Misconceptions about Evolution(evolution.berkeley.edu)
evolution.berkeley.edu
Misconceptions about Evolution
http://evolution.berkeley.edu/evolibrary/misconceptions_faq.php
96 comments
More to the point:
Theories don't become laws, theories generate laws; testing those laws is a test of the theory. Laws are mathematical equations which relate observable quantities such that we get quantitative predictions.
The Ideal Gas Law, PV = nRT, is one example: It relates Pressure (P), Volume (V), number of moles of gas (n), a physical constant (R), and Temperature (T) such that we can predict the values of certain traits, or the relationships between traits, given some known or hypothesized values for the other traits. The theory it's part of is the one that says gasses are made out of tiny particles called atoms or molecules, which fly around freely and bounce off each other and solid surfaces with a speed proportional to their temperature. Every time the Ideal Gas Law makes a good prediction, that theory gets validated.
Theories don't become laws, theories generate laws; testing those laws is a test of the theory. Laws are mathematical equations which relate observable quantities such that we get quantitative predictions.
The Ideal Gas Law, PV = nRT, is one example: It relates Pressure (P), Volume (V), number of moles of gas (n), a physical constant (R), and Temperature (T) such that we can predict the values of certain traits, or the relationships between traits, given some known or hypothesized values for the other traits. The theory it's part of is the one that says gasses are made out of tiny particles called atoms or molecules, which fly around freely and bounce off each other and solid surfaces with a speed proportional to their temperature. Every time the Ideal Gas Law makes a good prediction, that theory gets validated.
I'm going to have to disagree. There's no meaningful distinction between "laws" and "theories". One famous consequence of the theory of special relativity is the mass-energy equation - but we do not call E = mc^2 a "law". We just say it's a part of the theory of special relativity.
That, however, does not mean the theory of relativity and E = mc^2 has a lower status than Newton's law of universal gravitation and F = (G m1 m2 )/r. That we call one a "theory" and the other a "law" is just an accident of speech. It's not even a difference of semantics - in this context, "law" and "theory" have the same meaning. We just continue to say "law" for some things for historical reasons.
That, however, does not mean the theory of relativity and E = mc^2 has a lower status than Newton's law of universal gravitation and F = (G m1 m2 )/r. That we call one a "theory" and the other a "law" is just an accident of speech. It's not even a difference of semantics - in this context, "law" and "theory" have the same meaning. We just continue to say "law" for some things for historical reasons.
Perhaps you're right. Mark this one down to schools teaching outdated things as fact, I suppose.
Still, my idea is better than the "hypotheses become theories, which become laws" nonsense, which is still taught at the elementary school level.
Still, my idea is better than the "hypotheses become theories, which become laws" nonsense, which is still taught at the elementary school level.
We call it the law of conservation of mass.
Or well its a limit case, but yeah we absolutely do call it a law.
Theory is the explanation, law is the model.
Or well its a limit case, but yeah we absolutely do call it a law.
Theory is the explanation, law is the model.
The distinction you propose is demonstrably not true in modern theories. (Where "modern" means a bit over 100 years old.) We call such things a law, but there is no difference between a theory and a law. Such "laws" just predate our current philosophy of science, and we continue using names like "the Ideal Gas Law" because we always have. If someone came up with an equivalent thing now, we would not use the term "law" - which we can observe with physics from the 20th century.
This is literally semantics.
The vast majority of people know what an "accepted fact" is, and they also know what a "proposed model of reality" is (even if they don't use such phrases).
The opposition to evolutionary theory as a model of reality is a topic that principally obsesses only a specific population: American Protestants.
In most of the Western world, including in the Catholic Church with its over 1 billion adherents, evolution is an "accepted fact" (or "scientific theory" however that may be rendered semantically).
The vast majority of people know what an "accepted fact" is, and they also know what a "proposed model of reality" is (even if they don't use such phrases).
The opposition to evolutionary theory as a model of reality is a topic that principally obsesses only a specific population: American Protestants.
In most of the Western world, including in the Catholic Church with its over 1 billion adherents, evolution is an "accepted fact" (or "scientific theory" however that may be rendered semantically).
It's not just semantics. Maybe some times it is, but not always, and I even think, not usually. Many people don't actually understand the basics of scientific theories, evidence and falsification. It requires going beyond learning just the "scientific process", and going into the actual philosophy of science. In my experience, that is not commonly known.
Stressing the term "theory" by creationists attacking evolution is a rhetorical device intended to imply that "even scientists don't know".
Obviously, scientists, and other educated people, know that this attack is misguided.
However, recognizing that such arguments are indeed rhetorical, rather than logical, is a step towards not having to go through them again and again...
Obviously, scientists, and other educated people, know that this attack is misguided.
However, recognizing that such arguments are indeed rhetorical, rather than logical, is a step towards not having to go through them again and again...
I'm making a different point. People who make that attack have a fundamental misunderstanding of how science works. They don't understand that it is not possible to prove a theory correct, only falsify it. They don't understand that quantity and quality of supporting evidence matter. They don't understand the difference between "proof" and "evidence". They don't understand that their arguments could be levied against any scientific theory, including ones that they accept. That they can do this means they don't understand how science works.
But, nor do a lot of people who don't make such rhetorical attacks. I think that the philosophy of science is an easy thing to miss - it's possible to make it through a Bachelor's program in science without really being forced to think about it.
But, nor do a lot of people who don't make such rhetorical attacks. I think that the philosophy of science is an easy thing to miss - it's possible to make it through a Bachelor's program in science without really being forced to think about it.
>They don't understand that their arguments could be levied against any scientific theory, including ones that they accept. That they can do this means they don't understand how science works.
Exactly, which is why epistemological arguments won't win the evolution versus creation debate.
Exactly, which is why epistemological arguments won't win the evolution versus creation debate.
I have absolutely heard people say, "Evolution is just a theory"
Some propose using the word theorem to differentiate between these two meanings.
I wrote a novel based in part around the idea that one could prove something like Boltzmann's H-theorem (which has problems of its own) for evolution: http://www.amazon.com/Darwins-Theorem-TJ-Radcliffe-ebook/dp/...
Darwin's Theorem would start with the facts about genetic material--the probability distributions for replication--and use further distributions of features, consequences for reproductive advantage, and so on to demonstrate that it is mathematically necessary for evolution to give access to a more-or-less unbounded adaptive landscape.
