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阐述背后的发育遗传机制。生命的历史以个体的几次重大进化转变为标志，这些转变发生在个体有机体联合起来形成更高层次的个体时。这种主要转变的例子包括专性内共生的进化-其中不相关的宿主和内共生体联合形成单个个体，多细胞的进化-其中单细胞原生生物联合形成多细胞生物，以及真社会性的进化-其中孤独的昆虫联合形成社会性昆虫群体。这种转变被认为是在进化过程中推动生物复杂性大幅增加的原因，因为它们导致了更高层次的个体，并在其组成部分之间进行了分工。虽然生物学家已经开始确定在个体的主要转变中共享的进化原则，但对促进其起源和发展的发育遗传机制知之甚少。 在过去的6年里，我的实验室获得了巨大的动力，利用最近的几项发现来揭示蚂蚁向真社会性转变的起源和发展背后的发育遗传机制。蚂蚁是地球上最具生态优势和进化成功的生物群体之一。与生殖细胞和体细胞分工的多细胞有机体类似，蚁群相当于一个“超级有机体”，在能生育的蚁后（生殖细胞）和她的非生殖工蚁（索马）之间进行生殖分工。了解蚁群中新种姓的起源和进化可能揭示多细胞生物中新细胞类型起源和进化的一般原则。 我们将开始通过三个研究目标来揭示蚂蚁向真社会性转变的起源和发展的遗传机制：目标1将检验程序性细胞死亡在一种新的有翼女王和无翼工人种姓的起源中起关键作用的假设。目的2将检验DNA损伤反应途径在阐述蜂王和工蜂等级间生殖不对称性中的作用。目的3将测试的假设，翅膀雏形被重新利用到发展的信号中心，阐述了工人种姓到一个复杂的工人种姓制度。我的研究计划有可能揭示生物复杂性起源中涉及的机制也在其阐述中发挥作用，并可能揭示个体不同主要转变中共享的一般机械原理。我的研究计划将在接下来的五年里通过培训7名HQP来进一步服务于加拿大的NSE。

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.