How The Human Penis Lost Its Spines

Photo: Snowyowls (CC)

Photo: Snowyowls (CC)

When I read that headline I thought I must have clicked on National Enquirer or something, but no, it’s Elizabeth Landau cranking out an SEO-friendly story for CNN:

You’ve read the headline, and it probably made you giggle. Go ahead. Get it out of your system. Then take a deep breath and consider how evolution affected a few specific body parts, and why.

Humans and chimpanzees share more than 97% of DNA, but there are some fairly obvious differences in appearance, behavior and intellect. Now, scientists are learning more than ever about what makes us uniquely human.

We know that humans have larger brains and, within the brain, a larger angular gyrus, a region associated with abstract concepts. Also, male chimpanzees have smaller penises than humans, and their penises have spines. Not like porcupine needles or anything, but small pointy projections on the surface that basically make the organ bumpy.

Gill Bejerano, a biologist at Stanford University School of Medicine, and colleagues wanted to further investigate why humans and chimpanzees have such differences. They analyzed the genomes of humans and closely related primates and discovered more than 500 regulatory regions — sequences in the genome responsible for controlling genes — that chimpanzees and other mammals have, but humans do not. In other words, they are making a list of DNA that has been lost from the human genome during millions of years of evolution. Results from their study are published in the journal Nature.

Think of it like light bulbs and their switches, where the light bulbs are genes and the switches are these controlling DNA sequences. If there’s no bulb, the switch can’t turn the light on. Now imagine there’s one bulb and five switches to turn it on at different times in different places. If you take one of the switches away, the bulb still works in the four other contexts, but not in the fifth…

[continues at CNN]

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8 Responses to How The Human Penis Lost Its Spines

  1. Anonymous March 10, 2011 at 4:21 pm #

    For her pleasure…..ask your plastic surgeon about bumpy-dick implants now……

  2. GoodDoktorBad March 10, 2011 at 12:21 pm #

    For her pleasure…..ask your plastic surgeon about bumpy-dick implants now……

    • A1874185 March 10, 2011 at 5:50 pm #

      and all this time I thought they were warts ;P

  3. Anonymous March 10, 2011 at 4:39 pm #

    Human DNA sequences might be very similar to the chimp, but the two cannot cross-breed, because Human chromosome #2 is in two parts in the chimp. Big difference. This is interesting: http://www.youtube.com/watch?v=IgvqZixAzm4

  4. Anonymous_Reader March 10, 2011 at 12:39 pm #

    Human DNA sequences might be very similar to the chimp, but the two cannot cross-breed, because Human chromosome #2 is in two parts in the chimp. Big difference. This is interesting: http://www.youtube.com/watch?v=IgvqZixAzm4

  5. A1874185 March 10, 2011 at 9:50 pm #

    and all this time I thought they were warts ;P

  6. Renehto March 11, 2011 at 3:09 am #

    I wonder what scenario brings a scientist to feel a chimp’s ridged dick and conclude that there is significance.. .

  7. Renehto March 10, 2011 at 11:09 pm #

    I wonder what scenario brings a scientist to feel a chimp’s ridged dick and conclude that there is significance.. .

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