Following up on his excellent message on why science and faith don’t need to be at war, Peter Gorham passed this story along about a new finding that illustrates how much more complex our world is than either rabid Darwin fanboys or hysterical fundamentalists would like to believe:
It’s a miracle! Blind cavefish, despite having adapted to their lightless environment for more than a million years, can produce sighted offspring in just a single generation, a new study reveals.
The ability was discovered when researchers mated fish from distinct populations that had been isolated in separate caves. In some cases the first-generation offspring of such unions could see.
Peter’s comment:
The most interesting thing about this is not that an eye can reappear after one generation in an otherwise blind fish, because there are many examples where dormant genes are switched on due to environmental stress factors. However, that usually happens over the timescale of a small number of generations of a critter, so that the gene is re-expressed periodically and then gets its functionality “pruned” by natural selection.
In this case, the eye has apparently been dormant, hidden in the genes for millions of years according to the article, and there is thus no way to use natural selection to argue that the mutations in that portion of the genome can be properly pruned in an ongoing manner. A complex organ like the eye requires probably 10-100 genes to encode, implying probably at least 1 million base pairs of DNA involved. Net mutation rates (accounting for species fertility) are typically about 1 per 10-100 million per base pair generation, and are higher in dormant genetic material which is not corrected by natural selection. Gene codes become non-functional and unrepairable at typically a few percent total mutations. In the very best case these dormant eye genes must exceed a 10% total mutation content per million years, so it appears that after a million years the dormant eye would no longer be viable by a pretty wide margin. This implies another mechanism beyond natural selection is needed to maintain and repair these dormant codes until they are needed.
I would say this example has not yet absolutely demonstrated the need for a new mechanism, but it really stretches the limits of natural selection as posited.
For some reason, I think this is the level God will always keep our scientific knowledge at – just enough evidence to make his existence and work probable, but no slam-dunk proof that removes the need for at least a little stretch of faith.
It seems to me that when God makes himself more evident (ie manifesting himself as a pillar of fire in the desert), people actually respond with less trust and obedience (ie demanding to go back to Egypt to be slaves again).