ScienceDaily (Sep. 29, 2010) — The yellow monkeyflower, an unassuming little plant that lives as both a perennial on the foggy coasts of the Pacific Northwest and a dry-land annual hundreds of miles inland, harbors a significant clue about evolution.
Duke graduate student and native northern Californian David Lowry had become interested in how a single species could live such different lifestyles. He set out to find a gene or genes that would account for the monkeyflower (Mimulus guttatus) being a lush, moisture-loving, salt-tolerant perennial on the coast, but a shorter, faster-flowering, drought-tolerant annual inland.
What he found instead was that a large chunk of the plant's genome -- 2.2 million letters of DNA and 350 genes -- are working differently in each ecotype of the plant. The difference is called a genetic inversion, a long piece of DNA that has been clipped out of a chromosome at both ends and then reinserted essentially upside down.
http://www.sciencedaily.com/releases/2010/09/100928171434.htmParagraph for Christine O'Donnell:
Inversions are particularly interesting to biologists who are trying to figure out how one species becomes two. Notably, many significant inversions have been identified between humans and chimpanzees. And one of Lowry's Duke advisors, biologist Mohamed Noor, has found inversions help separate new species of fruitflies.