme 99% of tusked elephants were killed, 99% of tuskless were unharmed. If tuskless is a genetic traight, it takes over very quickly even though total population size is smaller.
Exactly that!
I think it is ridiculous to think that more elephant are born without tusks as a kind of "random selection" or even adaption
I think it is ridiculous to think that more elephant are born without tusks as a kind of "random selection" or even adaption
What do you mean by quick? Evolution is just random mutations. You're basically trying to diversify and spread risk. If there is huge selective pressure only a handful of genes will survive and when they reproduce they will be over represented compared to the previous generation.
As sad as this is, how does this kind of evolution happen?
I imagine the poaching process doesn't actually differentiate tusked and tuskless elephants, both types of elephants would fall into the trap and die? And then if it has tusks the poachers take them, if it doesn't have tusks the poachers just abandon the dead elephant?
Or does their trap actually trap them by the tusk?
I imagine the poaching process doesn't actually differentiate tusked and tuskless elephants, both types of elephants would fall into the trap and die? And then if it has tusks the poachers take them, if it doesn't have tusks the poachers just abandon the dead elephant?
Or does their trap actually trap them by the tusk?
They're hunted interactively by people with guns, not passively with traps.
Traps wouldn't work because the authorities would get to the elephant in a trap before the poacher returned, thus the poacher would lose their prey.
The poacher could always hang around near the trap, but if you're doing that you might as well just shoot the elephant, not trap it.
The poacher could always hang around near the trap, but if you're doing that you might as well just shoot the elephant, not trap it.
Yea I assume poachers shoot elephants, not trap them. So they only want to shoot ones with visible tusks.
Edit: I found an article[0] describing some poaching methods and apparently they do use traps! Including snares and a spiked board. But that it appears homemade shotguns and rifles are the most common method.
[0] http://www.open-earth.org/document/natureR_main.php?natureId...
Edit: I found an article[0] describing some poaching methods and apparently they do use traps! Including snares and a spiked board. But that it appears homemade shotguns and rifles are the most common method.
[0] http://www.open-earth.org/document/natureR_main.php?natureId...
Now I'm worried that in a couple hundred years a third of humans will have green eyes because all the blue ones have been harvested by aliens.
I had a couple of questions:
Are 100% of tusked females giving birth to 32% of the newborns without a tusk?
What % of tuskless females give birth to tusked females?
Are 100% of tusked females giving birth to 32% of the newborns without a tusk?
What % of tuskless females give birth to tusked females?
wait what? i didn’t realize my green eyes were rare. interesting and also that’s a huge jump from 2-4%, honestly at least we don’t have to worry about them going extinct, but still sad
Downvoted for weird statements about green eyes. If there is a back story include it in your comment.
What? They were just comparing the average rarity of the trait within a population. Literally googling "green eyes" would have given you the backstory: https://en.wikipedia.org/wiki/Eye_color#Green
Is this actually evolution or just selective breeding?
By killing elephants with tusks the poachers are favoring elephants with the no-tusk gene.
This isn't a lot different than killing a dog that bites sheep, which is how we bred herding dogs. Or a wolf that eats your baby, which is how we domesticated dogs.
This trait already existed so it certainly wasn't "engineered due to mass poaching for ivory" as claimed.
By killing elephants with tusks the poachers are favoring elephants with the no-tusk gene.
This isn't a lot different than killing a dog that bites sheep, which is how we bred herding dogs. Or a wolf that eats your baby, which is how we domesticated dogs.
This trait already existed so it certainly wasn't "engineered due to mass poaching for ivory" as claimed.
Evolution IS selective breeding. The members of a species most fit for their environment are successful in procreation. The female elephants without tusks are surviving at higher rates which is resulting in more offspring with no tusks. This causes a shift in the population where a trait previously with no or little benefit becomes advantageous and the shift in genetic makeup of the whole population evolves.
But we don't commonly run around saying Arabians and Morgans are different because of evolution. Neither do we say that chihuahua's and labradors have evolved into their present form.
In my humble opinion "evolution" refers to speciation, which takes very many generations.
In my humble opinion "evolution" refers to speciation, which takes very many generations.
The distinction between one species and another is pretty arbitrary in many cases. Exact species boundaries, or even the concept of "species" itself, are something humans determine, by convention. Evolution is something that happens regardless.
> Evolution is defined as the change in the inherited traits of a population of organisms through successive generations… When particular genetic sequences change in a population (e.g., via mutation) and these changes are inherited across successive generations, this is the stuff of evolution… One can distinguish between two general classes of evolutionary change: microevolution (change below the level of the species) and macroevolution (change above the level of the species)… These [micro-evolutionary] processes can, but do not necessarily, lead to the formation of new species over time but instead result in fluctuating frequencies of traits within populations tracking ever-changing selective pressures.
https://www.nature.com/scitable/knowledge/library/evolution-...
> Evolution is defined as the change in the inherited traits of a population of organisms through successive generations… When particular genetic sequences change in a population (e.g., via mutation) and these changes are inherited across successive generations, this is the stuff of evolution… One can distinguish between two general classes of evolutionary change: microevolution (change below the level of the species) and macroevolution (change above the level of the species)… These [micro-evolutionary] processes can, but do not necessarily, lead to the formation of new species over time but instead result in fluctuating frequencies of traits within populations tracking ever-changing selective pressures.
https://www.nature.com/scitable/knowledge/library/evolution-...
Thanks for the thoughtful response. Good link.
So in this case, evolution is the correct term. Microevolution is more correct.
Macroevolution is more correct when describing speciation.
So in this case, evolution is the correct term. Microevolution is more correct.
Macroevolution is more correct when describing speciation.
We already have a term for speciation though. Evolution is more broad.
> Neither do we say that chihuahua's and labradors have evolved into their present form.
This is artificial selection. When it occurs naturally, it's called Natural selection & it's the basis of evolution. The mechanism of both artificial and natural selection is the same -- increase of a trait in the population by selecting only animals with that trait to reproduce. Speciation is merely a result of this process.
Btw the pulitzer winning book "The beak of the finch" discusses how evolution actually doesn't need many generations to happen. What it needs is selection pressure -- events (such as severe draught) that force natural selection to happen within a handful of generations. It's a fascinating book on a fascinating study.
This is artificial selection. When it occurs naturally, it's called Natural selection & it's the basis of evolution. The mechanism of both artificial and natural selection is the same -- increase of a trait in the population by selecting only animals with that trait to reproduce. Speciation is merely a result of this process.
Btw the pulitzer winning book "The beak of the finch" discusses how evolution actually doesn't need many generations to happen. What it needs is selection pressure -- events (such as severe draught) that force natural selection to happen within a handful of generations. It's a fascinating book on a fascinating study.
It’s just selective evolution. We just use a different word for it to convey more information. It’s the same process though albeit randomly.
> Neither do we say that chihuahua's and labradors have evolved into their present form.
They 'evolved' into their present forms because they were forced/accelerated by the hand of humans through selective breeding.
They 'evolved' into their present forms because they were forced/accelerated by the hand of humans through selective breeding.
