How birds lost their penises

Thursday, June 6, 2013 - 13:51 in Biology & Nature

KRISTEN BUTLER, UPI.com Most male birds lost their penises to evolution, and a new study shows why they stop growing and wither away.

Read the whole article on UPI

More from UPI

Learn more about

Latest Science Newsletter

Get the latest and most popular science news articles of the week in your Inbox! It's free!

Check out our next project, Biology.Net