The book is actually mostly about sex, violence, politics, religion, regret and redemption, so it's not as dry as that probably makes it sound!
Darwin's Theorem would start with the facts about genetic material--the probability distributions for replication--and use further distributions of features, consequences for reproductive advantage, and so on to demonstrate that it is mathematically necessary for evolution to give access to a more-or-less unbounded adaptive landscape.
The book is actually mostly about sex, violence, politics, religion, regret and redemption, so it's not as dry as that probably makes it sound!
The fact that people don't understand the word "theory" is worrying because it's a flag that they don't understand scientific method. People don't know that a "hypothesis" is the guessing[1] part and that a hypothesis supported by experimental evidence becomes a theory - it becomes less of a guess.
Popular science programmes or reporting fail to explain this and reporting often uses the word theory to mean "has a hunch".
[1] supported by principles I guess.
Popular science programmes or reporting fail to explain this and reporting often uses the word theory to mean "has a hunch".
[1] supported by principles I guess.
I don't think your explanation is quite right, either. Typically, a "hypothesis" is in the form of "we think x will happen in y circumstance". Then they run some experiments to see if that's the case. If it is, then they may try to come up with a theory to explain why, then run (many) additional experiments to test the theory.
In other words, I usually use the word "hypothesis" to mean a simple prediction of outcome, without any explanation of how. A "theory" needs some explanation in it, not just a prediction of correlation.
In other words, I usually use the word "hypothesis" to mean a simple prediction of outcome, without any explanation of how. A "theory" needs some explanation in it, not just a prediction of correlation.
Sometimes "hypothesis" persists well past the guessing phase (e.g. "The Hygiene Hypothesis" is pretty well supported, even if it's not a complete explanation of autoimmunity and allergies)
I keep telling these people that we have things like number theory as well that's as hard science as it can get :) - and it's still a theory. I'm not sure how 'strong' is the word 'theory' in English though, but in my mother tongue it definitely has the feeling of being a 'guess'.
In informal English communication "theory" is a synonym for "hypothesis". It's also far more commonly used in everyday communication than hypothesis, which looks/sounds more formal or technical.
This is mostly the problem, I think. In this sense, both 'theory' and 'hypothesis' are antonyms of 'fact'. Leads directly to uninformed people saying that evolution hasn't been established as a fact, or that it's not "true".
Yeah, in English I'd say the word 'theory' has three distinct meanings. A guess, as in 'I have a theory about this;' a scientific theory, i.e. set of testable hypotheses, etc.; and a set of related propositions that form a cohesive subject (like number theory).
Mathematics is not a science, and number 'theory' is not theory as meant in the sciences.
Unlike in science, where enough evidence for a particular hypothesis makes it generally believed to be true, in math empirical evidence is not and will never be enough to classify a statement as true.
Unlike in science, where enough evidence for a particular hypothesis makes it generally believed to be true, in math empirical evidence is not and will never be enough to classify a statement as true.
Thanks. Is there a resource or a book on amazon that focuses on the testability of inter-species evolution ? I've been a bit frustrated by this as most people just allude to the fact that it took thousands or millions of years so hard to test it - but we should extra-polate some observed lab principles at a much tinier and then scale the intuition by a billion times to get inter species evolution.
Specifically are there any:
1. Simulations (i.e. code up the actors in the system and let it proceed it a accelerated time scale similar to what we do for space simulations for heavenly bodies)
2. Emulations (not computational but demonstrating using a real life model of some kind)
3. Lab demonstrations of this happening
4. Reproductions of the whole set of mechanisms that allow a species to evolve into something new that we would classify as a different species
that clearly show the evolution principles in effect for a reasonably complex inter-species case.
I have been frustrated from Richard Dawkins's accounts too. I once read his essay on how the eye might have evolved. His accounts tend to be so speculative and full of "should"s and "must"s, its very off putting.
Edit: This book in fact is the best writing on evolution of eyes: http://www.amazon.com/Evolutions-Witness-How-Eyes-Evolved/dp...
But it completely skips the actual mechanism or testability of anything it says. So basically doesn't address the how at all. A resource that actually addresses the HOW and not just conjecture on the WHAT would be really cool.
Specifically are there any:
1. Simulations (i.e. code up the actors in the system and let it proceed it a accelerated time scale similar to what we do for space simulations for heavenly bodies)
2. Emulations (not computational but demonstrating using a real life model of some kind)
3. Lab demonstrations of this happening
4. Reproductions of the whole set of mechanisms that allow a species to evolve into something new that we would classify as a different species
that clearly show the evolution principles in effect for a reasonably complex inter-species case.
I have been frustrated from Richard Dawkins's accounts too. I once read his essay on how the eye might have evolved. His accounts tend to be so speculative and full of "should"s and "must"s, its very off putting.
Edit: This book in fact is the best writing on evolution of eyes: http://www.amazon.com/Evolutions-Witness-How-Eyes-Evolved/dp...
But it completely skips the actual mechanism or testability of anything it says. So basically doesn't address the how at all. A resource that actually addresses the HOW and not just conjecture on the WHAT would be really cool.
I get what you're asking. You want a testable account of how any given species went from what we would call species X to what we would call species Y. There is probably never going to be such a level of resolution in our analysis that would satisfy even the staunchest naysayer. To really comprehend evolution requires an imagination capable of extrapolating a given set of principles into a framework that entails the very minuscule available data we do have under one encompassing theory. That theory is evolution. It is not something that can be fully understood in isolation.
This doesn't directly answer your question, but this was a key insight that finally made the entire picture click in my mind. Your question of wanting hard evidence of cross-species evolution is a red-herring and a distraction to your understanding. The concept of species is not a biological reality. Any definition we can come up with for a species, we can find many instances that break the definition. What we see as a species is just groups of individuals who have exchanged genes in recent history. There is no demarcation to delineate a transition between one species and another: (in the case of sexual reproduction) at every point a child can mate with its parents, with no exceptions (except for degenerate cases). This is true for every species that sexually reproduces, going all the way back to the origin of sexual reproduction. The reason groups of animals that represent a unified gene pool look so different is that groups of individuals fall into stable states with their environmental niche, while other groups fall into other stable states for other niches. Animals appear to be delineated by clear species simply as a function of our perspective from a single time slice. If we could observe gradual change over millions of years, we would see many splitting branches and merging branches, branches that get further apart and then seed an explosion of many smaller branches (i.e. when say land animals split from birds), etc etc. But in reality, every individual is a single branch on this tree. What we judge as a species are just branches that are 'close together' in this tree such that they look like a single unit.
