Eco-Evo--Devo and the Origin and Elaboration of a Major Evolutionary Transition

我的研究计划的一个长期目标是了解生物复杂性的起源和发展背后的发育遗传机制。生命的历史以个性的几次主要进化转变为标志，这些转变发生在个体生物联合起来形成更高层次的个体时。这些重大转变的例子包括专性内共生的进化，在这种进化中，一个不相关的宿主和内共生结合形成一个单独的个体，多细胞生物的进化，单细胞原生生物结合形成多细胞生物，以及社会性的进化，在这种进化中，独居昆虫结合形成群居昆虫群体。这种转变被认为在进化过程中推动了生物复杂性的大幅增加，因为它们导致了更高级别的个体在其组成部分之间进行了劳动分工。尽管生物学家已经开始确定个体主要转变中共有的进化原则，但促进其起源和发展的发育遗传机制却知之甚少。

A long-term goal of my research program is to understand the developmental genetic mechanisms underlying both the origins and elaboration of biological complexity. The history of life is marked by several major evolutionary transitions in individuality, which occur when individual organisms unite to form a higher-level individual. Examples of such major transitions include the evolution of obligate endosymbiosis in which an unrelated host and endosymbiont unite to form a single individual, the evolution of multicellularity in which unicellular protists unite to form multicellular organisms, and the evolution of eusociality in which solitary insects unite to form social insect colonies. Such transitions are thought to have driven major increases in biological complexity over the course of evolution because they result in higher-level individuals with a division of labor between their constituent parts. Although biologists have begun identifying evolutionary principles shared across major transitions in individuality, little is known about the developmental genetic mechanisms that facilitated their origin and elaboration. Over the last 6 years, my lab has gained significant momentum to capitalize on several recent discoveries to uncover the developmental genetic mechanisms underlying the origin and elaboration of the transition to eusociality in ants. Ants are one of the most ecologically dominant and evolutionarily successful group of organisms on our planet. Similar to a multicellular organism with its division of labor between germline and somatic cells, an ant colony is equivalent to a superorganism' with a reproductive division of labor between the fertile queen (the germline) and her non-reproductive workers (soma). Understanding the origin and evolution of novel castes within ant colonies may reveal general principles underlying origin and evolution of novel cell types within multicellular organisms. We will begin to uncover the developmental genetic mechanisms underlying the origin and elaboration of the transition to eusociality in ants through three research objectives: Objective 1 will test the hypothesis that programed cell death plays a key role in the origin of a novel winged queen and wingless worker caste. Objective 2 will test the hypothesis that DNA damage response pathway plays a role in elaborating the reproductive asymmetry between the queen and worker caste. Objective 3 will test the hypothesis that the wing rudiments were re-purposed into developmental signaling centers that elaborate the worker caste into a complex worker caste system. My research program has the potential to reveal that the mechanisms involved in the origin of biological complexity also function in its elaboration and will potentially reveal general mechanistic principles shared across different major transitions in individuality. My research program will further serve NSE in Canada by training 7 HQP over the course of the following five years.