Please insert your Sir Mix-a-Lot joke here

Humans' have exceptionally rounded rear ends compared to our primate relatives. Turns out, that beefed-up gluteus maximus helps stabilize our upper body when we run, keeping us from falling forward. Read more about the biology and theoretical evolution of running at the Harvard Gazette. (Via Nicholas Thompson)



  1. So that’s why we are, as I like to call us, the “big-butted apes.” I’ve always wondered.

  2. Ok people, this refers to ‘muscular’ hypertrophy, so lay off the crispy cremes.

  3. Where, exactly, are we inserting this joke? I have to tell you, nobody’s inserting anything near my gluteus maximus unless they’ve got a medical certificate, or bought me a drink first.

  4. We might have the biggest asses among primates, but mandrills still have us beat for sheer showiness.

  5. So have male humans evolved a counterbalance in the front?  We’re much larger than other primates.  Gorillas have an average erect penis length of 1.25″.

    1. Have you read Desmond Morris’ “The naked man”? It presents lots of interesting data about sexual characters, and adaptive hypotheses to attempt to explain them (including the shape of the human penis, for example)

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