Nalini Nadkarni of Evergreen State College currently advises a team of researchers who sport shaved heads, tattooed biceps and prison-issued garb rather than the lab coats and khakis typically worn by researchers.

If you own a birdbath, chances are you're hosting one of evolutionary biology's most puzzling enigmas: bdelloid rotifers. These microscopic invertebrates-widely distributed in mosses, creeks, ponds, and other freshwater repositories-abandoned sex perhaps 100 million years ago, yet have apparently diverged into nearly 400 species. Bdelloids have remained an enduring enigma in part because biologists are still debating whether the species actually exist as true evolutionary entities.