Interpreting negative results with taxonomic and conservation implications: Another look at the distinctness of coastal California Gnatcatchers

摘要

A recent study by Zink et al. (2013) raises questions about how to interpret negative results in studies when the distinctness of a species of conservation concern is in question. Zink et al. found no evidence for genetic or ecological distinctness of the coastal California Gnatcatcher (Polioptila californica californica). We discuss why the genetic markers they chose were not well suited to the question of distinctness and how they overinterpreted negative results in their genetic and ecological analyses. We reanalyze their genetic data and find evidence that several genetic loci show significant differentiation in the coastal California Gnatcatchers. We provide recommendations for best practices in determining distinctness in phenotype, genetics, and ecology for California Gnatcatchers and other populations of conservation concern.