DIFFERENTIAL FLIGHT ACTIVITY AMONG KARYOTYPES - DAILY AND WEATHER-INDUCED CHANGES IN CHROMOSOMAL INVERSION POLYMORPHISM IN NATURAL-POPULATIONS OF DROSOPHILA-SUBOBSCURA

The question is posed whether karyotype frequencies in the active fraction of Drosophila subobscura populations vary consistently in the course of a day, or in accordance with weather changes. Significant daily variation occurred in all chromosomes with the exception of the sex chromosome. The proportions of the karyotypes U(st/1+2) and I(st/st) decreased from early to late morning and increased during the evening. I(st/1) displayed a complementary behaviour. The homokaryotypes O(st/st) and E(st/st) decreased both during the morning and the evening. Weather disturbances caused a remarkable variation in the frequencies of the standard gene arrangements.