So they've determined that ancient humans used to have barbs on their whoppers (using the Ugandan slang cause I don't know what the plural for penis is). Making us more like cats than dogs! Apparently chimpanzees have these barbs, did not know that. They just aren't too sure what the barbs are really for, like increased stimulation, vag unblockers etc.
Here's the article:
http://www.bbc.co.uk/news/science-e.....nment-12689692