Selective breeding is an important component of evolution. But evolution is certainly not just selective breeding. Population diversity whether it's through random chance, genetic drift, horizontal transfer etc. is also a key component of evolution. Equating evolution with just selective breeding is incorrect.
For what it's worth, he could have said "Selective breeding IS evolution" and his comment would read the same. The point is that selective breeding is a subset of evolution, so attempting to ask, "Isn't this just selective breeding?" would be answered with a, "No, because selective breeding is a subset of evolution."
"Is this a rectangle or just a square?" "A square IS a rectangle."
"Is this a rectangle or just a square?" "A square IS a rectangle."
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Humans exerting selective pressure are also part of nature, so I guess this is evolution.
"Selective breeding" is a term used when humans engineer species on purpose. In this case it's the opposite actually, elephants are adapting to survive poachers. Selective breeding would be if poachers started raising tusked elephants in farms.
"Selective breeding" is a term used when humans engineer species on purpose. In this case it's the opposite actually, elephants are adapting to survive poachers. Selective breeding would be if poachers started raising tusked elephants in farms.
Selective breeding is one form of evolution.
The only distinction is really that selective breeding is intentional - which is not the case here.
Was it "selective breeding" when MRSA arose due to our use of antibiotics?
Was it "selective breeding" when MRSA arose due to our use of antibiotics?
Tuskless elephants probably due to hunting have a better chance of passing their genes.
Which makes it eligible for "Natural Selection"
Which makes it eligible for "Natural Selection"
Cool side story is the American tech millionaire who has dedicated his life and fortune to the recovery of Gorongosa National Park.
https://en.wikipedia.org/wiki/Gregory_C._Carr
https://gorongosa.org/greg-carr/
https://en.wikipedia.org/wiki/Gregory_C._Carr
https://gorongosa.org/greg-carr/
That's really inspiring, I'd love to do something similar if/when I'm more financially free. Got any other examples of people doing similar things? We definitely need more people doing this, rather than trying to get to space.
What if unicorns at one point existed, but were hunted for the superstitious power of their horns, leaving only the hornless to reproduce and eventually eliminate the gene? How would we know?
There are plenty of horses and horse-ancestors in the fossil record. We would at least expect to see some horn material preserved. Failing that, there would be evidence on the skull itself due to how the attachment of the horn would leave evidence of its existence on the bone of the skull. You would probably also expect to see some horns in archaeological caches. I know they sometimes find narwhal tusks in burial sites.
Interestingly enough, there was a creature that very much looks like a unicorn, but it is a rhinoceros and not an equine.
https://en.wikipedia.org/wiki/Elasmotherium
Interestingly enough, there was a creature that very much looks like a unicorn, but it is a rhinoceros and not an equine.
https://en.wikipedia.org/wiki/Elasmotherium
There's also no cultural record of legends of "unicorn hunts" unlike say hunting the white stag.
There are plenty of stories of unicorns, though. Why them and not some other animal?
There are plenty of stories of dragons, too.
So why are there so many stories of dragons, even across cultures that had little to no contact whatsoever?
There's a very interesting (but somewhat contrived) anthropological hypothesis that dragons are composites of various predator creatures that were a danger to our ancestors- birds of prey, great cats, and pythons:
https://en.wikipedia.org/wiki/An_Instinct_for_Dragons
https://en.wikipedia.org/wiki/An_Instinct_for_Dragons
As a kid being taught evolution, I made the natural assumption that many transitional forms of animals would be found in the fossil record in order to support the theory. However that is not the case(to put it mildly). When confronted with this fact, "scientists" created a new theory called punctuated equilibrium. what a house of cards..
Right because science just wants to ruin the fun and imaginations of young children - that's its only function, right?
On the topic of unicorns existing...
> There are wild elephants in the country, and numerous unicorns, which are very nearly as big. They have hair like that of a buffalo, feet like those of an elephant, and a horn in the middle of the forehead, which is black and very thick. They do no mischief, however, with the horn, but with the tongue alone; for this is covered all over with long and strong prickles and when savage with any one they crush him under their knees and then rasp him with their tongue. The head resembles that of a wild boar, and they carry it ever bent towards the ground. They delight much to abide in mire and mud. 'Tis a passing ugly beast to look upon, and is not in the least like that which our stories tell of as being caught in the lap of a virgin; in fact, 'tis altogether different from what we fancied
- Macro Polo
https://en.wikisource.org/wiki/The_Travels_of_Marco_Polo/Boo...
They're hunted for their horns too...
https://en.wikipedia.org/wiki/Rhinoceros#Ways_to_prevent_poa...
> There are wild elephants in the country, and numerous unicorns, which are very nearly as big. They have hair like that of a buffalo, feet like those of an elephant, and a horn in the middle of the forehead, which is black and very thick. They do no mischief, however, with the horn, but with the tongue alone; for this is covered all over with long and strong prickles and when savage with any one they crush him under their knees and then rasp him with their tongue. The head resembles that of a wild boar, and they carry it ever bent towards the ground. They delight much to abide in mire and mud. 'Tis a passing ugly beast to look upon, and is not in the least like that which our stories tell of as being caught in the lap of a virgin; in fact, 'tis altogether different from what we fancied
- Macro Polo
https://en.wikisource.org/wiki/The_Travels_of_Marco_Polo/Boo...
They're hunted for their horns too...
https://en.wikipedia.org/wiki/Rhinoceros#Ways_to_prevent_poa...
I think we'd expect to see vestiges of the no-longer-outwardly-visible horn in the skeleton and perhaps during fetal development, like with human tails.
The fossil record.
If they were hunted then there might be a cultural record as well.
If they were hunted then there might be a cultural record as well.
There is anthropological work claiming that unicorns were actually a mis-depiction of the single horn rhinoceros.
No. They evolved to become fat and became rhinoceros
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Unicorns don't exist because they were arrogrant, unserious creatures who refused to fall in line with the other animals:
Source: https://www.google.com/search?q=shel+silverstein+unicorn
Source: https://www.google.com/search?q=shel+silverstein+unicorn
Interesting, are there any Rhino mutations without horns? Conservationists are cutting Rhino's horn, in an effort to safe them from poachers, but poachers kill them anyway, because of the horn stub that is left. https://www.savetherhino.org/thorny-issues/de-horning/
Honest question from someone who knows virtually nothing about chemistry or material science: is there a difference in quality between synthetic and natural ivory? If not, why is poaching even still a viable market?
This will probably be downvoted but the reality is it's because there's a ton of new money in China where they're still valuing things like Ivory culturally. There's no cultural stigma at this point. The government has banned it but the black market trade is still strong. See shark fin soup as another example.
Also if you buy the offical story of Covid it is this desire for exotic expensive animals with questionable natural medical benefits that caused the zootopic jump of Covid from bats to humans. So the real cost of this sort of trade now couldnt be higher.
Most virologists buy what you call the "official story", for what it's worth.
It isnt worth much, there is no physical evidence to support either theory, lab leak or wet market. We just have to take the word of a communist regeime, "there is no graphite on the roof" comes to mind.
