Although humans and chimpanzees share 97% of the same DNA, there are some BIG differences.
Two include our brain and penis, but did you know chimps have penis spines!?
Not like fish or porcupine spines, but small bumps on the organ, which scientists speculate may have been used to aid in sperm competition.
The male chimpanzee's goal is to get his mate pregnant and its bumpy penis may be used to take out the partners sperm if she has recently had sex.
Kind of a gross visual, we know, but after studying human and chimpanzee genome and androgen receptors, scientists theorize our earliest human ancestors probably shared this trait five to seven millions of years ago before we split off into separate species.
Due to millions of years of very kind evolution, humans eventually lost this genome that causes this trait and thanks be to God (who may or may not have anything to do with it) because we'd hate to have prickly peen.
While scientists can only credit natural selection, we're assuming this is how the change went down:
Ancient Early Human Woman: Ew…what are those things? They kind of hurt.
Ancient Early Human Male: My penis bumps. Everyone has them.
Ancient Early Human Woman: That guy doesn't.
Ancient Early Human Woman walks away toward other Ancient Early Human Male named Carl with no penis bumps.
Ancient Early Human Male: Dang it!
[Image via WENN.]