When it comes to whales and dolphins, certain bones seem to serve little to no purpose. Their hip bones, in particular, look as if they're just evolutionary remnants from when they used to walk on land. Now, though, scientists have found that these pelvic bones may be crucial when it comes to sex.
"Everyone's always assumed that if you gave whales and dolphins a few more million years of evolution, the pelvic bones would disappear," said Matthew Dean, one of the researchers, in a news release. "But it appears that's not the case."