Part 6 of former YEC David MacMillan's series on how the YEC mind deceives itself when confronting the evidence for evolution is up at Panda's Thumb. This time, he looks at how the YEC tries to explain away the genetic evidence. As I've explained repeatedly, along with biogeography, this provides some of the most compelling evidence for the reality of common descent, and the special creationist attempts to explain it away are frankly pitiful.
The 'common design' explanation is frequently cited in an attempt to explain away the evidence. Ignoring the fact that the multiple shared identical genomic 'glitches' such as pseudogenes, retrotransposons, and endogenous retroviral elements make the case for common descent unassailable:
[t]he obvious problem is that common design is unfalsifiable. There’s no limit to what it can explain, no level of commonality it cannot be used with. We recognize that an explanation which can fit literally anything is useless; it doesn’t tell us anything. Unfortunately, creationists don’t care whether their explanations are falsifiable. Their presuppositionalist background tells them that it doesn’t matter whether explanations are falsifiable – it’s just necessary to make sure they have the right presupposition at the outset, and everything else flows from that. As long as their denial of mainstream science seems vaguely plausible, they are okay.
So instead of pointing out the unfalsifiability of common design, it’s better to let them use it, but challenge them to take it to its logical conclusion. If their divine common design can really produce the observed levels of genetic similarity, then it should also produce clear and obvious genetic similarities in species that aren’t anywhere close on the evolutionary tree. Not just small sequences in common, but entire gene suites. If God is in the practice of re-using the exact same gene sequences in creatures that happen to show up close together, then we should see the same thing in distant species. Species identified in mainstream science as examples of convergent evolution – the same traits or abilities having evolved separately – should have perfectly matching gene sequences placed there by the creator. For example, bats and birds evolved echolocation separately using different genes, but the “common design” argument would predict the same exact gene sequences.Full article is here.
