Picky Females Promote Diversity

ScienceDaily (Apr. 1, 2012) — Picky females play a critical role in the survival and diversity of species, according to a Nature study by researchers from the University of British Columbia and the International Institute for Applied Systems Analysis (IIASA) in Austria.

The new Nature study on "picky females" may explain how cichlids, a fish found in Lake Victoria in Africa, can coexist in high diversity in the same habitat. (Credit: Ole Seehausen, Fish Ecology and Evolution, Eawag, Switzerland)

To date, biodiversity theories have focused on the role played by adaptations to the environment: the species best equipped to cope with a habitat would win out, while others would gradually go extinct. The new study presents the first theoretical model demonstrating that selective mating alone can promote the long-term coexistence of species — such as frogs, crickets, grasshoppers and fish — that share the same ecological adaptations and readily interbreed.

“The focus on ecological adaptation has failed to explain much of the biodiversity we see right before our eyes,” says the study’s first author Leithen M’Gonigle, a postdoctoral fellow at the University of California at Berkeley, who developed this work while a PhD candidate at UBC.

“Our model shows that species can stably coexist in the same habitat as long as two simple conditions are met. First, the distribution of resources they use must not be uniform, so that groups of females with different mate preferences can occupy different resource hotspots. Second, females must pay a cost for being choosy, through reduced survival or fecundity,” says M’Gonigle.