This doesn't directly answer your question, but this was a key insight that finally made the entire picture click in my mind. Your question of wanting hard evidence of cross-species evolution is a red-herring and a distraction to your understanding. The concept of species is not a biological reality. Any definition we can come up with for a species, we can find many instances that break the definition. What we see as a species is just groups of individuals who have exchanged genes in recent history. There is no demarcation to delineate a transition between one species and another: (in the case of sexual reproduction) at every point a child can mate with its parents, with no exceptions (except for degenerate cases). This is true for every species that sexually reproduces, going all the way back to the origin of sexual reproduction. The reason groups of animals that represent a unified gene pool look so different is that groups of individuals fall into stable states with their environmental niche, while other groups fall into other stable states for other niches. Animals appear to be delineated by clear species simply as a function of our perspective from a single time slice. If we could observe gradual change over millions of years, we would see many splitting branches and merging branches, branches that get further apart and then seed an explosion of many smaller branches (i.e. when say land animals split from birds), etc etc. But in reality, every individual is a single branch on this tree. What we judge as a species are just branches that are 'close together' in this tree such that they look like a single unit.
Thanks - your answer is reasonable. What I was really looking for is a mechanism that demonstrates this:
"Animals appear to be delineated by clear species simply as a function of our perspective from a single time slice. If we could observe gradual change over millions of years, we would see many splitting branches and merging branches, branches that get further apart and then seed an explosion of many smaller branches (i.e. when say land animals split from birds), etc etc."
The idea of gradual change is fine to me - and the term species seems to create too much confusion. But the fact that gradual change over time can create seemingly distinct states (lets not call them species) still boggles me mind when I try to conceive of the mechanism. Is asking that question a red-herring or completely unreasonable ? In fact that is the part I find most fascinating. The fact that the change was gradual doesn't preclude from the fact that this gradual change did lead to states which were observed to be quite distinct. One doesn't preclude the other.
To explain more of where I am coming from: As a person who writes reasonably complex software for a living, I am amazed by the "software" in the brain if you will i.e. its remarkable cognitive capacity for many tasks that we are still in the process of replicating in AI. I find it hard to understand how this could arise as a step by step gradual change purely aided by a favorable set of environmental properties. So something to that effect would be really cool to understand (And even emulate or copy in our software development practices). I am a bit disappointed that there are no simulations that can be done or we don't understand the mechanisms well enough to do this.
For a very specific example, it would be cool to simulate "This is how the eye came into being.". Not just enumerating the commonalities between eyes of different species - I find the "commonality" argument as being "factual evidence" of origin of the eye very weak personally. I know its been accepted as fact by most or everyone else but something that would demonstrate the underlying "gradual" principles at work to evolve an eye for example would be uber-cool and satisfying in my book. I don't understand why this question is stupid or or unscientific.
"Animals appear to be delineated by clear species simply as a function of our perspective from a single time slice. If we could observe gradual change over millions of years, we would see many splitting branches and merging branches, branches that get further apart and then seed an explosion of many smaller branches (i.e. when say land animals split from birds), etc etc."
The idea of gradual change is fine to me - and the term species seems to create too much confusion. But the fact that gradual change over time can create seemingly distinct states (lets not call them species) still boggles me mind when I try to conceive of the mechanism. Is asking that question a red-herring or completely unreasonable ? In fact that is the part I find most fascinating. The fact that the change was gradual doesn't preclude from the fact that this gradual change did lead to states which were observed to be quite distinct. One doesn't preclude the other.
To explain more of where I am coming from: As a person who writes reasonably complex software for a living, I am amazed by the "software" in the brain if you will i.e. its remarkable cognitive capacity for many tasks that we are still in the process of replicating in AI. I find it hard to understand how this could arise as a step by step gradual change purely aided by a favorable set of environmental properties. So something to that effect would be really cool to understand (And even emulate or copy in our software development practices). I am a bit disappointed that there are no simulations that can be done or we don't understand the mechanisms well enough to do this.
For a very specific example, it would be cool to simulate "This is how the eye came into being.". Not just enumerating the commonalities between eyes of different species - I find the "commonality" argument as being "factual evidence" of origin of the eye very weak personally. I know its been accepted as fact by most or everyone else but something that would demonstrate the underlying "gradual" principles at work to evolve an eye for example would be uber-cool and satisfying in my book. I don't understand why this question is stupid or or unscientific.
The way you ask that eye question is not stupid nor unscientific.
Sadly eyes are used by creationists to ask a similar question in an attempt to discredit evolution. "The eye is so complex and it doesn't work unless it's all there so how could it gradually develop?"
Sadly eyes are used by creationists to ask a similar question in an attempt to discredit evolution. "The eye is so complex and it doesn't work unless it's all there so how could it gradually develop?"
If you just want to play with something that uses a genetic algo, there is this: http://boxcar2d.com/
You can handcraft a simple starting point and let it gradually evolve in different environments. Note how the different environments bring out different traits even tho the starting point is the same. I don't know how many hrs I lost playing with this. :)
You can handcraft a simple starting point and let it gradually evolve in different environments. Note how the different environments bring out different traits even tho the starting point is the same. I don't know how many hrs I lost playing with this. :)
A good way to think about it is to imagine a prism's dispersion of white light. There is clearly red and clearly orange but it gets tricky finding the place where "red becomes orange". The closer you look, the harder it is to choose a spot.
I think the fundamental problem is that "species" is a way for human to divide up organisms, rather than a fundamental function of biology or evolution. Every organism has its own DNA but "species" is a way of trying to group those into patterns that make sense to humans.
That is, it's easy enough to demonstrate that evolution drives changes in DNA. That's objective. Whether or not you call it a species change is subjective.
That is, it's easy enough to demonstrate that evolution drives changes in DNA. That's objective. Whether or not you call it a species change is subjective.
