Journal ArticleDOI
Sexual Selection and Sexual Dimorphism in Some Herbivorous Lizards
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TLDR
An analysis ofDimorphism patterns within the subfamily Iguaninae suggests that dimorphism is a highly variable condition that is not constrained in its distribution by historical factors.Abstract:
I tested the hypothesis that sexual selection affects body and especially head size in lizards by exploring patterns of sexual dimorphism and social organization among nine species of herbivorous lizard. Because these species do not partition food with respect to body and head size (as do insectivorous species), elimination of this factor allows a test of the effects of sexual selection on male lizards (these morphological features are important in fighting ability). As predicted by the sexual selection hypothesis, the three low male aggression species have little or no head size dimorphism, while the eight polygynous species show significant dimorphism of their head and body size. In the latter species male head size increases allometrically with body size, while decreasing head size in females is the general case. An analysis of dimorphism patterns within the subfamily Iguaninae suggests that dimorphism is a highly variable condition that is not constrained in its distribution by historical factors. Sex...read more
Citations
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Journal ArticleDOI
Ecological Causes for the Evolution of Sexual Dimorphism: A Review of the Evidence
TL;DR: If ecological causation for dimorphism can be demonstrated in so many cases, despite the inadequacies of the available criteria, the degree of sexual sizeDimorphism in many other animal species may well also have been influenced by ecological factors, and it may be premature of dismiss this hypothesis.
Journal ArticleDOI
Sexual dimorphism of head size in Gallotia galloti: testing the niche divergence hypothesis by functional analyses
TL;DR: The crushing phase of biting was modelled and the results show different strategies in allocation of muscle tissue between both sexes, which clearly illustrates that animals of both sexes can bite much harder than required for most insect food items, which does not support the niche divergence hypothesis.
Journal ArticleDOI
Phylogenies and the analysis of evolutionary sequences, with examples from seed plants.
TL;DR: A cladistic test of the hypothesis that the evolution of dioecy is favored in animal‐dispersed plants indicates that dioECy may have originated somewhat more often in such lineages, which must largely account for the observed species‐level correlation between dispersal and breeding system.
Journal ArticleDOI
A comparative test of adaptive hypotheses for sexual size dimorphism in lizards
TL;DR: The comparative data at present provide only weak support for these hypotheses as general explanations for SSD in lizards, and are consistent with the criticism that categorical variables may obscure much of the actual variation in intrasexual selection intensity needed to explain patterns in SSD.
Journal ArticleDOI
Mate choice, fecundity and sexual dimorphism in two pipefish species (Syngnathidae)
TL;DR: It is argued that sexual sizeDimorphism did not evolve by selection minimizing overlap in food niches between the sexes, because food production is high in the Zostera beds where the fishes live, and no size dimorphism was found in the sympatrically occurring S. typhle.
References
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Book
The Descent of Man, and Selection in Relation to Sex
TL;DR: In this paper, secondary sexual characters of fishes, amphibians and reptiles are presented. But the authors focus on the secondary sexual characteristics of fishes and amphibians rather than the primary sexual characters.
Journal ArticleDOI
The Descent of Man, and Selection in relation to Sex
TL;DR: The Descent of Man, and Selection in relation to Sex as mentioned in this paper, by Charles Darwin, &c. In two volumes. Pp. 428, 475, as mentioned in this paper.
Book
Ontogeny and Phylogeny
TL;DR: In this article, the authors propose a clock model of Heterochrony, which is a mechanism for separating the three stages of the development of an organism: birth, growth, and death.
Journal ArticleDOI
Sexual dimorphism, sexual selection, and adaptation in polygenic characters.
TL;DR: Sexual dimorphism may result from natural and/or sexual selection, and systems of mating are often thought to evolve in response to ecological pressures, although mating preferences may be self-reinforcing.