GENETIC BASIS OF SOUND PRODUCTION IN DROSOPHILA-PSEUDOOBSCURA AND DROSOPHILA-PERSIMILIS

1. 1. Males of the sibling species Drosophila pseudoobscura and D. persimilis perform courtship songs which differ both quantitatively and qualitatively. Pseudoobscura produces two songs, a low repetition rate song which consists of trains of 525 Hz pulses at 6 per sec and a high repetition rate one in which 250 Hz pulses are repeated at 24 times per sec. In persimilis the low repetition rate song is absent or occurs in a very abbreviated form and the high repetition rate song consists of 525 Hz pulses repeated at 15 times per sec. 2. 2. The inheritance of these songs was investigated by examining the songs produced by the F1 and backcross progeny of crosses between the species. 3. 3. The presence of the low repetition rate song and the frequency within pulse of the high repetition rate songs are controlled by genes located on the X chromosome. The pulse repetition rate of the high repetition rate song is inherited independently from the former characters. 4. 4. Possible evolutionary implications of the mode of inheritance of the songs are discussed. © 1969.