DISSERTATION RESEARCH: Phylogenomics and Evolutionary Rates associated with Salinity and Thermal Shifts in Centrarchiformes

硬骨鱼比其他任何种类的脊椎动物都要多样化。然而，我们对他们的历史并不清楚。确定是什么导致了这种多样性将极大地帮助我们了解生命是如何在我们的星球上形成的。它还将使我们了解未来的环境扰动如何影响这种多样性。向新的生境类型的过渡，例如从淡水生境向海洋生境的过渡，或从热带向温带的过渡，可能增加了鱼类的多样性。以前的研究已经研究了这些栖息地之间的鱼类过渡，并发现不同数量的支持每个过渡类型的重要性。然而，这些转变只在关系较远的鱼类群体中进行了研究。这项研究将是第一个研究这些栖息地之间的进化过渡在一组相对密切相关的鱼类。这些群体包括熟悉的和经济上重要的物种，如大口黑鲈和太阳鱼。该项目将采用一种新颖的方法来回答两个宏观进化问题：（1）热带和温带栖息地之间，（2）淡水和海洋栖息地之间，中央形目的多样性率是如何变化的？为了回答这些问题，Centralarchiform物种之间的系统发育关系，将解决密集的分类采样和数以千计的非连锁核基因座。将化石校准和用于各种分析，以测试多样化率的变化及其与盐度或热生境过渡的潜在关联。此外，该项目可能会提供有关跨越不同栖息地类型的其他水生种群多样性的总体见解。

Bony fishes are more diverse than any other class of vertebrates. However, we do not have a clear understanding of their history. Determining what led to this diversity will greatly help us understand how life has formed on our planet. It will also allow us to understand how future environmental perturbations might affect this diversity. Transitions to new habitat types, such as from freshwater to marine habitats, or tropical to temperate, may have increased fish diversity. Previous studies have examined the transition of fishes between these habitats and found varying amounts of support for the importance of each transition type. However, these transitions have only been examined in distantly related groups of fishes. This study will be the first to examine the evolutionary transitions between these habitats within a group of relatively closely related fish. These groups contain familiar and economically important species such as largemouth bass and sunfish. Outreach to the public and K-12 students will occur through presentations, social media, and museum displays.This project will take a novel approach to answer two macro-evolutionary questions: How have diversification rates in the Centrarchiformes varied between (1) tropical and temperate habitats and (2) between freshwater and marine habitats? To answer these questions phylogenetic relationships among Centrarchiform species will be resolved using dense taxonomic sampling and thousands of unlinked nuclear loci. The phylogeny will be fossil calibrated and used in a variety of analyses to test for shifts in the diversification rate and their potential associations with salinity or thermal habitat transitions. Furthermore, this project may provide general insight on the diversification of other aquatic groups that span diverse habitat types.