Detecting Signatures of Selection from DNA Sequences Using Datamonkey

Natural selection is a fundamental process affecting all evolving populations. In the simplest case, positive selection increases the frequency of alleles that confer a fitness advantage relative to the rest of the population, or increases its genetic diversity, and negative selection removes those alleles that are deleterious. Codon-based models of molecular evolution are able to infer signatures of selection from alignments of homologous sequences by estimating the relative rates of synonymous (dS ) and non-synonymous substitutions (dN ). Datamonkey (http://www.datamonkey.org ) provides a user-friendly web interface to a wide collection of state-of-the-art statistical techniques for estimating dS and dN and identifying codons and lineages under selection, even in the presence of recombinant sequences.