Not entirely. We can define species as groups of organisms that can't reproduce with each other. (For species that have sexual reproduction, of course.) See: http://bioteaching.com/modes-of-speciation/
Let me phrase the question a different way - since species seems to be overloaded. What stable state of organism led to the evolution of Giraffe ? Lets call that organism X. (I actually don't know what X is, is it a horse or a zebra or a donkey?)
Is there a simulation that would demonstrate X evolving to a Giraffe or test it ?
Or put another way, if we were to take some snapshots at times where we could consider the organism to be different enough according to the modern "species" classification say A -> B -> C -> D -> E, is there a way to test D -> E or B-> C using the stated principles/theory ?
Is there a simulation that would demonstrate X evolving to a Giraffe or test it ?
Or put another way, if we were to take some snapshots at times where we could consider the organism to be different enough according to the modern "species" classification say A -> B -> C -> D -> E, is there a way to test D -> E or B-> C using the stated principles/theory ?
There is no such thing as a "stable state of organism" in this context. Remove all your goalposts because they are confusing you. Evolution is a continuum.
Then what is evolution trying to explain ? I thought it was explaining how primates evolved to humans, not just micro evolution at the DNA level ? For all practical purposes these are considered stable states in that they are different enough (visually, internally, intellectually) so as not to be considered continuous i.e. just differing by some epsilon.
Are you saying evolution does not claim to answer this and this is a question not worth asking?
I have a feeling the gist of what I am asking is clear enough but we are getting lost in words. I just asked for a link on Amazon that talks about testing/simulating/demonstrating evolution for snapshots enough far apart in time where we would say yes these organisms are pretty different, something like the snapshots demonstrated here: http://www.bot1320.nicerweb.com/Locked/media/ch11/taxonomy.h...
Are you saying evolution does not claim to answer this and this is a question not worth asking?
I have a feeling the gist of what I am asking is clear enough but we are getting lost in words. I just asked for a link on Amazon that talks about testing/simulating/demonstrating evolution for snapshots enough far apart in time where we would say yes these organisms are pretty different, something like the snapshots demonstrated here: http://www.bot1320.nicerweb.com/Locked/media/ch11/taxonomy.h...
One of several problems is that for many of the organisms with a short enough generation time to run an experiment like this (see Lenski's experiments with E. coli: http://en.wikipedia.org/wiki/E._coli_long-term_evolution_exp... ) the notion of a "steady state species" in terms of your thinking (Baboon vs. Human vs. Gorilla) is entirely false.
Are you just asking about macroevolution? https://en.wikipedia.org/wiki/Macroevolution
"micro evolution" You are being confused by terms that were invented by a group of people (Discovery Institute) that deny evolution because of their religion not because of lack of evidence. The snapshot evidence you need is found in the genome (genomes that developed over billions of years of "micro evolution") of every organism on the planet not just primates. You can't just ignore that and ask why we can't observe lizards turning into birds overnight.
Edit: I wasn't aware of this until now. We actually have observed one species ("species" being defined as scott_s mentioned up-thread) evolve into another.
http://blogs.scientificamerican.com/science-sushi/2011/12/18...
Edit: I wasn't aware of this until now. We actually have observed one species ("species" being defined as scott_s mentioned up-thread) evolve into another.
http://blogs.scientificamerican.com/science-sushi/2011/12/18...
Why do you think we should be able to extrapolate millions of years of random mutation into the future and be able to test it? If you want evidence there are plenty of other places to look.
This is one of those things where a whole lot of redundant societal arguments and misunderstandings could be averted if we just used two different words for the two different concepts.
exactly my thoughts too. If only we can use 2 different words... sigh
The real problem is however a philosophical one, how to drive down the point that there is no absolute truth,just absolute contradiction that disproves a (now disfunct) scientific theory . Unless you are making certain axiomatic assumptions or using the constructs of language for example 'all single men are bachelors', the best we can do is let our best theories make predictions and then conduct experiments to test those predictions.
The real problem is however a philosophical one, how to drive down the point that there is no absolute truth,just absolute contradiction that disproves a (now disfunct) scientific theory . Unless you are making certain axiomatic assumptions or using the constructs of language for example 'all single men are bachelors', the best we can do is let our best theories make predictions and then conduct experiments to test those predictions.
Well said.
Yeah, I agree.
I also think getting people everywhere to change the meanings of words is an uphill, possibly impossible battle. We can't even teach people about figurative vs literally.
I think Scientists should give up and get rid of the word "theory". Scientists had no problem renaming the brontosaurus so it shouldn't be as hard as it sounds.
I also think getting people everywhere to change the meanings of words is an uphill, possibly impossible battle. We can't even teach people about figurative vs literally.
I think Scientists should give up and get rid of the word "theory". Scientists had no problem renaming the brontosaurus so it shouldn't be as hard as it sounds.
From my experience, it seems that the biggest misconception about Evolution is that species evolve through some sort of conscious decision-making process, and not really by natural selection and random mutation.
For example, I often hear that a big step in the primate-to-human evolution was when one of our common ancestors "left the trees and started walking bipedally", implying to me at least, that it was some sort of "hey, maybe we should try this today" decision made by an individual to attempt it.
It wasn't. What really happened was that a mutation in the population allowed one individual the ability to walk a bit more upright, and this conferred a special ability for this individual to gather more food or have more offspring, thus propagating the mutated gene(s).
I watch the pop-sci channels regularly, and even they fall victim to this anthropomorphic trap about species "evolving-by-choice".
[edit] I just read this in the OP just below where I stopped...
MISCONCEPTION: Natural selection involves organisms trying to adapt.
For example, I often hear that a big step in the primate-to-human evolution was when one of our common ancestors "left the trees and started walking bipedally", implying to me at least, that it was some sort of "hey, maybe we should try this today" decision made by an individual to attempt it.
It wasn't. What really happened was that a mutation in the population allowed one individual the ability to walk a bit more upright, and this conferred a special ability for this individual to gather more food or have more offspring, thus propagating the mutated gene(s).
I watch the pop-sci channels regularly, and even they fall victim to this anthropomorphic trap about species "evolving-by-choice".
[edit] I just read this in the OP just below where I stopped...
MISCONCEPTION: Natural selection involves organisms trying to adapt.
It's more subtle than that. For example, if walking enabled you to gather more food, then anything that helps you walk better confers an advantage. If food was in trees, walking would be useless.
