Friday genitalia FTW

Patricia Brennan is an evolutionary morphologist who teaches at Mt. Holyoke College (her website is here), and her speciality is animal genitalia. As the locus of morphological contact during reproduction, one would expect both natural and sexual selection to act very strongly on genitalia, and indeed they have (see William Eberhard’s underappreciated book Sexual Selection and Animal Genitalia). I suppose that because of a stigma attached to genitals, they aren’t studied nearly as much as they should be by evolutionary biologists. Here’s a video of Brennan and some of her work, first published at the xxfiles in Science.

Although biologists have concentrated on male genitalia, as those are often the most easily seen diagnostic features of related insects (that itself speaks to the importance of sexual selection, for why should genitals change so quickly compared to other traits?), Brennan also looks at the vaginas, which, being internal, are harder to see. She uses silicon molds to define their shape.

The male mako shark genitals described at 1:40 are way cool, and the spines on them probably show some kind of antagonism between male and female during copulation: the male wants to hold on to inject his sperm, but the spines don’t allow a female to reject such a male, and may damage her as well. You want more? Read about “traumatic insemination,” evolution’s version of Fifty Shades of Grey.

Brennan specializes in duck genitals, which can often be amazingly long and contorted (see one of her short videos at the Science page).




  1. Ken Kukec
    Posted January 27, 2017 at 3:27 pm | Permalink

    Reminds me to pick up a box a chocolates and a dozen roses on the way home tonight, maybe a bottle of bubbly, too, put some Sinatra on the stereo when I walk in the door, go all old-school.

    Call me easily suggestible.

    • Dominic
      Posted January 30, 2017 at 10:50 am | Permalink

      Open a box of quackers…

  2. JonLynnHarvey
    Posted January 27, 2017 at 3:39 pm | Permalink

    I am not at all an expert on biology, but I am fairly expert on the history of human language.

    As a supplement, I offer this Slate article detailing all the various slang expressions in use around the world about human-animal copulation.

    Oh, and I’m sorry to see Fox News accuse her of ‘fowl play’. (Bah-Dum!)

  3. merilee
    Posted January 27, 2017 at 4:12 pm | Permalink

    I don’t get the whole FTW shtick??

    • Christopher
      Posted January 27, 2017 at 6:31 pm | Permalink

      Free The Willy?

      • Merilee
        Posted January 27, 2017 at 6:49 pm | Permalink


  4. Christopher
    Posted January 27, 2017 at 6:39 pm | Permalink

    That was too interesting a post to have only garnered three comments.

    I am honestly shocked, not at the genitalia, but at the fact that junk of both sexes has been so little studied. I assumed, thanks to ahem, exposure (cough cough) to entomology and it’s obsession with wangs and the like (for species ID, not because entomologists are more perverse than any other group of biologists) that there would have been an equal amount of vertebrate studies. Now, if you want to put a little excitement into your friday night, google “terrifying sex organs of male turtles” for the Tetrapod Zoology bl*g post about that topic. Well worth your time, I promise. As anyone who has cared for a male chelonian can attest, they are spectacular in the extreme.

    Posted January 27, 2017 at 6:54 pm | Permalink

    My dorm at Michigan State Univ. was adjacent to the river and my room was at a corner where two wings of the building joined so I was given a front row seat to duck copulation. The drakes would herd the females into the corner where, accompanied by much squawking, the gang rape would happen

  6. J. Quinton
    Posted January 27, 2017 at 7:24 pm | Permalink

    Ducks are the rapists *uber alles* of the natural world.

    A friend of mine had a farm with chickens. She said a pack of ducks literally raped one of her chickens to death.

  7. Michael Scullin
    Posted January 27, 2017 at 7:29 pm | Permalink

    What could be more unreliable than a Fox News online poll? I think I could have predicted that probably at least 90% would think not just studying animal genitalia is dumb but very probably that most science is dumb. Just read the titles of much scientific literature. And make that 88.7% because that makes it sound like a real poll right down to the tenth of a percent. Some of the elders here remember Wisconsin senator William Proxmire and his conferences where he would read the titles of various grants which generally sounded pretty dumb to people who were and are science-free. Does any group of people come to mind? Large group of people? Our president, however, is one who is not the least reluctant to tell us all about his activity with genitalia.

  8. rickflick
    Posted January 27, 2017 at 7:52 pm | Permalink

    Well, it’s about time!

  9. Alpha Neil
    Posted January 27, 2017 at 8:32 pm | Permalink

    Louis C.K. talking about his junk

  10. Jonathan Wallace
    Posted January 28, 2017 at 2:49 am | Permalink

    As well as getting the sperm to the right place to fertilize the eggs, the morphology of penises is often also concerned with preventing the sperm of rival males fertilizing those same eggs. For example in some cases the penis is structured in a way that enables semen from prior matings to be scooped out.

  11. Mark Sturtevant
    Posted January 28, 2017 at 7:41 am | Permalink

    A very welcome topic to peruse this Saturday morning, over coffee. This is very interesting research.
    The scenes of her doing parafilm tissue sections really took me back to a great histology class where we did the same thing. This is a technique that requires much attention to tiny detail. I loved slowly learning the craft.

  12. Ken Elliott
    Posted January 28, 2017 at 12:06 pm | Permalink

    Utterly fascinating. Thank you for posting this. I will always learn quite a bit from these types of posts because I never pursued any type of scientific education beyond high school. That is my loss. I wish my curiosity had been as keen then as it has become recently.

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