Meta-analysis at the intersection of evolutionary ecology and conservation

We review the use and findings of meta-analyses that link evolution to conservation. An initial search of the literature produced 606 studies that appeared to be relevant, 120 of which proved to be narrow-sense meta-analyses. Only 23 explicitly intersected evolution and conservation. Collectively these meta-analyses summarized the results of some 2,000 studies of similar to 3,000 species. Most of the meta-analyses examined questions such as links between genetic variation and fitness of individuals in small populations, genetic consequences of habitat fragmentation, and changes in traits in time and space in response to a variety of human impacts ranging from pollution to invasive species and climate change. By summarizing the results of large numbers of disparate studies, meta-analyses usually confirmed theoretical expectations, but sometimes revealed that predicted relationships or differences are much weaker than conventionally assumed. They have also been helpful in pointing out benefits and pitfalls of alternative methodologies and metrics. Other major areas of conservation concern such as impacts of over-exploitation have been synthesized in other ways, but not yet by formal meta-analyses. We conclude that most of the meta-analyses that have been done so far are aimed more strongly toward advancing our understanding of evolution than of conservation. We remain hopeful that this tool will find increasing use in new questions at the intersection of these fields, and be aimed more directly at providing diagnoses and prescriptions for action in the field of conservation management.