Yahoo News 
We might have worked out why humans don’t have a penis bone, scientists say
It’s a long-standing mystery – why do humans not have a penis bone, whereas some of our closest relatives do?
Other animals have truly magnificent bones down there – with a walrus penis-bone measuring up to two feet.
Some small monkeys have penis bones up to 5cm – but humans have nothing.
Scientists now believe it might be to do with our mating habits – specifically to do with monogamy, and our need (or lack of) for ‘prolonged’ sex.
Animals that have penis bones tend to use them for prolonged mating, while trying to fend off other males and impregnate the female.
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As humans are monogamous (well, ish), we have no need of prolonged mating, the scientists say.
Kit Opie of University College London says, “Despite what we might want to think, we are actually one of the species that comes in below the three minute cut-off where these things come in handy.”
The researchers believe that humans may have lost their penis bones around 1.9 million years ago – when our mating strategy changed.
The researchers write ‘We think that is when the human baculum would have disappeared because the mating system changed at that point.
‘This may have been the final nail in the coffin for the already diminished baculum, which was then lost in ancestral humans. With the reduced competition for mates, you are less likely to need a baculum.’
