Research Starter Grant-Distribution of Genetic Variation in a Recently Derived Adaptive Trait

Louisiana State University, Baton Rouge LA

Investigators

Abstract

The development of new biotechnologies such as the polymerase chain reaction (PCR) and automated DNA sequencing have greatly facilitated the ability of basic researchers to study genetic variation. New genetic markers of potentially great relevance to biologists are known as single nucleotide polymorphisms (SNPs). To put them to the test, Robb Brumfield, in his NSF Research Starter Grant, proposes to use SNPs (pronounced "snips") to understand the evolutionary history of a group of brilliantly plumaged birds known as manakins that inhabit the rainforests of the New World Tropics. Previous studies of these birds have found that hybridization and sexual selection have both played important roles in their speciation. SNPs should provide the needed resolution to determine which process has played the more important role. Brumfield's results will provide insights into the evolution of secondary sexual traits (i.e. traits that evolve because females prefer them but which are not necessarily in the best interest of the male for survival; a male peacock's tail is a good example). Because secondary sexual traits could evolve directly by female's desiring those traits or indirectly through hybridization with a closely related species that has a desirable trait, disentangling the relative importance of those processes is critical for a detailed understanding of their evolution. Brumfield's results should also help other biologists determine whether SNPs represent the best type of genetic marker for their own evolutionary studies of natural populations.