Dissertation Research: Studies of Diversification in Anolis marmoratus Lizards

Anolis属的蜥蜴是加勒比海地区最常见和最多样化的陆生脊椎动物。尽管对它们的生态、行为和地理分布有广泛的了解，但人们对许多物种种群内和种群之间的遗传变异性水平以及这些水平如何影响物种形成过程知之甚少。形态多样的Anolis marmoratus物种，在小安的列斯瓜德罗佩斯群岛有12个命名亚种，为探索交配系统、遗传变异性水平和涉及形态变化的物种形成之间的关系提供了一个测试案例。本种的变异在成年雄性的颜色和图案上特别明显；特征，连同信号行为，在社会竞争和配偶识别中是重要的。这些性状的变异，导致所谓的分类(即优先)交配，将促进种群间遗传差异的积累，这是导致物种形成(完全生殖隔离)的假定第一步。学院顾问大卫·维克和哈里·格林将指导研究生克里斯托弗·施奈德对这群Anolis蜥蜴的遗传、行为和形态变异进行研究。重点放在精选线粒体基因的核苷酸测序上，以获得变异和种群之间、岛屿内和岛屿之间基因流动的精细证据。这些基因数据将允许对有关雄性颜色模式和展示行为如何影响交配成功的假设进行几次测试，从而帮助构建当地种群的基因结构。反过来，对当地种群遗传结构的了解将有助于检验关于这一多样化蜥蜴群体中物种形成过程的想法。

Lizards of the genus Anolis are the most common and diverse terrestrial vertebrates in the Caribbean. Despite extensive knowledge about their ecology, behavior, and geographical distributions, little is known about levels of genetic variability within and between populations of the many species, and of how these levels affect processes of speciation. The morphologically diverse species Anolis marmoratus, with 12 named subspecies in the Guadeloupean archipelago of the Lesser Antilles, provides a test case for exploring the relationship between mating systems, levels of genetic variability, and speciation involving morphological change. Variation in this species is particularly conspicuous in color and pattern of adult males; characters that, along with signalling behavior, are important in social competition and mate recognition. Variation in these characters, leading to what is called assortative (that is, preferential) mating, will promote the accumulation of genetic differences among populations, a postulated first step leading to speciation (complete reproductive isolation). Faculty advisers David Wake and Harry Greene will supervise graduate student Christopher Schneider in a study of genetic, behavioral, and morphological variation in this group of anolis lizards. Emphasis is placed on nucleotide sequencing of select mitochondrial genes to acquire fine-scale evidence of variation and of gene flow between populations, within islands and between islands. The gene data will allow several tests of hypotheses concerning how male color patterns and display behaviors affect mating success, and thereby help structure local populations genetically. In turn, knowledge about the genetic structure of local populations will help test ideas about speciation processes in this diverse group of lizards.