RUI: Evolutionary Relationships within the Neotropical Frog Genus Leptodactylus

9815787 De Sa我们的星球正经历着物种灭绝的惊人速度，这通常被称为“生物多样性危机”。这方面的一个例子是全世界青蛙种群密度的下降，因此物种灭绝的可能性增加。生物学家迫切需要了解为什么会发生这种情况。为了解决这个问题，我们必须首先知道目前生活着多少物种。此外，如果我们要了解影响物种起源和当前分布的因素，我们必须评估现有物种之间的历史关系。目前的建议是破译南美洲和中美洲的一个大型蛙群，即细趾蛙属的关系。这组青蛙包括大约70种，分为四个谱系。我们知道这四个谱系在6500万到7000万年前就已经存在了，并且彼此分化，但我们不知道这些群体内部或群体之间的关系。这些青蛙展示了一系列不同的繁殖策略，毫无疑问，这些策略有助于它们在过去几百万年里的成功和生存。破译这些青蛙之间的关系是了解它们繁殖策略历史的第一步。我们将使用各种分子技术，目的是收集遗传数据（DNA序列）来评估关系。遗传数据将与以前可用的和新收集的形态学数据相结合。该项目旨在让理科生有机会在参与创造性的科学探究过程中学习分子技术、形态学方法和统计模型。

9815787 De Sa Our planet is currently experiencing an alarming rate of species disappearance, commonly referred to as the 'Biodiversity Crisis.' An example of this is the observance of decline in frog population density around the world, and hence the increased possibility of species extinction. It is urgent that biologists understand why this is happening. To address this we must first know how many species are living currently. Furthermore, we must assess the historical relationships among existing species if we are to understand the factors contributing to their origin and current distributions.The present proposal is to decipher relationships in a large group of South and Central American frogs, the genus Leptodactylus. This group of frogs includes about 70 species in four lineages. We know the four lineages were already present and differentiated from each other about 65-70 million years ago, but we do not know the relationships within or among the groups. These frogs exhibit an array of different reproductive strategies that undoubtedly has contributed to their success and survival over the last several million years. Deciphering the relationships among these frogs represents the first step to understanding the history of their reproductive strategies.We will use a variety of molecular techniques with the purpose of collecting genetic data (DNA sequences) to assess relationships. The genetic data will be integrated with previously available and newly gathered morphological data. The project is designed to give undergraduate science students the opportunity to learn molecular techniques, morphological methodologies, and statistical models within a participatory creative process of scientific inquiry.