One perennial argument used by Creationists is "if evolution happens, why don't we ever see it?" In vain the biologist answers that we've only been systematically observing species for a couple of centuries, and speciation is something which normally takes place on geological timescales.
Well, now there's a better answer: the hawthorn fly. In the four centuries since apples were introduced to North America, one lineage of the native hawthorn fly adapted to the new opportunity and began laying its eggs on apples. The apple flies became genetically distinct from the more traditionalist hawthorn flies.
Better yet, a parasitic wasp which feeds on hawthorn fly larvae has now also diverged and adapted in response to this change in the fly's behavior. So that's potentially two new species originating in response to the introduction of apples to America. Evolution in action.
Thanks! Understanding Evolution is part of basic scientific literacy.
Posted by: Doc P | February 07, 2009 at 10:51 AM
In vain the biologist answers that we've only been systematically observing species for a couple of centuries, and speciation is something which normally takes place on geological timescales.
I've always favored "Shut up, you ignorant, Bible-banging jackass," but I admit it's not usually successful.
Posted by: Molly, NYC | February 08, 2009 at 06:42 AM