More evidence for evolution. It never ends. But still there are evolution deniers. Especially in Idiot America. It's impossible to be more bloody stupid than an American.

One species splits into two species. It's called speciation. Here is one example of how it could work.

Study Catches Two Bird Populations As They Split Into Separate Species

The first and last paragraphs:

July 30, 2009 — A new study finds that a change in a single gene has sent two closely related bird populations on their way to becoming two distinct species. The study, published in the August issue of the American Naturalist, is one of only a few to investigate the specific genetic changes that drive two populations toward speciation.

That change appears to have been enough to create a reproductive barrier for flycatchers. Not every species is so picky, so a color change doesn't always drive speciation. Nonetheless, these results suggest that it can take as little as one gene, in the right spot in the genome, to cause a fork in the evolutionary road.