Sexual selection,sexual dimorphism and plant phylogeny

Summary Darwin examined sexual dimorphism in animals, arguing that sexual selection was important in the evolution of such dimorphism. Sexual dimorphism in plants may have parallel causes and costs.The processes that contribute to sexual dimorphism may also lead to speciation and morphological differences among related species, as argued originally by Darwin. Where sexes are separate and dimorphism is well-developed, males of related animal species (both vertebrate and invertebrate) are often strikingly different from each other, while females may be virtually indistinguishable. A similar pattern may exist in plants: it is frequently the males (of dioecious taxa) or the male portions of the flower (in co-sexual flowers) that apparently have diversified. I suggest that the similarity of pattern may be accounted for by a similarity of process.In addition, sexual selection may have contributed to certain evolutionary trends within the angiosperms and, indeed, to angiosperm radiation.