THE FITNESS OF SINGLE-SPECIES POPULATIONS OF DROSOPHILA.

Abstract

A population bottle technique for the maintenance of continuous populations of Drosophila (Barker, 1960) has been used in studies of interspecific competition and population fitness (Barker, 1963 a, b). In these studies, the wild type Oregon-R-C stock of D. melanogaster and the vermilion eye-color mutant of D. simulans have been used extensively, and when in competition, the latter is rapidly eliminated. In a current series of experiments, the nature of this interspecific competition is being studied, but the dynamics of single-species populations provide useful comparative information. With the description of the technique (Barker, 1960), some results for average population numbers of D. melanogaster and D. simulans over 11 generations were presented. These same populations have been maintained for 222 weeks (111 generations, Barker, 1962, 1967) and provide the data in this paper.