Evolutionary rescue in a changing world.

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Evolutionary rescue in a changing world.

Trends Ecol Evol. 2014 Sep;29(9):521-30

Authors: Carlson SM, Cunningham CJ, Westley PA

Abstract
Evolutionary rescue occurs when adaptive evolutionary change restores positive growth to declining populations and prevents extinction. Here we outline the diagnostic features of evolutionary rescue and distinguish this phenomenon from demographic and genetic rescue. We then synthesize the rapidly accumulating theoretical and experimental studies of evolutionary rescue, highlighting the demographic, genetic, and extrinsic factors that affect the probability of rescue. By doing so, we clarify the factors to target through management and conservation. Additionally, we identify several putative cases of evolutionary rescue in nature, but conclude that compelling evidence remains elusive. We conclude with a horizon scan of where the field might develop, highlighting areas of potential application, and suggest areas where experimental evaluation will help to evaluate theoretical predictions.

PMID: 25038023 [PubMed – indexed for MEDLINE]

via pubmed: school of aquatic an… http://ift.tt/1li6na6

Evolutionary rescue in a changing world.

Written by

Evolutionary rescue in a changing world.

Trends Ecol Evol. 2014 Jul 15;

Authors: Carlson SM, Cunningham CJ, Westley PA

Abstract
Evolutionary rescue occurs when adaptive evolutionary change restores positive growth to declining populations and prevents extinction. Here we outline the diagnostic features of evolutionary rescue and distinguish this phenomenon from demographic and genetic rescue. We then synthesize the rapidly accumulating theoretical and experimental studies of evolutionary rescue, highlighting the demographic, genetic, and extrinsic factors that affect the probability of rescue. By doing so, we clarify the factors to target through management and conservation. Additionally, we identify several putative cases of evolutionary rescue in nature, but conclude that compelling evidence remains elusive. We conclude with a horizon scan of where the field might develop, highlighting areas of potential application, and suggest areas where experimental evaluation will help to evaluate theoretical predictions.

PMID: 25038023 [PubMed – as supplied by publisher]

via pubmed: school of aquatic an… http://ift.tt/1li6na6

Predation by bears drives senescence in natural populations of salmon.

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Predation by bears drives senescence in natural populations of salmon.

PLoS One. 2007;2(12):e1286

Authors: Carlson SM, Hilborn R, Hendry AP, Quinn TP

Abstract
Classic evolutionary theory predicts that populations experiencing higher rates of environmentally caused (“extrinsic”) mortality should senesce more rapidly, but this theory usually neglects plausible relationships between an individual’s senescent condition and its susceptibility to extrinsic mortality. We tested for the evolutionary importance of this condition dependence by comparing senescence rates among natural populations of sockeye salmon (Oncorhynchus nerka) subject to varying degrees of predation by brown bears (Ursus arctos). We related senescence rates in six populations to (1) the overall rate of extrinsic mortality, and (2) the degree of condition dependence in this mortality. Senescence rates were determined by modeling the mortality of individually-tagged breeding salmon at each site. The overall rate of extrinsic mortality was estimated as the long-term average of the annual percentage of salmon killed by bears. The degree of condition dependence was estimated as the extent to which bears killed salmon that exhibited varying degrees of senescence. We found that the degree of condition dependence in extrinsic mortality was very important in driving senescence: populations where bears selectively killed fish showing advanced senescence were those that senesced least rapidly. The overall rate of extrinsic mortality also contributed to among-population variation in senescence-but to a lesser extent. Condition-dependent susceptibility to extrinsic mortality should be incorporated more often into theoretical models and should be explicitly tested in natural populations.

PMID: 22423309 [PubMed – indexed for MEDLINE]

via pubmed: school of aquatic an… http://www.ncbi.nlm.nih.gov/pubmed/22423309?dopt=Abstract