Thursday, April 17, 2008

Evolution: 24 myths and misconceptions

 
If you think you understand it, you don't know nearly enough about it.
New Scientist has just published an excellent series of articles on evolution [Evolution: 24 myths and misconceptions]. These are some of the best explanations of evolution that I've ever seen in a popular magazine. Thus, it's all the more tragic that they spoil it all by putting a false picture of evolution (right) on the website.

Shared misconceptions:

Everything is an adaptation produced by natural selection
We tend to assume that all characteristics of plants and animals are adaptations that have arisen through natural selection. Many are neither adaptations nor the result of selection at all.
Natural selection is the only means of evolution
Much change is due to random genetic drift rather than positive selection. It could be called the survival of the luckiest.
Natural selection leads to ever-greater complexity
In fact, natural selection often leads to ever greater simplicity. And, in many cases, complexity may initially arise when selection is weak or absent.
Evolution produces creatures perfectly adapted to their environment
You don't have to be perfectly adapted to survive, you just have to be as well adapted as your competitors. The apparent perfection of plants and animals may be more a reflection of our poor imaginations than of reality.
Evolution always promotes the survival of species
The phrase "survival of fittest" is widely misunderstood (see 'Survival of the fittest' justifies everyone for themselves). Many wrongly assume it means that evolution always increases the chances of a species surviving.

Evolution sometimes results in individuals or populations becoming less fit and may occasionally even lead to extinction.
It doesn't matter if people do not understand evolution
At an individual level, it might not matter much. However, any modern society which bases major decisions on superstition rather than reality is heading for disaster
"Survival of the fittest" justifies "everyone for themselves"
The "fittest" can be the most loving and selfless, not the most aggressive and violent. In any case, what happens in nature does not justify people behaving in the same way
Evolution is limitlessly creative
It might seem like there is no end to nature's inventiveness but there are some features that could probably never evolve, at least on Earth.
Evolution cannot explain traits such as homosexuality
There are numerous evolutionary mechanisms that might explain homosexual behaviour, which is common in many species of animals.
Creationism provides a coherent alternative to evolution
The only thing that creationists agree on is that they don't like evolution. Even Genesis gives two contradictory accounts of creation.

Creationist myths:

Evolution must be wrong because the Bible is inerrant
This argument is undermined by the hundreds of errors and inaccuracies and contradictions found in Bible. It is anything but "inerrant".
Accepting evolution undermines morality
Actually people in more secular countries appear to behave more morally. And even if this claim was true, that would not alter the facts or justify their suppression.
Evolutionary theory leads to racism and genocide
Darwin's ideas have been invoked as justification for all sorts of policies, including some very unpleasant ones. But evolutionary theory is a descriptive science. It cannot tell us what is right and wrong.
Religion and evolution are incompatible
There are various ways in which the known facts about evolution can be reconciled with theistic religions. Some of these ways might be illogical and irrational, but they are no more illogical and irrational than other aspects of religions.
Half a wing is no use to anyone
Just as objects designed for one purpose can be used for another, so genes, structures and behaviours that evolve for one purpose become adapted to do another.
Evolutionary science is not predictive
It might not be possible to predict exactly what life will look like in a billion years but what counts are the predictions that can be made.
Evolution cannot be disproved so is not science
There are all sorts of findings and experiments that could have falsified evolution. In the century-and-a-half since Darwin published his theory, not one has.
Evolution is just so unlikely to produce complex life forms
By weeding out harmful mutations and assembling beneficial ones, natural selection acts like an "improbability drive" that can, given enough time, produce results that appear utterly impossible at first glance.
Evolution is an entirely random process
No and yes. Natural selection is a rigorous testing process that filters out what works from what doesn’t, driving organisms to evolve in particular directions. However, chance events play a big role too.
Mutations can only destroy information, not create it
Biologists are uncovering thousands of examples of how mutations lead to new traits and even new species. This claim not only flies in the face of the evidence, it is also a logical impossibility.
Darwin is the ultimate authority on evolution
Modern evolutionary theory is built on some - but not all - of Darwin's ideas, but has gone far beyond them.
The bacterial flagellum is irreducibly complex
Actually, flagella vary widely from one species to another, and some of the components can perform useful functions by themselves. They are anything but irreducibly complex.
Yet more creationist misconceptions
Evolution is just a theory: Yes it is, like Einstein's theory of special relativity. By theory, scientists mean an explanation backed by evidence. What creationists mean is that evolution is just a hypothesis, unsupported by evidence - which it is not. Evolution is a fact as well a theory.
Evolution violates the second law of thermodynamics
The second law of thermodynamics states that entropy, a measure of randomness, cannot decrease in a closed system. Our planet is not a closed system.


9 comments:

  1. Hi Larry, I'm glad you like the special.

    I understand your point about the picture - but what better way to illustrate a special on myths and misconceptions than with one of them?

    Great blog, btw.

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  2. Thanks for pointing this out Larry.

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  3. My historical geology professor introduced evolution by saying, "Evolution isn't about survival of the fittest; it's about survival of the fit enough." Then he went on to explain what that meant. It was good way to make students think about that old phrase, and learn what it really meant.

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  4. Hi,

    "Actually people in more secular countries appear to behave more morally."

    Erm ... well ... before I agree or disagree with this statement, I'd like to know how one would set about defining what is "more moral" and what evidence there is in support of it.

    One person's morality is another person's horror. Mohammed Atta, for example, could be seen as a very moral person, very devout and religious, etc. For obvious reasons, he could also be seen as a mass-murderer, which is the interpretation I favor.

    I'm not trolling or disagreeing ... I'm just not sure what this statement means or how it can be evaluated objectively.

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  5. "...flagella vary widely from one species to another, and some of the components can perform useful functions by themselves. They are anything but irreducibly complex."

    I think this is the wrong approach here. It was Hermann Muller who first outlined the notion of irreducible complexity, and plenty of biological systems are irreducibly complex by Behe's definition. Behe's not wrong about irreducible complexity; he's wrong about the value of his personal incredulity regarding the generation of such things by natural means.

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  6. For a quick summary on the differences between Muller's "interlocking complexity" and Behe's "irreducible complexity" (one can get a sense of the difference in viewpoints just from the difference between the terms "interlocking" and "irreducible"), see http://www.talkorigins.org/origins/postmonth/sep06.html

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  7. SFMatheson says,

    Behe's not wrong about irreducible complexity; he's wrong about the value of his personal incredulity regarding the generation of such things by natural means.

    I agree. Lots of things are irreducibly complex—like the citric acid cycle. Behe is wrong to think that irreducibly complex things can't evolve. We know how most of them evolved.

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  8. Larry, thanks for the post. I use links like these to educate myself and my friends about evolution and religious thought.

    Bruce

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  9. Well, my biology teacher in high school told us that fittest is not necessarily the strongest or fastest, but that in biology it means "being able to produce offspring", and that anything that lets you do that can become an adaptation.

    When he sais that, it made perfect sense to me; I don't know why so many people don't get it.

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