Dynamics of an adaptive radiation: the sigmodontine rodents of South America.

由自然选择引起的物种数量的迅速增加被称为适应性辐射。适应性辐射是进化中最引人注目和最著名的例子。 它们也经常被认为是地球上生命多样性的最重要原因之一，但它们只在少数情况下得到了很好的记录。该项目将揭示自然选择在哺乳动物适应性辐射中的重要性。这将有助于发展新的方法来研究自然选择在进化史上的影响程度。了解自然选择的可预测性将有助于更好地了解物种的许多特征，从生物化学到形态学。区分适应和遗传特征的相对作用将提高任何比较不同物种的研究的效率，例如生物医学研究，使用小鼠，大鼠或其他物种来了解人类健康。该项目还将帮助培养下一代科学家，从高中到研究生和博士后研究人员。数百个物种的三维图像将被发布到网上，供其他研究人员在研究中使用。这些图像将为科学家提供宝贵的数据来源，并将成为教师和学生的宝贵教育工具。该项目将测试哺乳动物中最重要的多样化事件之一，Oryzomyalia分类群，一组超过350种啮齿动物物种，来自700万至1000万年前南美洲的单一殖民地，是否是一种适应性辐射。下一代DNA测序将解决殖民化后早期非常迅速的多样化问题。新的DNA序列数据将被添加到现有数据中，以产生至少330个物种的基本完整的系统发育。将对265个物种的表型的各个方面进行测量，包括牙齿、头骨、四肢、脊椎、皮毛和气候耐受性。基于模型的方法将测试早期快速的表型分化与随后的放缓。将更详细地探索发散模式，测试亚组内的辐射。最后，性状之间的遗传相关性的信息将被用来估计选择的强度，发生在每个分支的generation.This奖项反映了NSF的法定使命，并已被认为是值得的支持，通过评估使用基金会的智力价值和更广泛的影响审查标准。

The rapid increase in the number of species caused by natural selection is known as adaptive radiation. Adaptive radiations are the most dramatic and well-known examples of evolution. They are also often thought to be one of the most important causes of the diversity of life on Earth, but they have only been well documented in a small number of cases. This project will reveal how important natural selection may have been in the adaptive radiation of mammals. It will help develop new methods to study the degree of influence of natural selection in evolutionary history. Understanding how predictable natural selection has been would allow a much better understanding of many features of a species, from its biochemistry to its morphology. Teasing apart the relative roles of adaptation and inherited traits will improve the efficiency of any research that compares different species, such as biomedical studies, using mice, rats, or other species, to understand human health. This project will also help train the next generation of scientists, from high school to graduate students and post-doctoral researchers. Three-dimensional images of hundreds of species will be posted online and made available to other researchers to use in their studies. These images will provide a valuable source of data for scientists and will be a valuable educational tool for teachers and students.This project will test whether one of the most important diversification events in mammals, the taxon Oryzomyalia, a group of over 350 rodent species that descended from a single colonization of South America 7-10 million years ago, was an adaptive radiation. Next-generation DNA sequencing will resolve the very rapid diversification early after colonization. New DNA sequence data will be added to existing data to yield a largely complete phylogeny of at least 330 species. Diverse aspects of their phenotype, including teeth, skull,limbs, vertebrae, fur, and climatic tolerances, will be measured for 265 species. Model-based methods will test for an early rapid phenotypic divergence with subsequent slow-down. Divergence patterns will be explored in finer detail, testing for radiations within subgroups. Finally, information on the genetic correlations among traits will be used to estimate the strength of selection that occurred on each branch of the phylogeny.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.