Sexual selection on chromosomal polymorphism in drosophila subobscura

Abstract

Experiments were conducted to analyse the pattern of mating and to look for sexual selection differences among karyotypes of Drosophila subobscura. This was done by assaying the mating structure of large experimental populations of this species set up with different frequencies of OST and O3+4+7 chromosomal arrangements. From the experimental results, it is concluded that the mating pattern is at random and that the mating success of the male homokaryotypes OST/OST and O3+4+7O3+4+7, relative to that of the heterokaryotype OST/O3+4+7, is frequency-dependent favouring the rare male. These results are discussed in connection with the stable equilibrium attained in experimental population cages containing the OST and O3+4+7 chromosomal arrangements. © 1986 The Genetical Society of Great Britain.