High mutation frequency induced by hybridization

Abstract

The increase in variability that is a familiar result of the rearing of second generations from crosses between different races is certainly due chiefly to segregation and recombination of genes in which the parental races differed. There is, however, a persistent feeling that perhaps interracial crossing also induces the production of new mutations. The first attempt to test this view experimentally with Drosophila led to negative results (Duncan 1915). Belgovsky (1937) reported an increased frequency of somatic mutations in the hybrids between D. melanogaster and D. simulans, in x-ray experiments. The differences reported were not very striking, and in any case have little bearing on questions concerning spontaneous frequencies.