DISSERTATION RESEARCH: Assessing early molluscan evolution with emphasis on aplacophorans

据估计，软体动物有20万种，是物种第二丰富的动物群体。许多软体动物在经济、生态或生物医学上都很重要。此外，软体动物的身体结构非常多样，从蛞蝓到蛤蜊再到巨型乌贼。由于化石记录中软体动物的多样性、多样性和丰富性，近200年来，人们对确定软体动物的原始状态产生了极大的兴趣。长时间以来，人们一直认为这种类蠕虫的软体动物类群对理解早期软体动物的进化很重要。然而，对这个主要是深海群体的进化史（系统发育）知之甚少。本研究旨在结合传统和尖端的下一代DNA测序技术重建placophhoran的系统发育。利用传统的显微镜技术收集新的形态学数据，并将特征映射到系统发育上，以推断出盘虫目以及整个软体动物的原始特征。古生物学家和无脊椎生物学家长期以来一直试图了解这种多样化和迷人的群体的早期进化，了解这些动物是如何进化的，这将对他们产生极大的兴趣。此外，由于软体动物是神经生物学和寄生虫学领域的重要模型，这项工作的结果将直接为生物医学研究提供信息。

With an estimated 200,000 living species, Mollusca is the second most species-rich animal group. Many molluscs are economically, ecologically, or biomedically important. Additionally, the molluscan body plan is extremely varied, ranging from slugs to clams to giant squid. Because of molluscs' variation, diversity and abundance in the fossil record, there has been great interest in identifying the primitive condition of the group for nearly 200 years. The worm-like mollusc group called Aplacophora (Latin for "without a shell") has long been thought to be important to understanding early molluscan evolution. However, little is known about the evolutionary history (phylogeny) within this mostly deep-sea group. This research aims to reconstruct aplacophoran phylogeny using a combination of traditional and cutting-edge, next-generation DNA sequencing technologies. New morphological data will be collected using traditional microscopy and characters will be mapped onto the phylogeny to infer primitive features of Aplacophora as well as Mollusca as a whole. Understanding how these animals have evolved will be of great interest to paleontologists and invertebrate biologists who have long sought to understand the early evolution of this diverse and fascinating group. Moreover, as molluscs are important models in the fields of neurobiology and parasitology, the results of this work will directly inform biomedical research.