Adaptive landscapes and density-dependent selection in declining salmonid populations: going beyond numerical responses to human disturbance.

ABSTRACT: Theory suggests an important role for population density in shaping adaptive landscapes through density-dependent selection. Here, we identify five methodological approaches for studying such selection, review the existing empirical evidence for it, and ask whether current declines in abundance can be expected to trigger evolutionary responses in salmonid fishes. Across taxa we find substantial amounts of evidence for population density influencing the location of adaptive peaks for a range of traits, and, in the presence of frequency dependence, changing the shape of selection (stabilizing versus disruptive). For salmonids, biological and theoretical considerations suggest that the optimal value of a number of traits associated with juvenile competitive ability (e.g. egg size, timing of e

SUBMITTER: Einum S 

PROVIDER: S-EPMC3352434 | biostudies-literature | 2008 May

REPOSITORIES: biostudies-literature