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区域，比如一个新形成的岛屿时，这个单一的殖民者就有机会辐射到大量的物种，这些物种可以利用大量的无人居住的生态位。这些所谓的“适应性辐射”引起了进化生物学家的极大兴趣，因为它们经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。具有良好特征的适应性辐射是相对罕见的，一旦它们被建立为研究的模型系统，生物生物学家往往会对其进行深入研究。经典的适应性辐射的例子包括达尔文雀，夏威夷银剑植物联盟，以及东非大湖区特有的慈鲷辐射。该项目将描述一种涉及东南亚青蛙的新发现的适应性辐射，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性不足的少数民族，特别是学生和早期职业研究人员参与STEM。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。本研究将详细描述印度尼西亚苏拉威西岛和邻近的菲律宾群岛的Limnonectes尖牙蛙的一种尚未得到充分认识的假定适应性辐射的多样化历史。这个约40个物种的组合（其中大多数尚未正式命名）表现出许多通常表征适应性辐射的特征。例如，Limnonectes在成年体型上表现出超过350倍的变化，其谱系的大小从2克到700多克不等，还有许多独立的小、中、大和巨型的衍生形式。整个苏拉威西岛和菲律宾都有6种或更多的同域物种群落，这些物种组合似乎划分了微栖息地，表现出与微栖息地特化相关的表型，并且在繁殖模式上差异很大。本研究将首先利用外显子组捕获新一代测序方法建立该组合的系统发育框架。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）与微栖息地特化之间的相关性，详细描述以该群体为例的物种的生殖多样性，并提供发声行为多样性的分析。本研究将全面描述这种辐射的生态驱动因素，以及与东南亚岛屿群落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对生物如何利用新的生态机会来多样化的知识的呼吸，以及密切相关的物种之间巨大的生理差异的适应如何由于竞争而迅速进化。

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.