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Superstition. Elephants and tigers are not hunted for inherent qualities of their bodies, but for the belief that consumption of their parts in various ways helps health/virility/...
Superstition really seems to be one of the largest factor when it comes to animal hunting/consumption. It's ridiculous and a little bit ironic that something supposedly to bring good fortune will result in wide scale killing of animals, living earthlings.
>"It's ridiculous and a little bit ironic that something supposedly to bring good fortune will result in wide scale killing of animals, living earthlings."
How is this ironic? Most cultures have prized animal products throughout recorded history, and many have practiced sacrifices, which is literally the killing of the being.
How is this ironic? Most cultures have prized animal products throughout recorded history, and many have practiced sacrifices, which is literally the killing of the being.
Not the parent, but the irony is that to bring good fortune, you bring incredible misfortune (extinction, even) upon other living things.
It seems like the comment I responded to was referring to something like an 'incongruity', and saying it was '[situational] irony', but it doesn't really satisfy the definition of situational irony (from wikipedia):
>"Situational irony: The disparity of intention and result; when the result of an action is contrary to the desired or expected effect."
In this specific case, the intention of extracting animal products caused the animals to be killed, which is not contrary to the expected effect (unfortunate as it may be).
>"Situational irony: The disparity of intention and result; when the result of an action is contrary to the desired or expected effect."
In this specific case, the intention of extracting animal products caused the animals to be killed, which is not contrary to the expected effect (unfortunate as it may be).
Okay, lets give context of irony, Elephants are hunted for their amazing mystical power to bring good fortune to humans who posses their tusks.
Now lets imagine the elephants actually provide a long distant benefit to humans, butterfly effect style. Maybe their migration involves knocking over some dormant trees with their tusks, which they're known to do, that would then knock over seeds for new trees. This would aid in the containment of soil and prevent soil erosion.
Instead, consider they're all gone, the trees all die off without seeding, then windstorms etc turn more land into desert.
Ironically those same hunters now have less land to grow food from. Thus less fortune, the action to bring more fortune has resulted in less.
This is a stretch of an example using just 1 animal, but whats more confusing is why it needed to be defined through the purview of defining ironic.
Edit: As mentioned this is 1 example, but there are an uncountable scenarios of 'medicinal' practices that require the 'rarest' animal components to 'work' from. Point is, its all superstition and it contributes far too much.
Now lets imagine the elephants actually provide a long distant benefit to humans, butterfly effect style. Maybe their migration involves knocking over some dormant trees with their tusks, which they're known to do, that would then knock over seeds for new trees. This would aid in the containment of soil and prevent soil erosion.
Instead, consider they're all gone, the trees all die off without seeding, then windstorms etc turn more land into desert.
Ironically those same hunters now have less land to grow food from. Thus less fortune, the action to bring more fortune has resulted in less.
This is a stretch of an example using just 1 animal, but whats more confusing is why it needed to be defined through the purview of defining ironic.
Edit: As mentioned this is 1 example, but there are an uncountable scenarios of 'medicinal' practices that require the 'rarest' animal components to 'work' from. Point is, its all superstition and it contributes far too much.
See my below comment - but no 'incongruity' is something completely different to irony.
Taking it a step further, the "value" of a sacrifice depends on how precious the thing is that you are sacrificing. Sacrificing a mouse is not the same as sacrificing a healthy goat.
[deleted]
It brings good fortune to the humans, not the animals.
Has Viagra not reached China yet?
Sure, but if they bleach it white and sell it as powder under some "Ivory" branding that will just increase poaching.
Ultimately, a good number of people will want "the real thing", even if it is virtually identical. There are plenty of people who think lab grown diamonds are illegitimate, despite having the exact same chemical composition as mined diamonds. For the rich and powerful, the Ivory is more important as a status symbol than anything else. Synthetic Ivory is effectively useless as a signal.
Plus, there are people out there who sincerely believe that Ivory works as an ingredient in medicine and they will seek it out.
Plus, there are people out there who sincerely believe that Ivory works as an ingredient in medicine and they will seek it out.
Synthetic ivory is great as a signal if it's indistinguishable and you lie about it's origins.
But a lot of people want to/need-to "signal themselves".
Which reminds me, I'm not sure why cops don't try to move fake ivory into black markets, have sting operations where once they catch a dealer, instead of arresting them, force them to sell their fake ivory, undercut the market enough that poachers have incentive.
Probably China isn't that concerned about the problem.
But a lot of people want to/need-to "signal themselves".
Which reminds me, I'm not sure why cops don't try to move fake ivory into black markets, have sting operations where once they catch a dealer, instead of arresting them, force them to sell their fake ivory, undercut the market enough that poachers have incentive.
Probably China isn't that concerned about the problem.
Unfortunately (even ignoring chemistry/matsci), one of the answers to that is simply "natural ivory is becoming a scarce resource". When something is scarce, it becomes sought after, which can result in it even becoming a Veblen Good[1] over time.
[1] https://www.investopedia.com/terms/v/veblen-good.asp
[1] https://www.investopedia.com/terms/v/veblen-good.asp
I imagine people view it similarly to leathers made from animal hides to synthetic materials. Synthetics may be better in some ways but people are in-part attracted by the character or feel that the imperfections of a natural material provide.
Leather from animal and leather from plastic is extremely different. It’s not just the imperfection, it doesn’t stretch the same way and the composition is fundamentally different
Synthetic ivory is ivory.
Synthetic ivory is ivory.
McDonald's chicken nuggets aren't perfect ovaloids. They have artificial imperfections that people enjoy. (There are 4 different molds.)
You don't need natural imperfections.
You don't need natural imperfections.
Isn't synthetic leather prone to flaking?
as an amateur pianist, I've played pianos with and without ivory keys, and the feel of ivory is a bit better. I'm not sure why, but it seems like it doesn't get as slick from sweat as you play. Of course, piano keys are not the cause of current ivory demand to the best of my knowledge, and I'll happily take non-ivory keys.
Piano makers have not used real Ivory in many years. There is a market for used ivory on pianos, but that is only to repair antique pianos. Piano makes/owners have been careful about this for long enough that pianos with real ivory get a pass because everyone understands they are dealing only with ivory from before we knew better.
Is that comparing ivory wth plastic keys, or ivory with some synthetic version of ivory?
could it be because ivory is porous, wicking away the moisture?
When you have over a billion people in a culture valuing ivory, it doesn't take a large percentage of holdouts/morons/assholes/psychopaths to pose an existential threat to Elephants.
Multiplication is a bitch.
Multiplication is a bitch.
> Researchers found the number of tuskless female elephants in Mozambique increased by almost double over 30 years. This overlaps with a period of civil conflict, where armed forces slaughtered 90% of the elephant population to produce ivory. This ivory went on to finance the conflict.
People suck.
People suck.
The civil war and conflict was created by white colonizers and CIA (America):
https://www.africanexponent.com/post/4981-civil-war-in-mozam...
https://www.africanexponent.com/post/4981-civil-war-in-mozam...
