Topic: "Science Marches On"
R. Brian Langerhans, a graduate student at Washington University in St. Louis, published the first study ever done on predators as an influence on genital evolution in the Proceedings of the National Academy of Sciences. Langerhans studied two species of fish that give birth to live young, which he caught in ponds in the Bahamas and in Texas. The study showed that males taken from ponds that contained predatory fish had smaller sexual organs--by about 15 percent--than males from predator-free locations.
Females of the two species preferred the males with larger genitalia, according to the study. While males with large sex organs were more likely to get mates, they were also more likely to be eaten by predators because their genitalia are a drag on their swimming speed. "It's a groundbreaking study," said Duncan Irschick, an evolutionary biologist at Tulane University. "Sometimes male sex organs are the only thing that distinguishes one species from another," he said.
Langerhans concludes the study by pointing out that the subject males have non-retractable sex organs, and that they wave them at females in order to attract them. "It's not so dramatically obvious to our eyes," said Langerhans, "but for a female fish, a 15 percent difference is huge."
What? You think I'm making this all up? Let's have a little decorum out there while Frodo makes a point or two here.
First of all, I'll bet the fish with the little weenies came out of the ponds in Texas.
Secondly, Frodo is very curious about the male fish whose swimming speed is lessened due to the perspective of larger size. Evidently the manuverability of the fish is not lessened due to the presence of an extended rudder.
Finally, Frodo takes note of a personal lesson in this very valuable study. Frodo is going to have to be much more careful around predators.
Posted by loveysdaddyga at 9:18 PM EDT
Updated: Wednesday, May 11, 2005 9:25 PM EDT