The evolution of sexual size dimorphism in the house finch. Iv. Population divergence in ontogeny

Alexander V. Badyaev, Geoffrey E. Hill, Linda A. Whittingham

Research output: Contribution to journalArticlepeer-review

31 Scopus citations


Differences among taxa in sexual size dimorphism of adults can be produced by changes in distinct developmental processes and thus may reflect different evolutionary histories. Here we examine whether divergence in sexual dimorphism of adults between recently established Montana and Alabama populations of the house finch (Carpodacus mexicanus) can be attributed to population differences in growth of males and females. In both populations, males and females were similar at hatching, but as a result of sex-specific growth attained sexual size dimorphism by the time of independence. Timing and extent of growth varied between the sexes: Females maintained maximum rates of growth for a longer time than males, whereas males had higher initial growth rates and achieved maximum growth earlier and at smaller sizes than females. Ontogeny of sexual dimorphism differed between populations, but in each population, sexual dimorphism in growth parameters and sexual dimorphism at the time of nest leaving were similar to sexual dimorphism of adults. Variation in growth of females contributed more to population divergence than did growth of males. In each population, we found close correspondence between patterns of sexual dimorphism in growth and population divergence in morphology of adults: Traits that were the most sexually dimorphic in growth in each population contributed the most to population divergence in both sexes. We suggest that sex-specific expression of phenotypic and genetic variation throughout the ontogeny of house finches can result in different responses to selection between males and females of the same age, and thus produce fast population divergence in the sexual size dimorphism.

Original languageEnglish (US)
Pages (from-to)2534-2549
Number of pages16
Issue number12
StatePublished - 2001


  • Growth
  • House finch
  • Molecular sex identification
  • Sexual size dimorphism

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Genetics
  • Agricultural and Biological Sciences(all)


Dive into the research topics of 'The evolution of sexual size dimorphism in the house finch. Iv. Population divergence in ontogeny'. Together they form a unique fingerprint.

Cite this