Collaborative Research: Phylogenetic Systematics and the Evolution of Reproductive Innovation in an Adaptive Radiation of Limnonectes Fanged Frogs

当一个物种到达一个空置的区域时，比如一个新形成的岛屿，这个单一的殖民者就有机会辐射到大量的物种，这些物种利用了大量原本空置的生态位。进化生物学家对这些所谓的“适应性辐射”非常感兴趣，因为它们往往戏剧性地展示了进化过程中的一些更重要的特征，包括物种的快速多样化、复杂适应性特征的进化，以及新近衍生的物种避免彼此竞争的机制--以及杂交。具有良好特征的适应性辐射相对罕见，一旦它们被确立为研究的模型系统，往往会被生物生物学家深入研究。经典的适应性辐射的例子包括达尔文雀类、夏威夷银剑植物联盟和东非五大湖特有的慈鱼辐射。这个项目将描述一种新发现的涉及东南亚青蛙的适应性辐射，同时允许对世界上一个研究不足的地区的生物多样性进行详细研究。研究人员将促进代表不足的少数群体参与STEM，特别是学生和职业生涯早期的研究人员。该奖项由国际科学与工程办公室共同资助，因为它将促进跨国界的数据共享和数据互操作性。这项研究将详细描述一种尚未得到充分认识的假定的适应性辐射--印度尼西亚苏拉威西岛和邻近的菲律宾群岛的尖牙蛙--的多样化历史。这个由大约40个物种组成的组合(其中大多数还没有正式命名)展示了许多通常具有适应性辐射特征的特征。例如，石斑鱼的成年体型变化超过350倍，其血统的大小从2克到700克以上不等，还有许多小、中、大和巨型的独立衍生体。苏拉威西和菲律宾各地分布着6个或更多共生物种的群落，这些物种组合似乎划分了微生境，表现出与微生境专门化相关的表型，并在繁殖模式上有很大差异。这项研究将首先使用外显子组捕获下一代测序方法建立该组合的系统发育框架。在这一系统发展的背景下，它将分析身体大小的进化，测试表型特征(形态和生理特征)与微生境专门化之间的相关性，按物种繁殖多样性详细描述该物种，并提供发声行为多样性的分析。这项研究将全面描述这种辐射的生态驱动因素，以及与该组合在东南亚岛屿上显著多样化相关的形态、生理和生活史特征。这个项目将扩大我们的知识面，了解生物体如何利用新的生态机会进行多样化，以及如何由于竞争而快速适应密切相关物种之间巨大的生理差异。

When a species reaches an unoccupied area such as a newly formed island, there is an opportunity for that single colonizer to radiate into a large number of species that exploit the multitude of otherwise unoccupied niches. These so-called 'adaptive radiations' are of profound interest to evolutionary biologists because they often dramatically exemplify some of the more important features of the evolutionary process, including rapid diversification of species, the evolution of complex adaptive traits, and the mechanisms by which recently derived species avoid competition with one another - as well as hybridization. Well-characterized adaptive radiations are relatively rare, and tend to be studied intensively by organismal biologists once they have become established as model systems for study. Examples of classical adaptive radiations include Darwin's Finches, the Hawaiian Silversword alliance of plants, and the cichlid fish radiation endemic to the East African Great Lakes. This project will characterize a newly discovered adaptive radiation involving Southeast Asian frogs, while allowing for a detailed study of biological diversification in an understudied region of the world. The researchers will promote STEM engagement of underrepresented minorities, especially students and early-career researchers. This award is cofunded by the Office of International Science and Engineering because it will advance data sharing and data interoperability across national boundaries.This research will characterize in detail the diversification history of an as yet underappreciated putative adaptive radiation the Limnonectes fanged frogs of the large Indonesian island of Sulawesi and the adjacent Philippines Archipelago. This assemblage of ~40 species (most of which have not yet been formally named) exhibits many of the features that often characterize adaptive radiations. For example, Limnonectes exhibit more than 350-fold variation in adult body size, with lineages ranging in size from 2 grams to more than 700 grams, and many independent derivations of small, medium, large, and giant forms. Communities of six or more sympatric species occur throughout Sulawesi and the Philippines, and these species assemblages appear to partition microhabitats, exhibit phenotypes that correlate with microhabitat specializations, and vary dramatically in reproductive mode. This study will first establish a phylogenetic framework for this assemblage using an exome-capture Next-Generation Sequencing approach. In the context of this phylogeny, it will then provide analyses of body size evolution, test for correlations between phenotypic traits (both morphological and physiological) with microhabitat specializations, describe in detail the species by species reproductive diversity exemplified by this group, and provide an analysis of vocalization behavioral diversity. This research will be fully characterizing ecological drivers of this radiation, as well as the morphological, physiological, and life history features associated with the assemblage's remarkable diversification in insular Southeast Asia. This project will expand our breath of knowledge on how organisms take advantage of new ecological opportunities to diversify, and how adaptations of vast physiological differences between closely related species can evolve very quickly due to competition.