Spatial scale and temporal component of selection in side-blotched lizards
Author
Summary, in English
Spatial variation in selection has long been recognized as promoting population divergence and in maintaining genetic polymorphisms, but selection at a fine spatial scale is seldom measured directly. We analyzed spatial and temporal variation in selective regimes on egg size using long-term population data of the side-blotched lizard ( Uta stansburiana). Juvenile survival rates varied between years at a small spatial scale that was reflected as a strong interaction between the local neighborhood level and year. Spatially and temporally variable selection acted jointly on egg mass, which presumably would facilitate the maintenance of high additive genetic variance for this trait. Local selection gradients calculated at the neighborhood level were significantly correlated with the annual global selection gradients calculated at the metapopulation level. However, there was substantial variance in these local selective regimes, which suggests that strong local selection could go undetected if the analysis was limited to the global level. We also investigated the degree of spatial synchronization among outcrop in local selection gradients. The degree of synchrony was higher among later-clutch hatchlings than among first-clutch hatchlings, and we suggest that more intense density- and frequency-dependent selection on egg size later in the season is responsible for this effect.
Publishing year
2004
Language
English
Pages
726-734
Publication/Series
American Naturalist
Volume
163
Issue
5
Full text
- Available as PDF - 117 kB
- Download statistics
Links
Document type
Journal article
Publisher
University of Chicago Press
Topic
- Biological Sciences
Keywords
- competition
- egg mass
- frequency dependence
- polymorphism
Status
Published
Research group
- Evolution and Ecology of Phenotypes in Nature
ISBN/ISSN/Other
- ISSN: 0003-0147