Sexual size differences in the genus Sceloporus

Fitch, Henry S.

doi:10.5962/bhl.part.17244

Cited by 80 publications

(96 citation statements)

References 16 publications

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“…An additional dimension was later incorporated to the fecundity selection hypothesis by Tinkle et al (1970) and Fitch (1978Fitch ( , 1981. These authors suggested that the intensity of fecundity selection on female body size would increase as a function of reduced opportunities for reproductive frequency caused by environmental constraints.…”

Section: Introductionmentioning

confidence: 99%

Fecundity Selection and the Evolution of Reproductive Output and Sex-Specific Body Size in the Liolaemus Lizard Adaptive Radiation

2011

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Fecundity is a primary component of fitness. Theory predicts that the evolution of fecundity through increased brood size results from fecundity selection favouring larger female size to accommodate more offspring and to store more energy. This is expected to generate asymmetric selection on body size between the sexes, ultimately driving evolution of female-biased sexual size dimorphism. Additionally, it has been predicted that the intensity of fecundity selection increases when the opportunities for reproduction are reduced by the limiting thermal effects of increasing latitude-elevation (i.e. decreasing environmental temperatures) on the length of the reproductive season. This later factor would be particularly strong among ectotherms, where reproduction is heavily temperature-dependent. However, this integrative perspective on reproductive evolution by fecundity selection has rarely been investigated. Here, we employ a comparative approach to investigate these predictions in Liolaemus, a prominent lizard radiation. As expected, Liolaemus reproductive output (i.e. offspring number per reproductive episode) increases predictably with increasing female size. However, contrary to predictions, we found that increased fecundity does not translate into female-biased SSD, and that combined latitude-elevation does not impose a detectable effect on fecundity. Finally, our allometric analyses reveal that SSD scales with body size, which supports the occurrence of Rensch's rule in these lizards. We discuss the evolutionary implications of our results, and the assumptions of the investigated hypotheses.

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Section: Introductionmentioning

confidence: 99%

Fecundity Selection and the Evolution of Reproductive Output and Sex-Specific Body Size in the Liolaemus Lizard Adaptive Radiation

2011

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“…Some studies on lizards have shown that morphological differences between males and females might result in differences in diet composition (FITCH 1978, SCHOENER et al 1982, PREEST 1994. However, sexual dimorphism in size does not necessarily imply feeding differences between the sexes.…”

Section: Discussionmentioning

confidence: 99%

Feeding ecology of the pygmy gecko Coleodactylus natalensis (Squamata: Sphaerodactylidae) in the Brazilian Atlantic Forest

Lisboa¹,

Sales²,

Freire³

2012

Zoologia (Curitiba)

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We studied the feeding ecology of a population of Coleodactylus natalensis Freire, 1999, an endemic gecko of Atlantic Forest fragments in the state of Rio Grande do Norte, northeastern Brazil. Lizards (N = 49) were collected manually through active search in the four habitats of Parque Estadual Dunas de Natal, type locality of the species. In the laboratory, we measured the lizards and registered the number of consumed prey items identified to Order, its dimensions and frequencies. We also collected samples of leaf litter in each habitat to determine prey availability. Females were significantly larger than males, but head size did not differ between the sexes. The most important prey categories in the diet of C. natalensis based on number, volume and frequency were Isopoda and Araneae. Prey categories with highest importance indices in the diet were Isopoda, Araneae, Homoptera and Gryllidae. The diets of adult males and females were similar with respect to prey size, but differed qualitatively, mainly due to the larger trophic spectrum of females. We found some variations on trophic niche breadths and food preferences of lizards between habitats, but in general niche breadths were intermediate, and the most elected prey categories were Isopoda, Araneae, Homoptera and Thysanoptera. High electivities for Isoptera and Gryllidae occurred only in the open habitats (restinga and dunes), and for Mantodea in the forested habitats (high and low forest). Collembola was consumed in the same proportion of the environment, and Acarina and Formicidae had negative values of electivity, indicating rejection. We conclude that the population studied seems to have a selective diet, preferring relatively large prey items that are less abundant in the leaf litter, and possibly avoiding potentially toxic prey

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“…All data on signal complexity were compiled directly from published studies [25,[62][63][64][65][66][67] except for frogs (see below). Indices of sociality were obtained from the same sources used for communication data (frogs [68]; lizards, distantly related [25]; birds [66]), unpublished data from the authors of these studies (ants-E. van Wilgenburg, M. R. E. Symonds & M. A. Elgar 2011, unpublished data) or compiled separately from other literature (lizards, closely related [69]). …”

Section: Methodsmentioning

confidence: 99%

Is sociality required for the evolution of communicative complexity? Evidence weighed against alternative hypotheses in diverse taxonomic groups

Ord

Garcia‐Porta

2012

Phil. Trans. R. Soc. B

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Complex social communication is expected to evolve whenever animals engage in many and varied social interactions; that is, sociality should promote communicative complexity. Yet, informal comparisons among phylogenetically independent taxonomic groups seem to cast doubt on the putative role of social factors in the evolution of complex communication. Here, we provide a formal test of the sociality hypothesis alongside alternative explanations for the evolution of communicative complexity. We compiled data documenting variations in signal complexity among closely related species for several case study groups-ants, frogs, lizards and birds-and used new phylogenetic methods to investigate the factors underlying communication evolution. Social factors were only implicated in the evolution of complex visual signals in lizards. Ecology, and to some degree allometry, were most likely explanations for complexity in the vocal signals of frogs (ecology) and birds (ecology and allometry). There was some evidence for adaptive evolution in the pheromone complexity of ants, although no compelling selection pressure was identified. For most taxa, phylogenetic null models were consistently ranked above adaptive models and, for some taxa, signal complexity seems to have accumulated in species via incremental or random changes over long periods of evolutionary time. Becoming social presumably leads to the origin of social communication in animals, but its subsequent influence on the trajectory of signal evolution has been neither clear-cut nor general among taxonomic groups.

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Sexual size differences in the genus Sceloporus

Cited by 80 publications

References 16 publications

Fecundity Selection and the Evolution of Reproductive Output and Sex-Specific Body Size in the Liolaemus Lizard Adaptive Radiation

Fecundity Selection and the Evolution of Reproductive Output and Sex-Specific Body Size in the Liolaemus Lizard Adaptive Radiation

Feeding ecology of the pygmy gecko Coleodactylus natalensis (Squamata: Sphaerodactylidae) in the Brazilian Atlantic Forest

Is sociality required for the evolution of communicative complexity? Evidence weighed against alternative hypotheses in diverse taxonomic groups

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