Monday, December 25, 2006

10 Truths About Atheism

 
From yesterday's Los Angeles Times: 10 myths—and 10 truths—about atheism by Sam Harris.

I'd like to express my disagreement with #4 "Atheists think everything in the universe arose by chance." Harris says,
The notion that atheists believe that everything was created by chance is also regularly thrown up as a criticism of Darwinian evolution. As Richard Dawkins explains in his marvelous book, “The God Delusion,” this represents an utter misunderstanding of evolutionary theory. Although we don’t know precisely how the Earth’s early chemistry begat biology, we know that the diversity and complexity we see in the living world is not a product of mere chance. Evolution is a combination of chance mutation and natural selection. Darwin arrived at the phrase “natural selection” by analogy to the “artificial selection” performed by breeders of livestock. In both cases, selection exerts a highly non-random effect on the development of any species.
That's not quite right.

Nobody denies the power of natural selection and nobody claims that natural selection is random or accidental. However, the idea that everything is due to natural selection is the peculiar belief of a relatively small number of people, of whom Richard Dawkins is the most outspoken.

A great deal of evolution is the result of chance or accident, as is a great deal of the rest of the universe. It's perfectly okay to say, as a first approximation, that lots of evolution is random or accidental. This is a far closer approximation to the truth than saying it's the all the result of design by natural selection.

See Evolution by Accident. As far as I'm concerned, it's Harris and Dawkins who represent an "utter misunderstanding of evolutionary theory."

8 comments :

  1. I don't think Dawkins holds a position that everything in evolution is due to natural selection. He may not
    consider genetic drift as important as you do but he certainly sees that there is genuine controversy about it. In an article about ID he lists natural selection vs genetic drift one of the real controversies in evolutionary biology:

    Natural selection is a process that leads to the replacement of one gene by another in a predictable way. But there is also a "random" evolutionary process called genetic drift, which is the genetic equivalent of coin-tossing. Genetic drift leads to unpredictable changes in the frequencies of genes that don't make much difference to the adaptation of their carriers, and can cause evolution by changing the genetic composition of populations. Many features of DNA are said to have evolved by genetic drift. Evolutionary geneticists disagree about the importance of selection versus drift in explaining features of organisms and their DNA. All evolutionists agree that genetic drift can't explain adaptive evolution. But not all evolution is adaptive.

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  2. And in a much broader sense, biology is the result of basic physical laws, such as the properties of carbon and water.

    Of course, Intelligent Design advocates don't even have a reasonable grasp of what 'chance' means. Even though lottery balls work by well-known physical laws, we still consider the lottery a game of chance and lottery winners to be lucky.

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  3. Anonymous says,
    I don't think Dawkins holds a position that everything in evolution is due to natural selection.

    This is correct. Dawkins is smart enough to realize that "natural selection" and "evolution" aren't always synonyms. That is, he's smart enough to realize it when he's forced to, but that doesn't happen very often. In most cases he's not paying attention and he slips into his normal worldview where "natural selection" is a synonym for "evolution."

    Dawkins' believes that adaptation is the only interesting part of evolution and he believes that almost all of the visible part of evolution is the result of natural selection. He's just not interested in anything but adaptation and he doesn't think we should be either.

    It's quite reasonable to call Dawkins a Darwinist and he doesn't mind it at all. Pluralists, like me, on the other hand, resent being lumped in with the old-fashioned, pan-adaptationist Darwinists.

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  4. Chance or accidental?

    I disagree heartily with that, although maybe it's largely semantics. I am of the view that the words "stochastic" or "non-deterministic" are more appropriate. Even "statistical" is a useful word here.

    I take issue with the word "chance" or "random" largely because it doesn't do justice to the physical/chemical rules that constrain non-adaptive evolution, genetic drift, neutral theory, etc.

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  5. I prefer "accident" because the words "chance" and "random" are loaded with meanings and seem to provoke semantic wars whenever they are used.

    The main point is that if you replay the tape of life it will probably come out very differently. To me, that means there's a significant "accident" component in evolution. This point often gets lost in conversation.

    Creationists often accuse us of believing that evolution is "random." That doesn't bother me very much. It conveys the idea that life is not designed and has no purpose. I think that's an accurate representation of evolution.

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  6. The main point is that if you replay the tape of life it will probably come out very differently.
    That's something I'm very curious about - and to be sure, the details of life's history would likely come out differently, but I imagine that general themes would likely replay themselves, owing the properties of complex systems (Christoph Adami's work with digital organisms comes to mind). Sean B. Carroll also seems to make this case in Endless Forms Most Beautiful, that in evo-devo, modularity in genetics and development facilitate the evolution of similar forms again and again. The example that Carroll uses, and has stuck in my head, is that of flight - the three unique but comparable ways in which forelimbs evolved into wings for pterodactyls, bats, and birds.

    It conveys the idea that life is not designed and has no purpose. I think that's an accurate representation of evolution.

    Alas, again, I must disagree. I think that life's intricate structure/function relationship does reflect design and purpose, just that the creationists hijack those terms to their own superstitions. Maybe I just have too much of The Blind Watchmaker on the brain, but I think that the purpose of life is to propogate itself, and that pragmatic forces drive the selection of design, including the natural arisal of complexity, robustness, modularity, weak linkages, exploratory behavior, and feedback mechanisms.

    But I know you're not discounting such adaptive molecular phenomena, you're just reinforcing the stochastic element to this. What we have a hard time explaining to the public, I think, is that all of this - adaptive determinism and stochastic drift - is at work. For such complexity and chemical detail, it's tough to get laypersons to wrap their heads around it.

    It's just such a shame that many of these words have become so laden with political implications. Semantics just make it so confusing, such that while I'm pretty sure you and I are on the same page here, we end up disagreeing about how it's worded.

    Anyway, thanks for providing a forum to mention these fascinating topics.

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  7. "Although we don’t know precisely how the Earth’s early chemistry begat biology"

    That's an understatement if there ever was one.

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  8. I do think that we should step back and ask broader questions. The original point “it is all by chance” was not about life, but rather it was a more general statement about life, the universe, and everything. (...right... 42 ...).

    I think we can say that it is a great interest to scientists and lots of other people to understand causality. Causality is always there. Causality is the verb in the sentence that is any particular thing that happens. Causality is not separate from or different from randomness, chance, accident, etc. and causlity needs to be (or should I say provides the opportunity to be) examined at many levels (i.e., the usual Tinbergian levels such as mechanistic, developmental, and so on).

    I agree completely with Laurence Moran that the original statement is wrong. Athiests are typically interested in analysis and free thinking. Indeed, item # 4 exactly oppostiely cahracterizes typical atheistic thinking ... atheists are interested in understanding causality. Why would atheists presume that the answer to the ultimate question (about life, the universe, and everything) would be known at this moment in time?

    With respect to evolution of life in particular, well, for that we have Evolutionary Biology, and there is not a simple paradigm there regarding randomness vs. whateverness. The present form and pattern of life on this planet is not something that can be described with one word. Randomness and selection are two words that hit on some major point, and it would be wrong of course to choose between them!

    Regarding: “The main point is that if you replay the tape of life it will probably come out very differently.
    That's something I'm very curious about - and to be sure, the details of life's history would likely come out differently, but I imagine that general themes would likely replay themselves,” (Dan Rhoads)

    Right, the tape can never be the same, but on this planet, you just know stuff will evolve to fly, to be woodpeckers, to swim, etc. etc. There is a general pattern.

    GTL
    gregladen.com

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