The theory of sexual selection and isolation lays heavy emphasis on the role of the female - defined as the sex with the higher parental investment - in these activities. The male investment is, however, not negligible and we hypothesize that, under certain, well defined
conditions, sexual isolation will be a function of male behaviour, whereas sexual selection will always mainly be a female
... [Show full abstract] prerogative.
We present behavioural data from observations of intra- and interspecific single pair
matings of 5 sibling species of the Drosophila melanogaster group - D. melanogaster, D. simulans, D. mauritiana, D. teissieri, D. yakuba.
The results are consistent with our hypothesis. Males are primarily responsible for sexual
isolation, whereas females dominate sexual selection.