Whilst I agree that this was a proxy in the cold war and that Colonial history messed up Africa big time, I don't understand what you are trying to say here?
He's saying that it's not a case of "oh, silly uncivilised African warlords", but rather, "look at another underhanded neo-liberal operation that destabilised a region".
The good thing is that humanity's days are numbered.
All the planet needs is the short incoming fever.
All the planet needs is the short incoming fever.
Do you think anything else may have happened over the course of 30 years that may influence demand for ivory?
nice generalisation. i for once never thought even remotely about slaughtering a freaking elephant in order to get the tusks.
yes lots of people are bad and do bad things , but that does not mean that all people suck.
#NotAllPeople
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A lot of elephants are killed for the ivory in their tusks
Some elephants are born without tusks and live much longer.
Natural mating between tuskless elephants will dramatically increase.
This will result in the trait being propagated rapidly.
Some elephants are born without tusks and live much longer.
Natural mating between tuskless elephants will dramatically increase.
This will result in the trait being propagated rapidly.
>This will result in the trait being propagated rapidly.
Another comment by Stevvo mentioned
> ... a trait that could negatively impact a female's chance of survival AND kills 100% of her male offspring.
Another comment by Stevvo mentioned
> ... a trait that could negatively impact a female's chance of survival AND kills 100% of her male offspring.
At the risk of being downvoted to oblivion, is there such thing as ethicially sourced ivory?
If not, I imagine the only reasonable thing to do would be to educate and raise awareness on the catastrophic impact poaching has on the elephant species as a whole.
If not, I imagine the only reasonable thing to do would be to educate and raise awareness on the catastrophic impact poaching has on the elephant species as a whole.
This is a fantastic question - as this is indeed done for other African animals, like crocodiles.
The biggest issue is that elephants cannot be profitably raised in captivity - they require too much food, too much space, and take too long to produce tusks.
...and if you allow them to roam in reserves, then poachers shoot them. I do wonder if it might work in another part of the world that could offer better security for large elephant reserves, without them impacting the native habitat.
It has also been tried with tusks obtained by elephants that naturally died, and that program failed due to smugglers bribing officials to insert poached ivory into the auctions [0].
[0] https://www.washingtonpost.com/news/energy-environment/wp/20...
I think the underlying issue is that demand is so high that there wouldn't be anywhere on Earth that could produce enough to stop cheap poaching in Africa, so it's easier to simply ban the trade entirely.
Maybe there's an opportunity for lab-grown ivory? [1]
[1] https://cen.acs.org/articles/96/i4/synthetic-horns-tusks-off...
The biggest issue is that elephants cannot be profitably raised in captivity - they require too much food, too much space, and take too long to produce tusks.
...and if you allow them to roam in reserves, then poachers shoot them. I do wonder if it might work in another part of the world that could offer better security for large elephant reserves, without them impacting the native habitat.
It has also been tried with tusks obtained by elephants that naturally died, and that program failed due to smugglers bribing officials to insert poached ivory into the auctions [0].
[0] https://www.washingtonpost.com/news/energy-environment/wp/20...
I think the underlying issue is that demand is so high that there wouldn't be anywhere on Earth that could produce enough to stop cheap poaching in Africa, so it's easier to simply ban the trade entirely.
Maybe there's an opportunity for lab-grown ivory? [1]
[1] https://cen.acs.org/articles/96/i4/synthetic-horns-tusks-off...
You cannot grow them as a business model, however if you already have a preserve and elephants on them wouldn't a) be safer to remove the tusks from the elephants to make them less of a target and b) sell the removed tusks to fund your preserve ?
The moment anyone in the world starts selling tusks, poachers start shooting elephants and smuggling the tusks into these "legal" markets/auctions.
Fun Fact: Violin bows also contain ivory in the tip.
https://www.benningviolins.com/ivory-violins-and-violin-bows...
I had a friend who was a luthier, and in this tradition the father hands over the materials to the son, so that you may have wood that's been aging for 40 years, and a stockpile of ivory to use in the bows.
https://www.benningviolins.com/ivory-violins-and-violin-bows...
I had a friend who was a luthier, and in this tradition the father hands over the materials to the son, so that you may have wood that's been aging for 40 years, and a stockpile of ivory to use in the bows.
It depends on your owns consideration of what is ethic : some animist may not consider ethic to take part off a dead corpse. Others may draw the line between wild and bred animals. You may also consider that it is ethic to kill a living being if you do it in an « honorable » way (use your own definition of honorable) , as in coridas or hunting.
Great plan, but I'm pretty sure that people who buy ivory don't give a damn about elephants.
I remember reading about the very thing, sold by one of the wildlife reserves, coming only from naturally deceased animals.
There's also other species that have comparable bones. Supposedly, the melting permafrost is drowning the ivory market with mammoth ivory (which somehow is a cheap counterfeit, not an awesome curiosity): https://www.wired.co.uk/article/mammoth-tusk-hunters-russia-...
There's also other species that have comparable bones. Supposedly, the melting permafrost is drowning the ivory market with mammoth ivory (which somehow is a cheap counterfeit, not an awesome curiosity): https://www.wired.co.uk/article/mammoth-tusk-hunters-russia-...
Injection-molded plastic?
I kid. I kid. Obviously, injection-molded plastic is bad for the environment, regardless of its history as an "ethical source of ivory."
I kid. I kid. Obviously, injection-molded plastic is bad for the environment, regardless of its history as an "ethical source of ivory."
With discussions around evolution, I try to keep in mind that the main pressure for evolution is from natural selection, and natural selection works on death. Plenty of species have been "naturally selected" for total extermination.
It's difficult to keep ethics out of discussions when facing the reality of life: that there is a massive amount of death and suffering, and it's a terrifying thing we're all forced into, including these elephants.
It's difficult to keep ethics out of discussions when facing the reality of life: that there is a massive amount of death and suffering, and it's a terrifying thing we're all forced into, including these elephants.
Makes me wonder how human activity is evolving our very own genetic pool. Examples: competition vs cooperation, male vs female height, our immune system.
We have long had a culture where men prefer mates that are shorter than them, and women prefer mates that are taller. This results in constant pressure on the pool resulting in men being on average taller than women. Will this change over time as we outgrow this rather primitive preference? (Sadly, even many feminist women have clung to this preference.) Not all species "prefer" that the male is bigger or stronger than the female.
An obvious one is our reliance on modern medical technology, and drugs in particular. Are our bodies becoming less able to fend off disease?
The most important one for me is the balance between those genes that give us our selfishness and those that give us empathy and love. What impact does an ever more individualistic culture and an economic system that defines selfishness as a virtue have on our gene pool?
We have long had a culture where men prefer mates that are shorter than them, and women prefer mates that are taller. This results in constant pressure on the pool resulting in men being on average taller than women. Will this change over time as we outgrow this rather primitive preference? (Sadly, even many feminist women have clung to this preference.) Not all species "prefer" that the male is bigger or stronger than the female.
