Non-Random Associations of Inversions

Abstract

If we may generalize from the best studied genera, chromosomal inversions have played a significant role in the evolution of Dipteran species and their adaptation to the environment. A prime factor in the development and action of inversions has been their effect on recombination— within the inversion limits, adjacent to them, even on heterologous chromosomes. Recently I have been working with inversions that are related to recombination in yet another way, namely, complexes of linked inversions which occur or are maintained in non-random associations. In this paper I would like to document the several types of non-random associations in the species which I have studied, Drosophila robusta, consider how widespread the phenomenon might be in other species, and briefly discuss the mechanism for maintaining the associations.