The best hypothesis for what triggered this change was a shift in climate where trees became less productive and thinned out more, meaning you often had to move quickly from one tree to another on the ground. Anything that enabled you to hustle faster like that gave you a big advantage.
With natural selection you do not have any choices. You survive or you die.
The best hypothesis for what triggered this change was a shift in climate where trees became less productive and thinned out more, meaning you often had to move quickly from one tree to another on the ground. Anything that enabled you to hustle faster like that gave you a big advantage.
With natural selection you do not have any choices. You survive or you die.
> for what triggered this change
You are doing it too. A change is not triggered by anything - you are talking as if there is some latent change waiting to be activated.
You are doing it too. A change is not triggered by anything - you are talking as if there is some latent change waiting to be activated.
A change in selective pressure would trigger a change in the output of selection. The parent's point that reduction in trees would trigger a change to more walking behavior makes sense to me - the environment changed, which caused a change in selective pressures, thus making walking more favorable for survival and "triggering" the change.
A lot of that is tied up on how our language works. "The reason for this is" is ambiguous, because we use 'reason' to describe both purposeful decisions and coincidental explanations.
Have you ever tried to distinguish between "explaining" your behavior and "making excuses"? There is no clear difference -- or rather, people don't know what the difference is if there is one. It's not encoded in the language, but in our intent.
There is a lot of confusion about evolution because we simply don't have the words to make things less confusing. Trained scientists are better at it because they are better trained to see structure independent of language -- (I.e., to think logically instead of culturally.)
Have you ever tried to distinguish between "explaining" your behavior and "making excuses"? There is no clear difference -- or rather, people don't know what the difference is if there is one. It's not encoded in the language, but in our intent.
There is a lot of confusion about evolution because we simply don't have the words to make things less confusing. Trained scientists are better at it because they are better trained to see structure independent of language -- (I.e., to think logically instead of culturally.)
I think he is using the word more like a way of saying "the group of factors that ultimately led to this change" and not as if there was actually a change waiting for a trigger so that then "it can happen".
At least that's how I read it.
At least that's how I read it.
It was. The change was a shift in the tree population due to a latent factor; this latent factor is what resulted in walker-better-groups to outcompete tree-clinging-groups.
There is no anthropomorphizing here; it's simply semantics.
There is no anthropomorphizing here; it's simply semantics.
[deleted]
> I watch the pop-sci channels regularly, and even they fall victim to this anthropomorphic trap about species "evolving-by-choice".
I think this is, in part, due to their attempts to explain things to viewers by analogy, which often must anthropomorphise things.
I think this is, in part, due to their attempts to explain things to viewers by analogy, which often must anthropomorphise things.
One of the difficulties in this is that experts also anthropomorphise this, even though they know that it is not technically correct. Similar to how a programmer might say that the compiler would get angry.
A misconception that affects the way people think of both evolution and climate change, is the idea that the study of the past is a necessary and integral part of the theory. That's not necessarily true.
Darwin generated his theory of natural selection by observing living species throughout the world, and Mendel developed this theory of genetic inheritance by working with living plants. Biologists studying evolutionary processes today continue to work with living creatures like viruses, bacteria, and insects.
Likewise, the theory of global warming was developed by observing current-day phenomena, like the Earth's surface temperature, absorbtion and re-emission of light by certain gases, the rate of CO2 absorbtion by the ocean, the quantity of manmade and natural emissions, solar energy inputs, orbital variations, etc.
In both cases, it was this study of the present that created additional questions that could be answered by looking at the past. Evolution gave scientists a new way of organizing and studying the fossil record--that was a result of the theory of evolution, not the cause. Likewise, the study of current climate change raised a whole host of questions that scientists could try to answer about the past.
Quite a lot of science works this way. Astrophysics is well known for the Big Bang theory, but the roots of the science are in observing the stars we see today, including our own sun.
Darwin generated his theory of natural selection by observing living species throughout the world, and Mendel developed this theory of genetic inheritance by working with living plants. Biologists studying evolutionary processes today continue to work with living creatures like viruses, bacteria, and insects.
Likewise, the theory of global warming was developed by observing current-day phenomena, like the Earth's surface temperature, absorbtion and re-emission of light by certain gases, the rate of CO2 absorbtion by the ocean, the quantity of manmade and natural emissions, solar energy inputs, orbital variations, etc.
In both cases, it was this study of the present that created additional questions that could be answered by looking at the past. Evolution gave scientists a new way of organizing and studying the fossil record--that was a result of the theory of evolution, not the cause. Likewise, the study of current climate change raised a whole host of questions that scientists could try to answer about the past.
Quite a lot of science works this way. Astrophysics is well known for the Big Bang theory, but the roots of the science are in observing the stars we see today, including our own sun.
> A misconception that affects the way people think is the idea that the study of the past is a necessary and integral part of the theory.
> the roots of the science are in observing the stars we see today
I agree with your point, but just made me smile in that we tend to look at a lot of (possibly) long dead stars from our past, too!
> the roots of the science are in observing the stars we see today
I agree with your point, but just made me smile in that we tend to look at a lot of (possibly) long dead stars from our past, too!
>I agree with your point, but just made me smile in that we tend to look at a lot of (possibly) long dead stars from our past, too!
haha, well said. Although to take it to an extreme, every observation or study would have to have been by studying the past right from the milliseconds in the past to light years in the past.
haha, well said. Although to take it to an extreme, every observation or study would have to have been by studying the past right from the milliseconds in the past to light years in the past.
Our present, but their past--right? :-)
I just recently published a book called "Nature, in Code" [https://leanpub.com/natureincode] that is largely about Evolution - explained by implementing key concepts in JavaScript. It is also a beginner's book for people to learn programming.
From a personal perspective, I've always understood a concept much better once I implemented it in code. Because of that, I started teaching population genetics primarily as a computer lab class. This book is an attempt to be more broad (in terms of subject, and reach).
From a personal perspective, I've always understood a concept much better once I implemented it in code. Because of that, I started teaching population genetics primarily as a computer lab class. This book is an attempt to be more broad (in terms of subject, and reach).
First thing I did was search this article for "gene expression." Had nothing.
I think it is safe to say that this article is behind our current understanding about "evolution" and is in fact spreading some new myths as a direct result.
In the last five or so years it has become more and more clear, that while a mother cannot alter her unborn child's DNA, the mother's environment can cause different gene's within the child's DNA to be activated or deactivated.
