PLoS Biology has an article out today entitled: “Hotspots of Biased Nucleotide Substitutions in Human Genes”. I’ve mentioned this ‘biased’ substitution pattern before. What the authors see, they tell us, is a definite W->S substitution pattern in human genes (Weak to Strong = A:T->C:G) against an overall pattern of S->W; for the entire human genome. This is part of their summary:
Our findings are consistent with a model of recombination-driven biased gene conversion. This leads to the provocative hypothesis that many of the genetic changes leading to human-specific characters may have been prompted by fixation of deleterious mutations.
What the authors report is a non-random shifting within genes, and the introduction of “deleterious” mutations. Neither of these is consistent with Darwin. Darwin said that if it could be shown that any change in an organism was harmful, then his theory would be overturned.
I’ll let you reach your own conclusions. Here’s the link.