Drosophila hybrids in nature: proof of gene exchange between sympatric species

Science  05 Sep 1975:
Vol. 189, Issue 4205, pp. 806-807
DOI: 10.1126/science.1162353


Genetic studies of two closely related endemic Hawaiian species show that in one area of sympatry about 2 percent of the naturally occurring individuals are hybrids. More than 20 times this many would be expected if the population consisted of a single panmictic unit. Despite hybridization, natural selection appears to maintain the essential integrity of each separate gene pool.