Lost DNA led to spineless penis, big brains

Jodi - posted on 03/12/2011 ( 6 moms have responded )

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Big brains and a softer penis are the result of the things we have lost on the evolutionary road, US researchers reveal.

In a paper published this morning in Nature, the Stanford University researchers show the differences between humans and our nearest relative, the chimpanzee, are the result of DNA sequences lost since our divergence from a common ancestor about 6 million years ago.

Women of the world will be particularly grateful that among the ditched DNA is the penile spine enhancer, which gives chimpanzees spiky-spined penises.

Co-author Professor David Kingsley, of the Howard Hughes Medical Institute at Stanford University, says the loss of the "intimidating" penile spines could be a factor in humans developing monogamous relationships.

It is believed in chimpanzees and other mammals penile spines are used, among other things, to sweep away competing sperm.

"Organisms that have penile spines generally have a competitive mating system," says Kingsley.

"Females advertise when they are fertile and females are only sexually receptive around ovulation.

"In humans ovulation is hidden in females and the female in our species is sexually receptive for an extended period of time. [The loss of the penile spines] is part of a whole suite of changes related to longer-term bonding and not brief encounters."

http://www.abc.net.au/science/articles/2...

So, does this now make the argument that men were not MEANT to be monogomous creatures redundant?

This article just made me giggle, especially given all the jokes we women make about the balance of the male brain and where it may reside at various times :P I thought you girls may find it interesting too.

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Lacye - posted on 03/13/2011

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Yay! No spikey penises! I swear to god if men still had them, I would convert and become a Catholic just so I could be a nun!

Jocelyn - posted on 03/13/2011

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Whatever the reason, I'm really glad they don't have spines anymore. Sheesh.

Bigger brains are debatable.

[deleted account]

I thought the spines were to prevent another male from detaching the couple too early in case of a fight over the female.

Sharon - posted on 03/12/2011

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When I heard about penile spines, I thought maybe they were to cause a female pain so she wouldn't want to have sex with anyone else and therefore protect the sperm.

Amanda - posted on 03/12/2011

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Interesting theory, I was always under the impression for the penis spines is so when the male finishes his job up, as he leaves the female the pain tells her body to ovulate. Shurgs.

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