I ran across this letter at New Scientist and thought that it called out an interested aspect of an argument used by ID and creationists against Evolution.
Charles Young’s call for photographs of the most complete progression from one species to another to illustrate evolution (5 April, p 21) highlights two interesting issues when considering the evolution/creationism controversy.
In his online battle with creationists who demand evidence for the existence of transitional evolutionary forms, Young seems to have fallen foul of their variation on Zeno’s paradox. In its original form, this appears to demonstrate that walking from one side of a room to the other is impossible if one tries to do it “mathematically”. By walking half the distance, then half the remaining distance, then half that remaining distance and so on, you will never reach the other side.
When creationists demand not just the broad sequence of transitional forms that led, for example, from land-based mammals to whales, but also every conceivable “in-between” form, they know they are asking the impossible. That’s not because evolution of the whale didn’t happen as described, but because of the statistical impossibility that each and every stage would be fossilised and then found – fossilisation is, after all, a rare event – and a simplistic view of evolutionary change as only ever taking place in small, incremental steps in each and every species. Adding transitional forms simply increases demands from creationists. They will claim that instead of filling a gap, the new fossil actually creates new gaps before it and after it, thereby increasing the problem for the evolutionist. If we then “fail” to fill these new “gaps”, they cry victory.
Nevertheless, Young’s call for better, more robust examples to be made more available is a valid one. Sadly, textbook writers are somewhat lazy in simply using the old favourites of the horse and peppered moth. Your feature by Donald Prothero (“Evolution: What missing link?” 23 February, p 35) nicely illustrated the range of well-evidenced transitional forms. These are the examples that should adorn our textbooks.
Being a breeder of African cichlids, I’d recommend them as the “poster fish” of Evolution.