So our traditional understanding about "random mutations" and "survival of the fittest" being the primary means by which organisms change or evolve looks to be a gross oversimplification. Since discovering gene expression, the environment may very well shape how the offspring's DNA is used.
There are tens of studies on this, but the vast majority since 2010 (so literally last five years). But the results they're providing give us an entire new avenue to look down and the impact on our understanding of evolution likely needs to shift as a result.
Keep in mind nobody is suggesting people (or animals) have direct control over gene expression, in fact our understanding of how it works is still undeveloped.
This paper covers the topic briefly [PDF]: "Evolution of Gene Expression" http://www.umich.edu/~pwlab/Wittkopp%20et%20al%20reprints/Pr...
I think it is safe to say that this article is behind our current understanding about "evolution" and is in fact spreading some new myths as a direct result.
In the last five or so years it has become more and more clear, that while a mother cannot alter her unborn child's DNA, the mother's environment can cause different gene's within the child's DNA to be activated or deactivated.
So our traditional understanding about "random mutations" and "survival of the fittest" being the primary means by which organisms change or evolve looks to be a gross oversimplification. Since discovering gene expression, the environment may very well shape how the offspring's DNA is used.
There are tens of studies on this, but the vast majority since 2010 (so literally last five years). But the results they're providing give us an entire new avenue to look down and the impact on our understanding of evolution likely needs to shift as a result.
Keep in mind nobody is suggesting people (or animals) have direct control over gene expression, in fact our understanding of how it works is still undeveloped.
This paper covers the topic briefly [PDF]: "Evolution of Gene Expression" http://www.umich.edu/~pwlab/Wittkopp%20et%20al%20reprints/Pr...
The field is called "epigenetics," correct?
Yes but "transgenerational epigenetics" as it is sometimes known has a lot of baggage (and bad ideas). In fact if you look at it historically it has a very bad track record.
Gene expression is something relatively recent that may shake things up (and the research is looking positive). However it doesn't mean that everything within the field of transgenerational epigenetics is accurate or proven.
Gene expression is something relatively recent that may shake things up (and the research is looking positive). However it doesn't mean that everything within the field of transgenerational epigenetics is accurate or proven.
I have previously read the site kindly submitted for discussion today and have recommended it (here on Hacker News, too, as I recall) before. This site is well worth a read. A comment asks for a recommendation of a book about macroevolution, transformation to new species among descendant organisms, and I can not only recommend two books, but also a free website. The website is 29+ Evidences for Macroevolution,[1] which I have recommended often to readers here on Hacker News. The books are Why Evolution Is True by Jerry Coyne[2] and The Greatest Show on Earth by Richard Dawkins.[3] Both books are very readable and interesting and well deserve your attention. There are other good recent books about evolution that help fill in the research findings that have occurred since you or I finished our formal schooling.[4]
[1] http://www.talkorigins.org/faqs/comdesc/
[2] http://www.amazon.com/Why-Evolution-True-Jerry-Coyne/dp/0143...
[3] http://www.amazon.com/The-Greatest-Show-Earth-Evolution/dp/1...
[4] http://www.amazon.com/The-Ancestors-Tale-Pilgrimage-Evolutio...
http://www.amazon.com/Your-Inner-Fish-Journey-3-5-Billion-Ye...
http://www.amazon.com/Endless-Forms-Most-Beautiful-Science/d...
http://www.amazon.com/Making-Fittest-Ultimate-Forensic-Evolu...
[1] http://www.talkorigins.org/faqs/comdesc/
[2] http://www.amazon.com/Why-Evolution-True-Jerry-Coyne/dp/0143...
[3] http://www.amazon.com/The-Greatest-Show-Earth-Evolution/dp/1...
[4] http://www.amazon.com/The-Ancestors-Tale-Pilgrimage-Evolutio...
http://www.amazon.com/Your-Inner-Fish-Journey-3-5-Billion-Ye...
http://www.amazon.com/Endless-Forms-Most-Beautiful-Science/d...
http://www.amazon.com/Making-Fittest-Ultimate-Forensic-Evolu...
My favorite is "survival of the fittest" -- a catch phrase so prone to misinterpretation and so oversimplified that it's basically wrong.
IMO, "survival is fitness" is a much better phrase.
The original form "survival of the fittest" is basically a tautology, but it's rarely taken a such. Even better people don't think of survival as a guarantee, at the individual level it’s fairly random, but people can easily see that some things help or hurt those odds.
The original form "survival of the fittest" is basically a tautology, but it's rarely taken a such. Even better people don't think of survival as a guarantee, at the individual level it’s fairly random, but people can easily see that some things help or hurt those odds.
"Survival of the fittest" is only a tautology if you interpret it to be one, which is pointless, so people tend not to.
People tend not to interpret things in pointless ways because it's pointless. #taut
The big problem lies in misunderstanding what fitness is. Fitness _only_ means surviving long enough to reproduce (and doing it). A genetically fit organism is one that reproduces. To be more fit the organism must reproduce more than others in its species. Conflating fitness with so-called desirable traits is what I most often see.
I've always felt that 'survival of the fit enough' is closer to the intended meaning.
"Survival of some set of the fit" is my favorite.
I like "reproduction of the adequate."
That's great. Really accurate. Also explains why we're all here. :P
What's wrong with it? Or how do people misinterpret it?
Two main ideas I think people may get wrong.
One is that there needs to be survival of an individual (not dying), while it rather refers to survival of a species (not going extinct). This survival thus has little to do with actual life or death, rather it has to do with reproduction. For example a one-day-fly is, generally spoken, in a terrible situation when it comes to survival, it's life/death perspective is awful, just one day. But it survives as a species because its able to reproduce so rapidly that even a short life doesn't make the species go extinct. Evolution doesn't care for survival of an individual as long as that individual manages to reproduce before it does.
The second is that there is somehow some 'fitness' variable, the better the more you survive. So a lion would be more fit than say a fly because it's stronger. But this too refers to a different concept, which is that 'fit' is in relation to the environment. A fly is quite fit to live in many environments over long periods of time, whereas a lion isn't fit for many environments and will have trouble surviving say changes in climate and habitat. Fitness is thus purely in relation to its environment.
