Genetic variation of Drosophila melanogaster natural populations

Abstract Drosophila melanogaster natural populations show considerable show considerable genetic variation in different geographicc regions. The nature of this variations suggests that the evolutionary history of the species involved the spreading of ancestral Afrotropical populations through Eurasia and, more recently, to America and Australia. Variation is accounted for by area effects, founder events, genetic drift, reduced gene flow, climatic and other local adaptations, and a presumed recent invasion by mob'le genetic elements.