Saturday, July 28, 2012

Dennis Venema Begs the Question and Warns the Church That it Must Come to Terms With Human-Chimp Common Ancestry

In spite of the crystal clear message from science that evolution is not a good hypothesis evolutionists continue to add confusion and uncertainty to promote their mythology. One tactic evolutionists use is to interpret evidence in terms of evolution and then claim the result as evidence for evolution. That is not only bad science, it is fallacious. Conclusions cannot also be premises. Yesterday’s installment from evolutionist Dennis Venema is yet another example of this never ending display of petitio principia.

Venema reviews a recent paper by other evolutionists who say they have found evidence of natural selection acting on random mutations to help change a population of small primates into humans. Venema tells us that such findings are “elegant and powerful” and that they “powerfully support the common ancestry of humans with other forms of life, such as chimpanzees and other great apes.”

So did the study that Venema reviews really find such evidence of random mutations and natural selection miraculously bringing about such incredibly unlikely changes? The paper mentions “selection” 56 times, over and over claiming to have found signs of positive selection. One could be excused for having the impression that this is a solid scientific finding.

And the paper’s explanation for how it made such an amazing discovery is fairly technical and not accessible to the non specialist. This is where Venema, a specialist writing for a broad audience, could have helped. Instead he further obfuscated the implications of the study.

Very simply put, while there are many ways evolutionists test for positive selection, they all take evolution as a given. It is not possible simply to measure objectively the selection in DNA as one would, for instance, measure the voltage or current in a circuit using a multimeter.

For example, one strategy evolutionists use to test for selection is to (i) compare the DNA sequences from several species including humans, (ii) derive the corresponding DNA sequence of the common ancestor of those species, (iii) find the changes in the human DNA compared to the common ancestor, (iv) conclude that those human DNA regions with relatively large change are under positive selection and that those regions with relatively little change are under negative, or purifying, selection.

Notice that the second step implicitly assumes there is a common ancestor. And likewise the third step assumes the species evolved from that common ancestor. And so consequently the fourth step concludes that DNA regions with greater differences probably underwent positive selection. The conclusion is based on the presupposition that evolution occurred.

Venema, as a specialist, knows all this. He knows the entire project presupposes evolution. Yet he tells us that the results powerfully support common ancestry and that the church must come to terms with such findings. The irony is that the presupposition of evolution originally came from theological convictions. Venema is simply promoting a centuries old religious mandate which science has repeatedly contradicted. Now evolutionists such as Venema cast themselves as scientists informing the church of new, important findings. Religion drives science and it matters.