So really 'survival of the fittest' is more like 'species fit for the environment will survive long enough to reproduce', or something to that effect. From this then originates the argument that random mutations of a species will create different offspring that is more or less fit for the environment, and those more fit will survive, those less fit will not. That is survival of the fittest. And again, when I refer to survive, I mean the species, on the basis that when individuals of a species are fit for their environment, they have a good chance of reproducing enough offspring before death preventing the species from going extinct.
One is that there needs to be survival of an individual (not dying), while it rather refers to survival of a species (not going extinct). This survival thus has little to do with actual life or death, rather it has to do with reproduction. For example a one-day-fly is, generally spoken, in a terrible situation when it comes to survival, it's life/death perspective is awful, just one day. But it survives as a species because its able to reproduce so rapidly that even a short life doesn't make the species go extinct. Evolution doesn't care for survival of an individual as long as that individual manages to reproduce before it does.
The second is that there is somehow some 'fitness' variable, the better the more you survive. So a lion would be more fit than say a fly because it's stronger. But this too refers to a different concept, which is that 'fit' is in relation to the environment. A fly is quite fit to live in many environments over long periods of time, whereas a lion isn't fit for many environments and will have trouble surviving say changes in climate and habitat. Fitness is thus purely in relation to its environment.
So really 'survival of the fittest' is more like 'species fit for the environment will survive long enough to reproduce', or something to that effect. From this then originates the argument that random mutations of a species will create different offspring that is more or less fit for the environment, and those more fit will survive, those less fit will not. That is survival of the fittest. And again, when I refer to survive, I mean the species, on the basis that when individuals of a species are fit for their environment, they have a good chance of reproducing enough offspring before death preventing the species from going extinct.
>Evolution doesn't care for survival of an individual as long as that individual manages to reproduce before it does.
Evolution doesn't care ever, regardless of whether you reproduce or not. You can evolve to the point of extinction just fine.
Evolution doesn't care ever, regardless of whether you reproduce or not. You can evolve to the point of extinction just fine.
Well, the question is "fit for what?" A male ostrich is obviously not very fit to flee predators, so people who think only in terms of survival have a hard time understanding how it could evolve.
In that case, the answer is "fit to attract a mate." In general, I think the role and implications of sexual selection are underappreciated by folks not familiar with the details of evolutionary theory.
It's not just who survives; it's who reproduces.
In that case, the answer is "fit to attract a mate." In general, I think the role and implications of sexual selection are underappreciated by folks not familiar with the details of evolutionary theory.
It's not just who survives; it's who reproduces.
[deleted]
For one thing, a species doesn't need to be the fittest to survive in its particular environmental niche, merely fit enough...
Unfortunately, I'm afraid that the berkeley.edu domain alone will be enough to raise the hackles of the people that really need to read this.
My employer has a blog series that covers many of these issues with skeptical Christians as the intended audience: http://biologos.org/blog/series/evolution-basics
My employer has a blog series that covers many of these issues with skeptical Christians as the intended audience: http://biologos.org/blog/series/evolution-basics
Lots of people need to read it, including many who consider themselves scientifically literate. Evolution is a very widely misunderstood field, to the extent that many people with biology degrees harbor a number of misconceptions about it.
Then how can we expect anyone else to understand it? If this is the case, why should anyone even try? I'm not saying you're wrong, it just begs the question: "If the people who have undergone training to be prepared in this field can not understand it correctly, why should I (who am not remotely related to the field) understand it correctly or even try to?"
People with CS degrees can still harbour misconceptions about programming or computers. That doesn't mean there is no way to understand computer science, nor no reason to try.
In fact, in an ideal world, evolution wouldn't be an important thing for most people to understand. It is disproportionately important because it is the point of attack of fundamentalists against scientific modernity, and a naive view of evolution can leave people susceptible to their propaganda, and therefore more likely to politically oppose science.
In fact, in an ideal world, evolution wouldn't be an important thing for most people to understand. It is disproportionately important because it is the point of attack of fundamentalists against scientific modernity, and a naive view of evolution can leave people susceptible to their propaganda, and therefore more likely to politically oppose science.
"can not understand" is different than harbouring misconceptions. Many doctors harbour misconceptions about various medical issues, medicine is a big field. That doesn't mean they are incapable of understanding the concept once they look into it.
If the standard for accepting a theory is absolute understanding, then the human race won't get very far. I subscribe to various theories about physics (ie gravity). I don't claim to understand them. But I do not dismiss them simply because I lack a complete understanding. I trust those scientists who do.
If the standard for accepting a theory is absolute understanding, then the human race won't get very far. I subscribe to various theories about physics (ie gravity). I don't claim to understand them. But I do not dismiss them simply because I lack a complete understanding. I trust those scientists who do.
sago hits the nail on the head to answer the "why". When the People have any sort of influence at all, everything becomes politicized, and those who don't want the system to crumble insist that all voters be educated in an ever-increasing set of things in order to vote sanely about them. To question the need to learn a particular thing that's already been politicized like evolution is to question democracy itself.
I highly recommend Richard Dawkins' 1991 Royal Institution Christmas lectures. Dawkins is also an evolutionary biologist.
http://www.richannel.org/christmas-lectures/1991/richard-daw...
http://www.richannel.org/christmas-lectures/1991/richard-daw...
The biggest confusion I have seen from evolution comes from the causality. "$x evolved $y so it could $z"
The reality is much messier and involved a lot of $x dying before one of them was born with something sort of like $y.
The reality is much messier and involved a lot of $x dying before one of them was born with something sort of like $y.
The article itself contains a misconception.
Genetic variation doesn't always come from random mutation. Firstly, there may already be genes in the population that just have never been combined yet. Secondly, DNA can integrated from the environment under the right conditions. The amount of human DNA that is estimated to originate from viruses is astounding. And bacteria have been known to develop antibiotic resistance by taking it from unrelated bacteria that already have resistance.
Genetic variation doesn't always come from random mutation. Firstly, there may already be genes in the population that just have never been combined yet. Secondly, DNA can integrated from the environment under the right conditions. The amount of human DNA that is estimated to originate from viruses is astounding. And bacteria have been known to develop antibiotic resistance by taking it from unrelated bacteria that already have resistance.
> Genetic variation doesn't always come from random mutation.
The article didn't imply it did. It says mutation generates genetic variation, not that all genetic variation is generated by mutation.
