() is a male germline specific gene in that can trigger the male germline sexual fate and regulate spermatogenesis, and its human homologue can rescue fecundity defects in male flies lacking this gene. These findings prompted us to investigate conservation of reproductive strategies through studying the evolutionary origin of this gene. We find that is present only in select species including mammals and some insects, whereas the closely related () is in the genome of most metazoans. Interestingly, phylogenetic analyses showed that vertebrate and insect genes did not evolve from a common ancestor but rather through independent duplication events from an ancestral This is an example of parallel evolution in which a male germline factor evolved at least twice from a pre-existing template to develop new regulatory mechanisms of spermatogenesis.