An obvious one is our reliance on modern medical technology, and drugs in particular. Are our bodies becoming less able to fend off disease?
The most important one for me is the balance between those genes that give us our selfishness and those that give us empathy and love. What impact does an ever more individualistic culture and an economic system that defines selfishness as a virtue have on our gene pool?
This reminds me of this study that polled academics and students about the evolutive process that happens. The results are quite decieving. https://journals.openedition.org/ress/2698
For those who don't want to read a long French article: the conclusion (as I understood it) is that most people imagine teleological, or goal-driven (the authors describe it as "finalist") reasons for this very change in tusks. That is, even when the subjects consider that poaching may be the cause in the change in tusk allele frequency, they say it's because the elephants "want" not to have tusks, or that evolution is "deliberately" evolving away from tusks in order to protect the elephants.
This is in contrast to the actual explanation, which is simply that if you kill the elephants with the tusks alleles and prevent them from breeding, you'll have fewer of those alleles in the subsequent generations.
I'd say this result is not so "deceiving," as someone who has prepared evolution curriculum in the past, the teleological explanation is extremely seductive, even for educated people.
This is in contrast to the actual explanation, which is simply that if you kill the elephants with the tusks alleles and prevent them from breeding, you'll have fewer of those alleles in the subsequent generations.
I'd say this result is not so "deceiving," as someone who has prepared evolution curriculum in the past, the teleological explanation is extremely seductive, even for educated people.
Elephants are not "evolving" and it's not a "response" to poaching! Poachers killed elephants with tusks, and as a consequence elephants without tusks have a reproductive advantage.
This is more like dog breeding than about nature fighting back.
This is more like dog breeding than about nature fighting back.
> Poachers killed elephants with tusks, and as a consequence elephants without tusks have a reproductive advantage.
Yes, this is natural selection, the process through which evolution happens.
Yes, this is natural selection, the process through which evolution happens.
Disagreed. This really is natural selection and not artificial selection.
The poachers aren't selectively breeding for elephants without tusks. Quite the opposite. You are correct that it's a tautology - the elephants remaining are the ones without tusks - but that's exactly how natural selection works.
The poachers aren't selectively breeding for elephants without tusks. Quite the opposite. You are correct that it's a tautology - the elephants remaining are the ones without tusks - but that's exactly how natural selection works.
> The poachers aren't selectively breeding for elephants without tusks
Yes they are, that is exactly what they are doing.
There is nothing natural about it. It wouldn't happen if not for the poachers.
Yes they are, that is exactly what they are doing.
There is nothing natural about it. It wouldn't happen if not for the poachers.
But the poachers would rather breed for elephants with tusks, that's the whole point of their poaching after all.
I feel like I don't really know enough about the specifics of natural selection or evolution to have a strong opinion on this.
The poaching is definitely not natural, so it feels like this is not natural selection.
On the other hand, no one is deliberately breeding for this in any way, it's purely a side effect of these circumstances, which does feel more natural.
You could just view the poachers as an environmental hazard to tusked elephants, in which case this would be a perfect example of natural selection.
I feel like I don't really know enough about the specifics of natural selection or evolution to have a strong opinion on this.
The poaching is definitely not natural, so it feels like this is not natural selection.
On the other hand, no one is deliberately breeding for this in any way, it's purely a side effect of these circumstances, which does feel more natural.
You could just view the poachers as an environmental hazard to tusked elephants, in which case this would be a perfect example of natural selection.
> You could just view the poachers as an environmental hazard to tusked elephants, in which case this would be a perfect example of natural selection.
Yes okay you can say this...
But if you are saying that poachers/humans are part of nature, then nothing in the world is "unnatural" anymore. I think this line of reasoning, while valid, is less precise and less interesting.
Yes okay you can say this...
But if you are saying that poachers/humans are part of nature, then nothing in the world is "unnatural" anymore. I think this line of reasoning, while valid, is less precise and less interesting.
A distinction without a difference.
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Not sure about the linked article, but the paper was also mentioned in last week The Economist, and it said that the number of tusk-less elephants was already dropping (it peaked 50% and now is 33%) due to conservation efforts.
Has anyone tried raising elephants using industrial livestock methods, for harvesting ivory and reducing the price to reduce poaching?
I expect that selective breeding could yield elephants that produce large amounts of ivory continuously. Elephant generation time is a minimum of 11 years (2 years gestation and 9 years for females to reach sexual maturity). The project would take many years.
Other animals produce ivory. Common warthog has a 2-year generation time. Hippo is 7 years. Walrus is 6 years. Narwhal is 7 years.
I expect that selective breeding could yield elephants that produce large amounts of ivory continuously. Elephant generation time is a minimum of 11 years (2 years gestation and 9 years for females to reach sexual maturity). The project would take many years.
Other animals produce ivory. Common warthog has a 2-year generation time. Hippo is 7 years. Walrus is 6 years. Narwhal is 7 years.
In the Science article they wrote, “Poaching resulted in strong selection that favored tusklessness amid a rapid population decline.” And, “Whole-genome scans implicated two candidate genes with known roles in mammalian tooth development (AMELX and MEP1a), including the formation of enamel, dentin, cementum, and the periodontium.”
So, there was a change in the genes, but how do they connect this fact with poaching? I don’t see the relation. Surely, elephants themselves, cannot decide to change their genetics as a reaction to poaching.
So, there was a change in the genes, but how do they connect this fact with poaching? I don’t see the relation. Surely, elephants themselves, cannot decide to change their genetics as a reaction to poaching.
It's not like evolution detects this. If you kill off all the blond headed people in town, all the babies next year will be born with brown hair. The tuskless variant was already in the population at some proportion, but due to tusks being a target of poaching, those that carry the tuskless variant are more likely to survive and have offspring, who are also going to have this tuskless variant. Over time, the population will shift and this tuskless variant will be present at a higher proportion in the overall population.
> If you kill off all the blond headed people in town, all the babies next year will be born with brown hair.
The blond hair allele is recessive and can be hidden. Two brown-haired parents can have a blond child.
The blond hair allele is recessive and can be hidden. Two brown-haired parents can have a blond child.
> how do they connect this fact with poaching?
Poachers kill elephants for their tusks. A poacher won't kill an elephant with partially formed or no tusks, as it has no value to them. This allows elephants with the tuskless gene to survive and eventually reproduce where other elephants would not.
Poachers kill elephants for their tusks. A poacher won't kill an elephant with partially formed or no tusks, as it has no value to them. This allows elephants with the tuskless gene to survive and eventually reproduce where other elephants would not.
It's artificial* selection. The ones with husks die** more often before having offsprings, or will on average get to have fewer offsprings, in comparison to the tuskless individuals.
*) Humans are putting the pressure.
**) Are killed by poachers.
*) Humans are putting the pressure.
**) Are killed by poachers.
Evolution works thanks to natural pressures -- in this case, a mutation in the gene gives an elephant no tusks, and thanks to this they are not killed by poachers. That elephant is lucky enough to survive to pass on its DNA. The recessive gene, over many generations, grows more dominant as more and more elephants "benefit" from having no tusks by not being hunted.
