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

聚合酶链式反应和DNA自动测序等新生物技术的发展极大地促进了基础研究人员研究遗传变异的能力。与生物学家密切相关的新遗传标记称为单核苷酸多态(SNPs)。为了对它们进行测试，Robb Brumfield在他的NSF Research Starter Grant中提议使用SNPs(发音为snips)来了解一群生活在新大陆热带热带雨林的羽毛鲜艳的鸟的进化史。之前对这些鸟类的研究发现，杂交和性别选择都在它们的物种形成中发挥了重要作用。SNPs应该提供所需的解决方案，以确定哪个过程起到了更重要的作用。Brumfield的结果将为第二性特征(即因为雌性更喜欢它们而进化，但不一定符合雄性生存的最佳利益的特征；雄性孔雀尾巴就是一个很好的例子)的进化提供见解。由于第二性征可以通过雌性渴望这些特征而直接进化，也可以通过与具有理想特征的密切相关物种的杂交间接进化，因此弄清这些过程的相对重要性对于详细了解它们的进化至关重要。Brumfield的结果也应该帮助其他生物学家确定SNPs是否代表了他们自己对自然种群进化研究的最佳遗传标记类型。

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.