1932

Abstract

Abstract

Small populations are predicted to have reduced capacity to adapt to environmental change for two reasons. First, population genetic models indicate that genetic variation and potential response to selection should be positively correlated with population size. The empirical support for this prediction is mixed: DNA markers usually reveal low heterozygosity in small populations, whereas quantitative traits show reduced heritability only in the smallest and most inbred populations. Quantitative variation can even increase in bottlenecked populations although this effect seems unlikely to increase the adaptive potential of populations. Second, individuals in small populations have lower fitness owing to environmental stress and genetic problems such as inbreeding, which can substantially increase the extinction probability of populations in changing environments. This second reason has not been included in assessments of critical population size assuring evolvability and makes it likely that many small threatened populations have a decreased potential for adaptation.

Loading

Article metrics loading...

/content/journals/10.1146/annurev.ecolsys.37.091305.110145
2006-12-01
2024-12-13
Loading full text...

Full text loading...

/content/journals/10.1146/annurev.ecolsys.37.091305.110145
Loading
/content/journals/10.1146/annurev.ecolsys.37.091305.110145
Loading

Data & Media loading...

  • Article Type: Review Article
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error