Social Parasites and the Molecular Basis of Phenotypic Diversity.

Contrasting phenotypes arise from similar genomes through a combination of losses, gains,co-aptionan and modifications of inherited genomic material. Understanding the molecularr basis of this phenotypic diversity is a fundamental challenge in modern evolutionary biology. Comparisons of the genes and their expression patterns underlying traits in closelyr elated species offfer a inunrivaled opportunity to evaluate the extentto which genomic material is reorganized to produce novel traits. Advances in molecular methods now allow us to dissect the molecular machinery underlying phenotypic diversity in almost any organism,from single-cell edentities to the most complex vertebrates.Here we discuss how comparisons of social parasites and their free-living hosts may provide unique insights into the molecular basis of phenotypic evolution.