Density cycles and an offspring quantity and quality game driven by natural selection
Author
Summary, in English
A long-standing hypothesis posits that natural selection can favour two female strategies when density cycles. At low density, females producing many smaller progeny are favoured when the intrinsic rate of increase, r, governs population growth. At peak density, females producing fewer, high-quality, progeny are favoured when the carrying capacity, K, is exceeded and the population crashes. Here we report on the first example of a genetic r versus K selection game that promotes stable population cycles in lizards. Decade-long fitness studies and game theory demonstrated that two throat-colour morphs were refined by selection in which the strength of natural selection varied with density. Orange-throated females, r strategists, produced many eggs and were favoured at low density. Conversely, yellow-throated females, K strategists, produced large eggs and were favoured at high density. Progeny size should also be under negative frequency-dependent selection in that large progeny will have a survival advantage when rare, but the advantage disappears when they become common. We confirmed this prediction by seeding field plots with rare and common giant hatchlings. Thus, intrinsic causes of frequency- and density-dependent selection promotes an evolutionary game with two-generation oscillations.
Publishing year
2000
Language
English
Pages
985-988
Publication/Series
Nature
Volume
406
Issue
6799
Document type
Journal article
Publisher
Nature Publishing Group
Topic
- Biological Sciences
Status
Published
Research group
- Evolution and Ecology of Phenotypes in Nature
ISBN/ISSN/Other
- ISSN: 0028-0836