Sunday, October 10, 2010

Evidence is Just an Evolutionary Presupposition

Answers in Genesis has an article today on "Trace Your Family History through DNA Testing."  Most of the article is taken up in discussing why and what your DNA can tell about your ancestors if you have a hundred dollars to spare and the curiosity to spend it this way.  But they do not, of course, neglect the creationist angle.
Like many modern geneticists, Wells starts with the assumption that we all came out of Africa after humans branched off from their ape-ancestors approximately 5 million years ago. However, the Bible tells us that we were created in the image of God about 6,000 years ago and that the human population dispersed from Babel with many likely settling in Africa. ...  Genesis 11 tells us the rest of the story—we came out of Babel, not out of Africa.
Now, this is one of my pet peeves with creationists: the conflation of "assumptions" (or "presuppositions") with "conclusions."  There are assumptions at work, of course (though these are based based, in turn, on the way inheritance, mutation, and genetic drift are observed to work): that, e.g. the area of greatest genetic diversity is probably where a species has been the longest.  Thus, e.g. silkworms are found, unsurprisingly, to be most genetically diverse in China, where they originated and were first domesticated.    Note that this assumption does not in any way depend on the assumption that humans share ancestry with any other species.  By itself, it does not depend on the assumption that the human species is a couple of hundred thousand rather than six thousand years old.  Indeed, it does not even depend on the assumption that geneticists are wrong right about the rate at which neutral mutations accumulate through random drift.

If human beings had dispersed from "Babel" (presumably in what is now Iraq), then we would certainly expect to find that the greatest variety of mitochondrial DNA was concentrated in southwest Asia, since humans had lived there longest and their local gene pools had had the longest time for mutations to occur and spread.  We would expect sub-Saharan Africa to show no more variety than, say, Australia or North America.  Of course, it's conceivable that not merely "many" but the overwhelming majority decided, when they scattered from Babel, to travel en masse down the Nile and into sub-Saharan Africa (though it would be hard to coordinate the march, given the miraculous confusion of languages that occurred earlier in that chapter).

Explicit young-earth creationists are even more explicit than ID proponents in asserting that reliance on evidence is just an arbitrary and even anti-theistic bias.

5 comments:

  1. Indeed, it does not even depend on the assumption that geneticists are wrong about rate at which neutral mutations accumulate through random drift.

    ...are right about the rate?

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  2. Yes, thank you, that was what I meant. Someday, I'm going to have to start proofreading these articles before I post them.

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  3. If human genealogy in the bible is correct, all males post flood had identical Y chromosomes. How does AiG account for the diversity and distribution of the Y chromosome that geneticists see today? Ancestry.com claims you can learn the story of your most ancient paternal ancestry from up to 100,000 years ago. I suppose they are laughing all the way to the bank. How does AiG explain the fact we do not see signs of a bottleneck 4-5 thousand years ago?

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  4. Milo replied to me:

    If human genealogy in the bible is correct, all males post flood had identical Y chromosomes. How does AiG account for the diversity and distribution of the Y chromosome that geneticists see today? Ancestry.com claims you can learn the story of your most ancient paternal ancestry from up to 100,000 years ago. I suppose they are laughing all the way to the bank. How does AiG explain the fact we do not see signs of a bottleneck 4-5 thousand years ago?

    I'm not sure they do. I would suppose, based on their past answers to comparable questions, that they would say something like "evolutionists and creationists have different presuppositions about how fast natural processes can work. As humans spread out from Babel, and lifetimes were drastically shortened due to climate changes post-flood, different populations lost different genetic information from various genes, causing this haplotype differences."

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  5. Creationists baffle me in their seemingly proud ignorance. They waive evidence in favour of bible myths, and they don't even have a comprehensive, correct understand of their own bible. I'm an atheist, and I know a hell of a lot more about Christian theology than any of these cretins at AiG, DI or CMI. It may have something to do with the fact that I only left the church 18 months ago, and have many friends and family members that are theologians and pastors (or studying to become one), but hey, the information isn't exactly hard to find.

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