Size-Dependent Selective Mechanisms on Males and Females and the Evolution of Sexual Size Dimorphism in Frogs

Author(s)

Nali, Renato C. ^[1] ; Zamudio, Kelly R. ^[2] ; Haddad, Celio F. B. ^[3] ; Prado, Cynthia P. A. ^[4]

Affiliation

^[1] Univ Estadual Paulista, Inst Biociencias, Dept Zool, Programa Grad Ciencias Biol Zool, BR-13506900 Rio Claro, SP - Brazil

^[2] Cornell Univ, Dept Ecol & Evolutionary Biol, Ithaca, NY - USA

^[3] Univ Estadual Paulista, Inst Biociencias, Dept Zool, BR-13506900 Rio Claro, SP - Brazil

^[4] Univ Estadual Paulista, Fac Ciencias Agrarias & Vet, Dept Morfol & Fisiol Anim, BR-14884900 Jaboticabal, SP - Brazil

• Document type: Journal article
• Source: American Naturalist; v. 184, n. 6, p. 727-740, DEC 2014.
• Web of Science Citations: 24

Abstract

Sexual size dimorphism (SSD) varies in animals from male biased to female biased. The evolution of SSD is potentially influenced by a number of factors, such as territoriality, fecundity, and temporal breeding patterns (explosive vs. prolonged). In general, frogs show female-biased SSD with broad variance among species. Using comparative methods, we examine how different selective forces affect male and female sizes, and we test hypotheses about size-dependent mechanisms shaping SSD in frogs. Male size was weakly associated with SSD in all size classes, and we found no significant association among SSD, male size, temporal breeding pattern, and male territoriality. In contrast, female size best explained SSD variation across all size classes but especially for small-bodied species. We found a stronger evolutionary association between female body size and fecundity, and this fecundity advantage was highest in explosively breeding species. Our data indicate that the fecundity advantage associated with female body size may not be linear, such that intermediate and large females benefit less with body size increases. Therefore, size-dependent selection in females associated with fecundity and breeding patterns is an important mechanism driving SSD evolution in frogs. Our study underscores the fact that lineage-specific ecology and behavior should be incorporated in comparative analyses of animal SSD. (AU)

• FAPESP's process: 13/04023-5 - Characterization of microsatellite markers for Bokermannohyla ibitiguara (Anura, Hylidae)
• Grantee: Renato Christensen Nali
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 08/50928-1 - Speciation of frogs in high-altitude environments
• Grantee: Célio Fernando Baptista Haddad
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 12/06228-0 - Genetic, morphological and acoustic diversification in populations of an anuran endemic to the Serra da Canastra, Brazil
• Grantee: Renato Christensen Nali
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 10/03656-6 - Reproductive biology of Bokermannohyla ibitiguara (Anura, Hylidae) in streams in Soutwestern Minas Gerais state.
• Grantee: Renato Christensen Nali
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 09/12013-4 - Reproductive ecology of anuran amphibians: an evolutionary perspective
• Grantee: Cynthia Peralta de Almeida Prado
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 13/50741-7 - Diversity and conservation of Brazilian amphibians
• Grantee: Célio Fernando Baptista Haddad
• Support Opportunities: BIOTA-FAPESP Program - Thematic Grants