So the elephants aren't reacting to poaching -- the "reaction" is a random mutation that happens to align with external pressures, causing a shift in genetics for the population.
So the elephants aren't reacting to poaching -- the "reaction" is a random mutation that happens to align with external pressures, causing a shift in genetics for the population.
Random mutations happen all the time. If there’s selection pressure that favors a given mutation, it will proliferate.
Just throwing it out there; i know it's scientifically accepted that genetic mutations are simply random and the ones that just so happen to be helpful are propagated by natural selection, but i sometimes wonder that 'random' is a word akin to 'magic' that describes a process we do not quite understand. Specifically in the context of evolution, i wonder if genetic mutations aren't as random as we believe it to be, but that life is more 'intelligent' than we give it credit for, and mutations are, if not always at least sometimes, an intentional response to changes in their environment. I'd be very interested to see more research in the way that genetic mutations may be influenced by external stimuli.
Not an idea i deeply hold as a truth, but fun to think about, and science doesn't expand by believing we've got it all figured out.
Not an idea i deeply hold as a truth, but fun to think about, and science doesn't expand by believing we've got it all figured out.
Surely? I wouldn't discount the power of intention when applied to the all too common occurrence of deep emotional stress of experiencing the loss of your family in such a violent display.
I would like to see numbrs for elephant population, considering this study takes into consideration 30 years of heavy poaching and average life of african elephant is at least 60-70 years, couldn't this be just smaller sample group? so obviously if you kill 90% of elephants and leave only 10%, most of them tuskless, their offsprings will be much more commonly tuskless, though it doesn't mean it won't return back by itself over time
> Published in Science on Thursday, the study looked at the genetic changes engineered due to mass poaching for ivory.
This interpretation of evolution is a myth that needs to be busted. Nothing is being "engineered". What is happening is simply: no tusks is an advantage. That is, no tusks means less likely to be hunted / killed.
As a result, the tusk genes in the gene pool are less available. The no-tusks genes more.
In short, and ultra-simplified, evolution is reactive.
This interpretation of evolution is a myth that needs to be busted. Nothing is being "engineered". What is happening is simply: no tusks is an advantage. That is, no tusks means less likely to be hunted / killed.
As a result, the tusk genes in the gene pool are less available. The no-tusks genes more.
In short, and ultra-simplified, evolution is reactive.
Is this how evolution works? The article implies a cause and effect. But i always thought genetic variation was random and if that variation conferred some advantage in the world, it would dominate over many 1000s of years.
Also, i imagine elephants have long gestation periods and live longer than say your average single cell organism. Meaning the "evolution cycle" if you will, is much more drawn out..
Also, i imagine elephants have long gestation periods and live longer than say your average single cell organism. Meaning the "evolution cycle" if you will, is much more drawn out..
> Relentless ivory hunting over decades has caused elephants to evolve in a way we never imagined them to.
This is only true if "we" have very little imagination.
This is only true if "we" have very little imagination.
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Poaching and hunting play a part in this one as they slowly eliminate elephants with tusks. Thus, huskless elephants are mating with each other—results in the birth of huskless elephants.
At least 6 threads here claiming selective breeding is really just evolution and it is a semantic issue. Would any experts please step up and clarify this?
Evolution is in general very slow when it comes to animals. I have my doubts if poaching is the true cause or if there is some environmental reason.
Evolution needn't be slow. We've evolved (via unnatural selection) chickens over just a few decades to have more and more white breast meat, to the point where they can't stand up on their own. We've rapidly evolved dog breeds to have characteristics we covet.
If there was a deadly virus that killed human that do not have blue eyes, the entire human population would "evolve" to having blue eyes very quickly.
This is exactly what happened with the tusk-less elephants.
This is exactly what happened with the tusk-less elephants.
Some eye colors are dominant. We still have a lot of different eye colors.
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Yes, that's why in my example I chose to keep alive only the most recessive eye color (both brown and green dominate blue).
Because the ones with tusks are being removed from pool (killed) before they can reproduce. Therefore their genes are not replicated and that characteristic goes away.
It’s more selection than “evolution” but they work together.
It’s more selection than “evolution” but they work together.
The article is explicit that it's an environmental pressure selecting for a previously recessive trait, similarly to Peppered moths during the Industrial Revolution[1].
[1]: https://en.wikipedia.org/wiki/Peppered_moth_evolution
[1]: https://en.wikipedia.org/wiki/Peppered_moth_evolution
I think that in this case it might just be a case of 'selective breeding' rather than 'evolution' sensu stricto.
Those with large tusks are shot dead and thus only tuskless remain. Not much different with breeding dogs for specific traits which is way faster process than evolution to adapt a species to the environment
Those with large tusks are shot dead and thus only tuskless remain. Not much different with breeding dogs for specific traits which is way faster process than evolution to adapt a species to the environment
Evolution is slow when humans aren't a involved. Most poachers kill the elephants for the tusks. This is artificial selection, similar to dog breeding, which is different from natural selection.
Humans or no, environments can change quickly and drastically, causing certain genetic characteristics to quickly become favored for survival and reproduction. Evolution is all about generational adaptation to changing environments. When the environment changes quickly, evolution can happen quickly. Populations simply disappear if the necessary adaptations cannot occur quickly enough.
https://www.sciencedaily.com/releases/2013/04/130409095414.h...
https://www.discovermagazine.com/the-sciences/rapid-evolutio...
https://www.sciencedaily.com/releases/2013/04/130409095414.h...
https://www.discovermagazine.com/the-sciences/rapid-evolutio...
This could be better defined as breeding for specific traits.
Elephants without tusks are the ones “allowed” to breed.
Elephants without tusks are the ones “allowed” to breed.
Sounds like the poachers are scientists now.
Do they meticulously record their data? Checkmate.
Selection at work. I speculate that fish size is undergoing similar effect due to fishing-net eye-sizes.
If humans can modify the animals in the environment this fast, I see no reason why we just cannot assume that most of the living wild animals are already a result of humans doing the selection.
I was always quite confused by the fact that most animals look quite nice but given these results I guess humans can extinguish the ugly and leave the beautiful.
I was always quite confused by the fact that most animals look quite nice but given these results I guess humans can extinguish the ugly and leave the beautiful.
I wonder how long tusk vs non tusked females live in a poachfree environment.
While sad as a whole, the responsiveness of evolution is beautiful in this case.
It also demonstrates that human efforts to stop poaching have not been successful (otherwise this evolution wouldn’t happen), but luckily, nature responds.
It also demonstrates that human efforts to stop poaching have not been successful (otherwise this evolution wouldn’t happen), but luckily, nature responds.
Not sure 'beautiful' or 'lucky' are words i'd use to describe it. Did you catch that the males of tuskless mothers generally don't survive, decimating the male population? It's a tragic and desperate response, though quite incredible that such a dramatic evolutionary trait can occur. It makes me wonder what we could become, if only...
> if only...
If only humans were harvested for bony growths?
If only humans were harvested for bony growths?
