Details

Autor(en) / Beteiligte

• Takahashi, Yuma
• Yoshimura, Jin
• Morita, Satoru
• Watanabe, Mamoru

Titel

NEGATIVE FREQUENCY-DEPENDENT SELECTION IN FEMALE COLOR POLYMORPHISM OF A DAMSELFLY

Ist Teil von

• Evolution, 2010-12, Vol.64 (12), p.3620-3628

Ort / Verlag

Malden, USA: Blackwell Publishing Inc

Erscheinungsjahr

2010

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• Negative frequency-dependent selection (NFDS) is one of the most powerful selective forces maintaining genetic polymorphisms in nature. Recently many prospective cases of polymorphisms by NFDS have been reported. Some of them are very complicated, although strongly supportive of the NFDS. Here we investigate NFDS in wild populations of the dimorphic damselfly Ischnura senegalensis, in which females occur as andromorphs and gynomorphs. Specifically, we (1) test fitness responses to morph frequencies, (2) built a simple population genetic model, and (3) compare the observed and predicted morph-frequency dynamics. Fitnesses of the two morphs are an inverse function of its own frequency in a population, and are about equal when their frequencies are similar. Thus the conditions necessary for NFDS are satisfied. The long-term field surveys show that the morph frequencies oscillate with a period of two generations. Morph frequencies in a small population undergo large oscillations whereas those in a large population do small oscillations. The demographic properties of the observed dynamics agree well with those of our model. This example is one of the simplest confirmed cases of NFDS maintaining genetic polymorphisms in nature.