Homeobox DNA polymorphisms (restriction fragment length polymorphisms, RFLPs) were first found in 13 individuals, and then in 121 subterranean mole rats of the Spalax ehrenbergi superspecies in Israel. Spalacidae are adapted morphologically to life underground apparently since Oligocene times, 30 million years ago. The superspecies S. ehrenbergi comprises four chromosomal species (2n = 52, 54, ...

ATURAL populations of Drosophila are generally composed of complex arrays of different gene arrangements, but show a remarkable uniformity regarding the outward appearance of the flies. Therefore, color polymorphism is rare and chromosome polymorphism is common in this genus. Only a few species are either polymorphic with respect to externally visible traits or monomorphic with respect to gene ...

The processes governing the evolution of sexual dimorphism provided a foundation for sexual selection theory. Two alternative processes, originally proposed by Darwin and Wallace, differ primarily in the timing of events creating the dimorphism. In the process advocated by Darwin, a novel ornament arises in a single sex, with no temporal separation in the origin and sex-limitation of the novel ...

Distyly is a floral polymorphism with reciprocal placement of male and female structures, heteromorphic self-incompatibility, other ancillary traits. However, breeding system breakdowns loss are common. Here we traced the diversification strategies in type genera tribes Palicoureeae Psychotrieae discussed evolution distyly phylogenetic framework. We used literature field information for systems...

Some species have potential for intense mate competition yet exhibit little or no sexual size dimorphism, despite predictions from sexual selection theory. Using a conceptual model, we show the conditions for which passive mate guarding with copulatory plugs can be an alternative and more successful strategy to active (direct) guarding, reducing selection pressure on large male size. The model ...