When an animal?s environment changes, interrelated biological characteristics of the animal may also change. Hormones such as testosterone [T], the secretion of which is influenced by the environment, coordinate the expression of many traits including sexual, aggressive, and parental behavior, ornamentation, and immune function. Together these traits form the animal?s phenotype, and linkages between hormones and phenotype may play a central role in facilitating or constraining an animal?s ability to respond to environmental change. This research takes advantage of the colonization of an urban environment by a songbird population to compare hormone-phenotype linkages in the new urban environment to those observed in the nearby ancestral environment. This comparison will test whether traits observed in the two environments indicate ?evolutionarily integrated? or ?evolutionarily independent? linkages between T and target traits. The research also will evaluate whether observed changes in traits represent non-genetic developmental alteration or rapid (genetic) evolution.
In an age of rapid global change and habitat alteration, understanding how individuals and populations respond to novel environments has become critical. The research described in this proposal will add to the basic understanding of how and whether vertebrates adapt to novel environments over very rapid time scales (<30yrs). The research will also enhance the training of more than a dozen future scientists, including those from underrepresented groups.
