Tiny, Transparent Worm Challenges Notions About Sex

Tiny, Transparent Worm Challenges Notions About Sex
When it comes to sex, the roundworm Diploscapter pachys is a loner.

Scientists have found a group of worms that haven't reproduced sexually for 18 million years. Normally that would be a recipe for quick extinction, but these little guys seem none the worse for wear.

(Image credit: Courtesy of Karin Kiontke and David Fitch/ NYU)