Tusks are not bones
Maybe the males will evolve ways to survive with the tusklessness gene.
Life, uh, finds a way…
Beautiful, lucky, bad
Incredible, good
Incredible, good
Not quite sure what you're getting at. The definitions of those words can't simply be categorized as good or bad. Beautiful and lucky do, however, somewhat infer a positive outcome in the context they were used. Incredible infers neither positive nor negative. It means that it's simply extraordinary that such a thing could occur, outside the bounds of previous beliefs.
I personally find the natural selection process to be beautiful to witness, the adaptive pressures to be incredible, and the cause to be tragic
Not mutually exclusive
Not mutually exclusive
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Context matters.
It never needed elaboration even from the person you initially replied to.
Yet here we are. Thanks for contributing.
Its important to realize what this "response" actually is. Nature isn't actively doing anything. You have 100 elephants, maybe 5 are typically born without tusks. Suddenly you kill the other 95 for their tusks, leaving behind those 5 to survive and reproduce and next generation, 33 of your 100 elephants are without tusks or something like that. Over time, humans are acting as a predator in the environment, driving a selective pressure that reduces the fitness of the tusk trait relative to the no tusk trait
I think the above commenter recognized that; that's exactly how these evolutions pretty much always work in nature, not unique to this case.
Right, but "natural selection" generally doesn't include human influence, but that's semantics. Would you also say that fruits that are selectively bred to be bigger and juicier are also under the influence of "natural selection"?
I wouldn't, because a fruit bred to be bigger and juicier is engineered by humans for their own benefit, while an elephant evolving to not have tusks is evolution going against human benefit.
I believe natural selection includes the influence of any species related to the species in question as predator or prey, and humans in this case are predators. We may historically be responsible for far more processes of natural selection than we're aware of!
You're right that it's exceedingly rare to see us so directly play a role in natural selection today (as opposed to indirectly through affecting the environment), which makes this very interesting.
I believe natural selection includes the influence of any species related to the species in question as predator or prey, and humans in this case are predators. We may historically be responsible for far more processes of natural selection than we're aware of!
You're right that it's exceedingly rare to see us so directly play a role in natural selection today (as opposed to indirectly through affecting the environment), which makes this very interesting.
I’m not sure where the distinction between “natural” or “artificial” selection is, or if it matters. But it seems clear that humans and our technology are capable of creating far more pressure for other species to either evolve or die if we target them for some reason.
If it weren’t for us hunting these elephants for their tusks, there isn’t a reason they’d evolve in this manner. So I just wouldn’t call that evolution by natural selection. Same thing if we set off to exterminate all mosquitoes.
But I do get your point. I’m conflicted if we can count ourselves as any other predator species when discussing evolution.
If it weren’t for us hunting these elephants for their tusks, there isn’t a reason they’d evolve in this manner. So I just wouldn’t call that evolution by natural selection. Same thing if we set off to exterminate all mosquitoes.
But I do get your point. I’m conflicted if we can count ourselves as any other predator species when discussing evolution.
Humans aren't some supernatural force. We're very much a part of nature as well.
I agree, but we also make the very language we're using to describe stuff, and sometimes it's useful to differentiate some things. Very often, it's useful to separate human-caused and non-human caused impacts, such as with climate change.
Of course, because “nature” doesn’t actually exist, it is a concept in the human mind. There is only matter and physical law. What we are simply witnessing is individuals with certain genetic traits surviving in far greater numbers than those who lack them in the current environment, and thus passing those same genes to offspring, propagating them exponentially.
I mean, "nature" never "actively" does anything, there is no active entity that is "nature". It's a metaphor, in all cases.
Put this in context of a lot of other species who were not able to evolve a mechanism like that.
The way I understand this there was likely a very small population of elephants already without tusks, maybe some kind of genetic defect that happened to be an advantage once you add greedy people into the mix. Or what else is possible is that there was one off mutation that produced small family of elephants that poachers wouldn't touch and these spread over decades.
Think about this, if today Covid mutated to kill almost all people but spared 0.1% with a certain gene, you would suddenly observe entire human population becoming immune to Covid.
This does not necessarily mean any new genetic material or "nature responding". Maybe nobody noticed the gene and it suddenly became very visible and comprising large part of population (while it declined dramatically as elephant population did). We may have missed elephants without tusks because they were just freak of nature but now they become proliferating because it becomes an advantage.
EDIT:
Selective pressure is part of evolution process, but it is not enough for evolution.
Evolution requires both mutation AND selection.
So, if the mutation was present BEFORE poachers happened, you can't really say that Mother Nature RESPONDED to poaching by evolving new mechanism. The word "response" implies causal relationship between poachers and mutation+selection of better equipped elephants. But if the mutation has already been present then there is no causal relationship and this wasn't a new mechanism.
The way I understand this there was likely a very small population of elephants already without tusks, maybe some kind of genetic defect that happened to be an advantage once you add greedy people into the mix. Or what else is possible is that there was one off mutation that produced small family of elephants that poachers wouldn't touch and these spread over decades.
Think about this, if today Covid mutated to kill almost all people but spared 0.1% with a certain gene, you would suddenly observe entire human population becoming immune to Covid.
This does not necessarily mean any new genetic material or "nature responding". Maybe nobody noticed the gene and it suddenly became very visible and comprising large part of population (while it declined dramatically as elephant population did). We may have missed elephants without tusks because they were just freak of nature but now they become proliferating because it becomes an advantage.
EDIT:
Selective pressure is part of evolution process, but it is not enough for evolution.
Evolution requires both mutation AND selection.
So, if the mutation was present BEFORE poachers happened, you can't really say that Mother Nature RESPONDED to poaching by evolving new mechanism. The word "response" implies causal relationship between poachers and mutation+selection of better equipped elephants. But if the mutation has already been present then there is no causal relationship and this wasn't a new mechanism.
> This does not necessarily mean any new genetic material or "nature responding".
But this is exactly how evolution works. There are always mutations in every generation, and sometimes those mutations are beneficial. These genes are being selected by the organism's environment, and if the environment changes, then the genes that are selected will be different. That is "nature responding". Elephants without tusks (or very small ones) are more likely to survive and produce offspring.
But this is exactly how evolution works. There are always mutations in every generation, and sometimes those mutations are beneficial. These genes are being selected by the organism's environment, and if the environment changes, then the genes that are selected will be different. That is "nature responding". Elephants without tusks (or very small ones) are more likely to survive and produce offspring.
I would argue what you describe is Evolution as broken into the two pieces: Genetic Drift and Natural Selection.
Genetic Drift is always occurring randomly. Some elephants had a "genetic defect" to live without tusks before poaching. Some humans had the 0.1% resistance to the hypothetical super-covid before the disease.
As new environmental conditions emerge (human poaching, hypothetical super-covid, etc), some genes are far better adapted to the new environment (tuskless, covid resistance, etc). Those genes then thrive in the new environment and consume the available resources left by those killed off.
Genetic Drift is always occurring randomly. Some elephants had a "genetic defect" to live without tusks before poaching. Some humans had the 0.1% resistance to the hypothetical super-covid before the disease.
