We observe closely related species in sympatry and infer how they evolved from a common ancestor. Peter R. Grant More Quotes by Peter R. Grant More Quotes From Peter R. Grant Closely related species of birds are also chromosomally similar. Peter R. Grant birds also related species Thus the genetic basis to the origin of bird species is to be sought in the inheritance of adult traits that are subject to natural and sexual selection. Peter R. Grant adult inheritance natural bird Males transmit signals in courtship through behavioral displays. Peter R. Grant behavioral through courtship signals Species can be recognized by their morphological characteristics and songs. Peter R. Grant songs species characteristics Thus mating of females was strictly along the lines of paternal song. Peter R. Grant strictly along lines song The independent role of morphology in mate choice is revealed by the rare instances where the usual association between song and morphology is disrupted. Peter R. Grant rare choice independent song To summarize, the particular song a male sings, and the behavioral responses of females to song and morphological signals, are not genetically inherited in a fixed manner but are determined by learning early in life. Peter R. Grant early learning song life Genes that underlie the capacity to receive, use and transmit information are the evolving properties. Peter R. Grant genes information capacity use Exchange of breeding individuals between two populations tends to homogenize their gene pools. Peter R. Grant exchange between breeding two The divergence of songs in the new population away from those in the progenitor population would only be prevented if these processes were balanced by repeated immigration and subsequent breeding: song flow. Peter R. Grant new immigration flow song Islands are known to differ in the food supply available to ground finches, mainly seeds. Peter R. Grant ground seeds available food Plumage features constitute a major component of courtship signals. Peter R. Grant constitute major courtship signals Evidence of epistasis from hybridization studies is more scarce. Peter R. Grant studies more scarce evidence Almost nothing is known from hybridization studies about the inheritance of courtship behavior of females, or of their responsiveness to particular male signals. Peter R. Grant about nothing inheritance behavior The theory of founder effects does not explain how novel features like plumage traits arise. Peter R. Grant explain how like theory The process of speciation is completed with the cessation of genetic exchange. Peter R. Grant completed genetic exchange process
