Think you have a rough sex life? Try being a female chimp.
The male common ancestor of humans and chimpanzees had spines on their members that likely increased stimulation during mating, according to a new study in the journal Nature. Human males (and Neanderthals) dropped this trait, while chimps kept the spine.
The penis spines, while improving stimulation, can also inflict damage on females during intercourse.
The discovery, made after a detailed comparative analysis of human, Neanderthal and chimpanzee genomes, reveals that both humans and Neanderthals went on a separate evolutionary path from chimpanzees and other primates after humans often paired up into couples.
The finding also bolsters the theory that humans and Neanderthals would have been sexually compatible and likely mated.
“Humans have evolved a more monogamous long-term bonding system, which involves a whole series of anatomical changes,” lead author David Kingsley told Discovery News.