Fig. 2. Species distribution of P elements (modified from Engels 1992) : Southern blotting was used to determine the presence or absence of P element sequences in various Drosophila species to illustrate the evidence for recent invasion (Daniels et al. 1990 and references cited therein) . Estimates of divergence time, given in millions of years ago, are averages derived from Lachaise et al. (1988) and Spicer (1988) .
Site admin: - Bill Engels, .... 16 March 1996