Quote of the Month
"Even apparently similar adaptations may be built from genetically different components."
-Theodosius Dobzhansky
Introduction
Standing patterns of genetic diversity result from the interplay of several population genetic processes, such as natural selection, genetic drift and migration. Methods can be developed to identify which fraction of this signal can be attributed to these processes. When used in a hypothesis testing framework, however, all existing methods do not exhaustively divide the sample space into mutually incompatible outcomes; so that rejection of one hypothesis, a null hypothesis for example, does not necessarily imply that the alternative is true nor even likely. The reason is that several different processes can individually, as well as jointly, result in the same patterns. It is prudent, therefore, to utilize a range of methods that each examines different aspects of the standing patterns of genetic diversity. Recently we have begun collaborating with Rodney Dyer and his lab to examine the use of his measure of conditional genetic covariance, in combination with high-throughput SNP genotyping data, to infer patterns of natural selection across genomes.