As new environmental conditions emerge (human poaching, hypothetical super-covid, etc), some genes are far better adapted to the new environment (tuskless, covid resistance, etc). Those genes then thrive in the new environment and consume the available resources left by those killed off.
> What I mean is that it is possible (and I think very likely) this isn't feat of nature suddenly evolving some new defense mechanism as response to poachers.
That's not how evolution works. Evolution doesn't ever involve a "feat of nature suddenly evolving defense mechanisms".
I don't understand this comment, unless it's a way to say the above, that evolution does not involve sudden spontaneous changes in response to an external stimuli.
That's not how evolution works. Evolution doesn't ever involve a "feat of nature suddenly evolving defense mechanisms".
I don't understand this comment, unless it's a way to say the above, that evolution does not involve sudden spontaneous changes in response to an external stimuli.
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It's too bad there is not a gene for making the tusk highly radioactive or shoot out like rockets at the poachers. I guess that's asking a lot of evolution - it's already done a lot for us.
lol, elephants would be wiped out in a few years if they start doing something like that. First rule of dealing with humans is not to be too effective at it.
It's also interesting that a single mutation can cause this lack of tusks. That reinforces another concept for me - the ability to adapt is also important and has been selected for. Meaning simple genes to define structure are preferable to complex sets of them.
On a related note, if "ability to evolve" is a characteristic that can be selected for that would explain why all complex life uses sexual reproduction. Mixing genes offers such advantages that most everything that can't do it is still basically bacteria.
On a related note, if "ability to evolve" is a characteristic that can be selected for that would explain why all complex life uses sexual reproduction. Mixing genes offers such advantages that most everything that can't do it is still basically bacteria.
> It's also interesting that a single mutation can cause this lack of tusks. That reinforces another concept for me - the ability to adapt is also important and has been selected for. Meaning simple genes to define structure are preferable to complex sets of them.
I wouldn't get too attached to that idea... in a lot of cases, having one gene responsible for producing a phenotype can be a very bad thing, like oncogenes (responsible for the growth of cancers) and a bunch that determine development and/or aging.
> On a related note, if "ability to evolve" is a characteristic that can be selected for that would explain why all complex life uses sexual reproduction. Mixing genes offers such advantages that most everything that can't do it is still basically bacteria.
Again, sometimes. There are lizards and bugs that clone themselves (parthanogenesis) which can be really handy for when the population isn't doing so hot.
I wouldn't get too attached to that idea... in a lot of cases, having one gene responsible for producing a phenotype can be a very bad thing, like oncogenes (responsible for the growth of cancers) and a bunch that determine development and/or aging.
> On a related note, if "ability to evolve" is a characteristic that can be selected for that would explain why all complex life uses sexual reproduction. Mixing genes offers such advantages that most everything that can't do it is still basically bacteria.
Again, sometimes. There are lizards and bugs that clone themselves (parthanogenesis) which can be really handy for when the population isn't doing so hot.
I am not sure you read the article, because the number of large-scale side effects this single evolutionary treat evokes is in rather starting contrast with your "the responsiveness of evolution is beautiful in this case."
but the tusks had a purpose to defend and now they are defenseless.
Stomping is a common way for elephants to deal with predators. Tusks are used a lot as a tool though.
If the probability to get killed for the tusks is higher than get killed by predators then it's an advantage.
There are short-term and long-term advantages and disadvantages, though.
From the article, it sounds like this may have protected them from human predation, but there may be significant long-term negative impacts on the species due to the lack of viable male offspring.
Survive more easily for a couple generations, but go extinct as an all-female species after a couple more...
From the article, it sounds like this may have protected them from human predation, but there may be significant long-term negative impacts on the species due to the lack of viable male offspring.
Survive more easily for a couple generations, but go extinct as an all-female species after a couple more...
What do the males die of exactly? Not clear to me.
Seems like the mutation kills male embryos.
https://www.science.org/doi/10.1126/science.abe7389
> Survey data revealed tusk-inheritance patterns consistent with an X chromosome–linked dominant, male-lethal trait. Whole-genome scans implicated two candidate genes with known roles in mammalian tooth development (AMELX and MEP1a), including the formation of enamel, dentin, cementum, and the periodontium. One of these loci (AMELX) is associated with an X-linked dominant, male-lethal syndrome in humans that diminishes the growth of maxillary lateral incisors (homologous to elephant tusks).
https://www.science.org/doi/10.1126/science.abe7389
> Survey data revealed tusk-inheritance patterns consistent with an X chromosome–linked dominant, male-lethal trait. Whole-genome scans implicated two candidate genes with known roles in mammalian tooth development (AMELX and MEP1a), including the formation of enamel, dentin, cementum, and the periodontium. One of these loci (AMELX) is associated with an X-linked dominant, male-lethal syndrome in humans that diminishes the growth of maxillary lateral incisors (homologous to elephant tusks).
Why is it possible for us to have a 50:50 gender ratio?
Why haven't mothers that only give birth to girls taken over the world? Do unpaired girls really die that quickly?
Why haven't mothers that only give birth to girls taken over the world? Do unpaired girls really die that quickly?
Humans have near but exactly 1:1 ( 1.05-1.07 favoring males at birth ). Fisher's principle[1] explains why this 1:1 is common.
There is big imbalance problem for humans as well, many cultures prefer male children over females, the two largest countries - India and China have big imbalance for different reasons there is estimated 100 million less girls than boys in these two countries alone as result of sex selection/ infanticide etc .
[1] https://en.wikipedia.org/wiki/Fisher%27s_principle
There is big imbalance problem for humans as well, many cultures prefer male children over females, the two largest countries - India and China have big imbalance for different reasons there is estimated 100 million less girls than boys in these two countries alone as result of sex selection/ infanticide etc .
[1] https://en.wikipedia.org/wiki/Fisher%27s_principle
That is both fascinating and deeply sad at the same time.
Humanity is a part of nature and we are drivers of an epochal natural selection (and extinction) event. This has already happened and will continue to do so.
This is such a weird to put eugenics. Say I kill all blue eyed people, would you then say "People are evolving brown eyes due to this guy" ?
It's not a consequence intended by ivory poachers.
Alright, eugenics wasn't the right word. But still this isn't evolution in the same way getting a medical intervention isn't. If you want to include everything we do as part of evolution, which is a defensible position, then all murders would be natural, this is not a practical perspective for a society.
What implications does murder being natural carry?
For instance, most responses to murder are natural in exactly the same sense that murder is natural. Things like a legal system and imprisonment are sophisticated group responses to murder, but they aren't somehow separate from our nature because of that, they are part of it.
For instance, most responses to murder are natural in exactly the same sense that murder is natural. Things like a legal system and imprisonment are sophisticated group responses to murder, but they aren't somehow separate from our nature because of that, they are part of it.
Only the fourteenth story about this in the past week on here
1cvmask(4)
Ansil849(7)
So it's a significant change, but it's not like this property was coming out of nowhere. It started off about as common as humans having green eyes.