Exploring the genomics of convergent snout elongations in deep-sea fishes

解释相似特征是如何在远亲生物体中独立进化的，是进化生物学的中心目标。在脊椎动物中，鱼类是少数几个能够反复适应深海海洋环境的进化系统之一，深海海洋环境是地球上最极端、最未被探索的环境之一。从浅海栖息地向深海栖息地的过渡已经发生了多次，导致了各种显著的适应，从生物发光的存在和小的身体尺寸到各种不同的形态专业化。然而，对反复出现在深海中的特殊表型新奇物种的起源和基因组基础进行详细的比较研究，仍然知之甚少。该项目旨在开发一种比较的方法来研究深海刺鱼(三角棘鱼科，四齿目)的汇聚形态进化及其潜在的生态和基因组基础。刺鱼分布于世界海洋的热带和温带上坡，为研究汇聚进化提供了一个杰出的系统，因为该群体的谱系独立进化了至少两次鱼类生命树中最极端的管状鼻子伸长，拥有一些最小的脊椎动物基因组，包括始新世和渐新世保存完好的化石物种。将最先进的基因组和形态数据与现存物种和化石物种的研究相结合，将允许在基因组和生态框架内探索收敛的形态进化的新方法。此外，在分子水平上了解深海会聚的决定因素，有可能为适应和沿海洋深度梯度的形态预测提供一般原则。总体而言，该项目将贡献全基因组重测序数据、现存和化石分类群的CT扫描，以及三棘目和同类的良好解决的系统发生学。该项目还将提供在线视频、教程、互动应用程序、博物馆展品、本科生和研究生培训，以及一系列综合研究论文，探讨表型和基因型之间的联系，以及参与鱼类形态适应的基因组区域之间的关联。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Explaining how similar traits have independently evolved in distantly related organisms is a central goal of evolutionary biology. Among vertebrates, fishes are one of the few evolutionary systems that provide repeated cases of adaptation to deep-sea marine environments, one of the most extreme and underexplored environments on earth. Transitions from shallow to deep-sea habitats have occurred multiple times, resulting in a variety of remarkable adaptations, from the presence of bioluminescence and small body size to a diverse array of morphological specializations. However, detailed comparative studies investigating the origin and genomic bases of specialized phenotypic novelties that have repeatedly appeared in the deep-sea continue to be poorly understood. This project aims to develop a comparative approach to study convergent morphological evolution and its underlying ecological and genomic bases in the deep-sea spikefishes (Triacanthodidae, Tetraodontiformes), which are distributed around the tropical and temperate upper slopes of the world’s oceans.Spikefishes provide an outstanding system for investigating convergent evolution as lineages in the group have independently evolved at least twice the most extreme tubular snout elongation in the Fish Tree of Life, have some of the smallest vertebrate genomes, and included well-preserved fossil species from the Eocene and Oligocene. The integration of state-of-the-art genomic and morphological data with the study of extant and fossil species will allow new ways of exploring convergent morphological evolution in a genomic and ecological framework. Moreover, understanding the determinants of deep-sea convergence at the molecular level has the potential to inform general principles of adaptation and morphological predictivity along ocean depth gradients. Overall, this project will contribute whole-genome resequencing data, CT-scans for extant and fossil taxa, and a well-resolved phylogeny of triacanthodids and allies. This project will also provide online videos, tutorials, interactive apps, museum exhibits, undergraduate and graduate training, and a series of integrative research papers exploring the links between phenotype and genotype and the associations of genomic regions involved in morphological adaptations in fishes.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.