Peter R. Grant
Peter R. Grant
Peter Raymond Grant FRS and Barbara Rosemary Grant FRS, a married couple, are both British evolutionary biologists at Princeton University; each holds the position of Emeritus Professor. They are noted for their work concerning Darwin's finches on the Galápagos Island named Daphne Major. The Grants have spent six months of the year each year since 1973 capturing, tagging, and taking blood samples of the finches on the island...
NationalityAmerican
ProfessionScientist
CountryUnited States of America
females strictly thus
Thus mating of females was strictly along the lines of paternal song.
choice mate rare revealed role song usual
The independent role of morphology in mate choice is revealed by the rare instances where the usual association between song and morphology is disrupted.
Species can be recognized by their morphological characteristics and songs.
available differ food islands known mainly supply
Islands are known to differ in the food supply available to ground finches, mainly seeds.
balanced processes repeated songs
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.
information transmit
Genes that underlie the capacity to receive, use and transmit information are the evolving properties.
tends
Exchange of breeding individuals between two populations tends to homogenize their gene pools.
Evidence of epistasis from hybridization studies is more scarce.
closely related
Closely related species of birds are also chromosomally similar.
effects features founder theory
The theory of founder effects does not explain how novel features like plumage traits arise.
behavioral determined early females fixed inherited learning life male manner particular responses
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.
cessation completed
The process of speciation is completed with the cessation of genetic exchange.
basis natural origin sexual sought species subject thus traits
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.
constitute courtship features major
Plumage features constitute a major component of courtship signals.