A -> B does not imply B -> A
The article didn't imply it did. It says mutation generates genetic variation, not that all genetic variation is generated by mutation.
A -> B does not imply B -> A
I was speaking specifically of this line:
> That genetic variation is generated by random mutation — a process that is unaffected by what organisms in the population want or what they are "trying" to do.
I have nothing against the second half of that sentence.
Perhaps a better explanation was available elsewhere in the article and I missed it. The link originally went to the middle of the page instead of the beginning, so I wasn't taking it in order.
> That genetic variation is generated by random mutation — a process that is unaffected by what organisms in the population want or what they are "trying" to do.
I have nothing against the second half of that sentence.
Perhaps a better explanation was available elsewhere in the article and I missed it. The link originally went to the middle of the page instead of the beginning, so I wasn't taking it in order.
Ah, sorry. Earlier on it gave the version I was responding to. Still I think in science it is better to not assume universal qualifiers unless they are explicit.
This is a good page, but one thing it doesn't touch on (presumably because of the intended audience) is the fact that an understanding of genetics is necessary but insufficient to explain speciation, variation in heritable traits, much of modern biology. Epigenetics is tremendously important, and a reductivist use of genetics via metaphor is what gets people talking about a "gene for X". It ends up, IMO, causing more harm than good.
I think most people have a missconception about the mutation-process, recent research find that it's not very random and environment influences a lot. That is a radical difference from previous evolutionary-biology which was a missconception about the evolution process in itself, the new neo-evolutionary theory is closer to reality.
The old evolution-theory is spread more than other scientific theories primarily because it has inferences onto politics, society and religion. It acts as a scientific narrative of life, most often the information spread is inaccurate according to the theory itself, but it's primarily used to justify politics.
While the old evolution theory had inferences in beginning of 1900 of anti-race, anti-weakness and anti-homosexuality (nazi, racial-biology) after 1970 the inferences instead change to be pro-race, pro-homosexuality (homosexuality is created by evolution for a purpose instead of a error now). The interesting thing is that while the inferences from evolution theory changed, the theory itself was the same, it's just the politics around it that change. Evolution theory is used to support politics as a contemporary narrative. You can pretty much justify anything by creating a purpose of why evolution wanted something to occur, like "The evolution wants us to create babies and progress technology.", "The evolution theory wants women to be better at hearing baby screams."
The new neo-evolution theory instead brings a whole range of new inferences. If the environment can change mutations and progress itself then environment becomes important. Inferences from the old theory was that people were predefined from birth by their biology and this became the basis for many sciences today like psychiatry. When the premises of other sciences become questioned, the sciences need to updated.
Without having a discussion about epistemology I think it's impossible to understand the difference from fact, theory, hypothesis and truth. Just because predictions from a theory is true it doesn't mean that the theory is the truth, it just means that it does accurate predictions. Most of scientific theories have been revised and it would be naive to think that neo-evolution theory is the definitive end definition about evolution.
If evolution-theory would be distributed without inferences on politics I don't think it would be a hot topic at all
The old evolution-theory is spread more than other scientific theories primarily because it has inferences onto politics, society and religion. It acts as a scientific narrative of life, most often the information spread is inaccurate according to the theory itself, but it's primarily used to justify politics.
While the old evolution theory had inferences in beginning of 1900 of anti-race, anti-weakness and anti-homosexuality (nazi, racial-biology) after 1970 the inferences instead change to be pro-race, pro-homosexuality (homosexuality is created by evolution for a purpose instead of a error now). The interesting thing is that while the inferences from evolution theory changed, the theory itself was the same, it's just the politics around it that change. Evolution theory is used to support politics as a contemporary narrative. You can pretty much justify anything by creating a purpose of why evolution wanted something to occur, like "The evolution wants us to create babies and progress technology.", "The evolution theory wants women to be better at hearing baby screams."
The new neo-evolution theory instead brings a whole range of new inferences. If the environment can change mutations and progress itself then environment becomes important. Inferences from the old theory was that people were predefined from birth by their biology and this became the basis for many sciences today like psychiatry. When the premises of other sciences become questioned, the sciences need to updated.
Without having a discussion about epistemology I think it's impossible to understand the difference from fact, theory, hypothesis and truth. Just because predictions from a theory is true it doesn't mean that the theory is the truth, it just means that it does accurate predictions. Most of scientific theories have been revised and it would be naive to think that neo-evolution theory is the definitive end definition about evolution.
If evolution-theory would be distributed without inferences on politics I don't think it would be a hot topic at all
My brain always goes meta when people attack evolution as "just a theory."
I start to think to myself - "Well, you don't understand... New theories are formed all of the time, but the ones that are the most fit survive..."
And then I realize I'm practically using evolution to explain what a scientific theory is, so that the person can understand that evolution is not "just a theory." D'oh!
I start to think to myself - "Well, you don't understand... New theories are formed all of the time, but the ones that are the most fit survive..."
And then I realize I'm practically using evolution to explain what a scientific theory is, so that the person can understand that evolution is not "just a theory." D'oh!
I recently read some HN posts about research to stop aging. Then this.
Makes me curious -- does anyone do research involving some kind of organism with very short generation times, whereby the experimenters attempt to only allow the oldest individuals to reproduce?
The idea would be to apply "artificial selection" that optimizes for longevity.
Does anyone know of any research similar to this being done?
Makes me curious -- does anyone do research involving some kind of organism with very short generation times, whereby the experimenters attempt to only allow the oldest individuals to reproduce?
The idea would be to apply "artificial selection" that optimizes for longevity.
Does anyone know of any research similar to this being done?
The biggest conception about evolution is the question about whether it's true.
But evolution is not true or false it's simply just a model to describe how life evolves, the best model we have.
But evolution is not true or false it's simply just a model to describe how life evolves, the best model we have.
I'm curious if there are any HN readers that don't believe that evolution is the best explanation for the current state of life on this planet (other than me). Any IDers (intelligent design) out there?
[deleted]
People I speak to think its just a theory, hence a guess, a hunch, and not a fact, not proven etc, where as its actually the opposite of that, i.e we can test the predictions it makes, its as close to being proven as anything can be. If people can simply recognize the definition I bet more people can learn and accept Evolution. [2] explains this better.
[1]: http://rationalwiki.org/wiki/Scientific_theory [2]: http://www.notjustatheory.com/