Why Nice Guys Usually Get The Girls

http://www.sciencedaily.com/releases/2009/11/091105143817.htm

ScienceDaily (Nov. 11, 2009) — Female water striders often reject their most persistent and aggressive suitors and prefer the males who aren't so grabby, according to new research. Water striders are insects commonly seen skittering across the surface of streams.

Groups of low-key male water striders mated with more females than did groups of highly sexually aggressive males, according to a study led by Omar Tonsi Eldakar of the University of Arizona's Arizona Research Laboratories.

The research contradicts previous laboratory studies that found the most sexually aggressive males are the most successful at reproducing, said Eldakar, who conducted the experiments while an instructor at Binghamton University in N.Y. He is now a postdoctoral research associate in UA's Center for Insect Science.

"Nice guys don't always finish last," he said. "In this study we've shown that it's possible for non-aggressive males to have the advantage."

His co-author John W. Pepper said, "If the early laboratory studies were a realistic representation of nature, nature should be overrun by hyperaggressive males -- and it's not. So something was wrong with that idea, and now we know what."

In the previous studies, the females were not able to leave areas populated by sexually aggressive males.

By simulating a more natural situation, the current study showed that female water striders moved away from areas where they were being harassed by males. The females preferred to hang out in locations where the males did not pursue females relentlessly.

The new research explains why hyperaggressive males are a minority in the water strider world, said Pepper, a UA assistant professor of ecology and evolutionary biology. The groups of water striders that were composed of females and less aggressive males had more overall mating success.

The finding supports the idea that natural selection simultaneously acts on individuals and on groups of individuals, he said.

"Omar's work says that what happens between groups is important," Pepper said. "Individually, less aggressive males may get a smaller piece of the pie. But a group of less aggressive males has a bigger pie, because the males don't drive away females or harass them so much they don't reproduce."

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