Today PLoS One published an article by behavioral ecologist Patricia Brennan* and her colleagues on the evolution of duck genitalia. Male ducks are unusual birds because they have long twisty phalluses. Surprisingly, no one had actually bothered to study female duck genitalia until Brennan began her studies. She explained her thinking to the New York Times:
Brennan noted that in species with forced mating the males had larger phalluses and the females had more complex oviducts. She hypothesizes that the oviducts evolved as a way of blocking the sperm from unwanted males, which, in turn, drove the evolution of longer, more flexible phalluses.
“So what does the female look like?” she said. “Obviously you can’t have something like that without some place to put it in. You need a garage to park the car.”
The lower oviduct (the equivalent of the vagina in birds) is typically a simple tube. But when Dr. Brennan dissected some female ducks, she discovered they had a radically different anatomy. “There were all these weird structures, these pockets and spirals,” she said.
Somehow, generations of biologists had never noticed this anatomy before. Pondering it, Dr. Brennan came to doubt the conventional explanation for how duck phalluses evolved.
Dr. McCracken, who discovered the longest known bird phallus on an Argentine duck in 2001, is struck by the fact that it was a woman who discovered the complexity of female birds. “Maybe it’s the male bias we all have,” he said. “It’s just been out there, waiting to be discovered.”What else have male scientists missed?
* Brennan is a postdoctoral fellow with Professor Tim Birkhead in the Department of Animal and Plant Sciences at the University of Sheffield, and is also with Professor Richard Prum in the Department of Ecology and Evolutionary Biology at Yale.
Article: Carl Zimmer, "In Ducks, War of the Sexes Plays Out in the Evolution of Genitalia," New York Times, April 30, 2007
Full Citation: Brennan PL, Prum RO, McCracken KG, Sorenson MD, Wilson RE, et al. (2007) Coevolution of Male and Female Genital Morphology in Waterfowl. PLoS ONE 2(5): e418. doi:10.1371/journal.pone.0000418
Tags: duck genitalia, Patricia Brennan, women in science (via Pharyngula)