Monday, July 11, 2011

Genetic Similarity

Today I want to point out another problem with the appeal to genetics as support for evolution. This part of the claim...
DNA profiles show evolutionary relationships among species.
involves circular reasoning. Genetic similarity is offered as proof for evolution, but only because the claimant assumes that any similarity must be due to evolution. This is, of course, fallacious.

The evidence, stated without bias, is that all living things share varying degrees of similarity, both in their biochemical composition and in their genetic make-up. The degree of similarity tends to increase within recognizable hierarchies, such that mammals are more similar to one another than any mammal is to birds, and primates are more similar to one another than any primate is to bats or whales. That this is true at the morphological level has been known for a long time. The ancient Greeks understood it (and, I dare say, so did most ancient peoples). It certainly was well-known prior to Darwin, as by his time comparative anatomy was a well-developed discipline.

As I shared in the last post, Darwinists expected this similarity NOT to be true at the molecular (biochemical level), and they were wrong. We now know that this hierarchy of similarity extends (generally) to the genetic level.

But again, this recognition utterly fails to distinguish among competing theories for the diversity of life. Specifically, the alternate view that has been held for the vast majority of the history of Western civilization--that there is a single Creator/Designer responsible for life--finds at least equal support from these findings from the latest genetic research. Indeed, the great similarity (on the levels of morphology and physiology, biochemistry, and genetics) between living things actually presents problems for Darwin's theory. This includes the highly-publicized finding that chimps and humans share 95% or more of the same genetic material.

You see, Darwin's theory was not an attempt to explain the similarities between living things. Rather, it was an attempt to explain the differences. Gradualistic evolution--with its vast number of hypothetical (and yet-undiscovered) transitional forms--was meant to explain how the differences (as between chimps and humans) came to be. And that explanation involved strictly material causes and effects. That is, if evolution is an accurate explanation for the diversity of life, we will discover differences (at some level, whether biochemical, genetic, embryological, or whatever) that represent sufficient causes for the morphological, physiological, and other obvious differences.

Instead, at each material level (first biochemistry, then genetics, now evo-devo) evolutionary scientists are surprised at how similar different organisms (like chimps and humans) are. In other words, we still cannot say--on strictly materialist terms--what accounts for the vast differences (especially on characteristics like intelligence, reasoning, imagination, and such) between us and chimps. The genetic evidence doesn't account for these differences--and so, far from supporting evolution (as is frequently claimed), that evidence further undermines naturalistic evolution as an adequate explanation.

To believe otherwise is simply to argue in a circle.

(This post first appeared here on 7 June 2008, but remains relevant today.)

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