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无人居住的地区（例如新形成的岛屿）时，该单一殖民者就有机会辐射到大量物种，这些物种利用大量其他无人居住的生态位。这些所谓的“适应性辐射”引起了进化生物学家的浓厚兴趣，因为它们常常戏剧性地例证了进化过程中一些更重要的特征，包括物种的快速多样化、复杂适应性特征的进化，以及最近衍生的物种避免相互竞争的机制以及杂交。特征明确的适应性辐射相对罕见，一旦被建立为研究模型系统，有机生物学家往往会对其进行深入研究。经典适应性辐射的例子包括达尔文雀、夏威夷银剑植物联盟和东非五大湖特有的丽鱼辐射。该项目将描述一种新发现的涉及东南亚青蛙的适应性辐射，同时允许对世界上未被充分研究的地区的生物多样性进行详细研究。 研究人员将促进代表性不足的少数群体，特别是学生和早期职业研究人员对 STEM 的参与。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印度尼西亚苏拉威西大岛和邻近菲律宾群岛的利姆诺克特斯长牙青蛙的多样化历史，该青蛙尚未得到充分认识。这个由大约 40 个物种组成的集合体（其中大多数尚未被正式命名）表现出许多通常表征适应性辐射的特征。例如，Limnonectes 的成年体型表现出超过 350 倍的变异，其谱系的体型大小从 2 克到超过 700 克不等，并且有许多独立的小型、中型、大型和巨型形态。六个或更多同域物种的群落遍布苏拉威西岛和菲律宾，这些物种组合似乎划分了微生境，表现出与微生境特化相关的表型，并且在繁殖模式上差异很大。这项研究将首先使用外显子组捕获下一代测序方法为该组合建立系统发育框架。在这种系统发育的背景下，它将提供体型进化的分析，测试表型特征（形态和生理）与微生境特化之间的相关性，详细描述该群体所例证的物种繁殖多样性，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，以及与东南亚岛屿生物群落显着多样化相关的形态、生理和生活史特征。该项目将扩大我们对生物体如何利用新的生态机会实现多样化，以及密切相关的物种之间巨大的生理差异如何因竞争而快速进化的知识。

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.