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——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——独居昆虫结合形成群居昆虫群落。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。在过去的6年里，我的实验室已经获得了巨大的动力，利用最近的几项发现，揭示了蚂蚁向群居性过渡的起源和发展的遗传机制。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之间分工的多细胞生物类似，蚁群相当于一个“超级有机体”，在可育的蚁后（生殖细胞）和非生殖工蚁（体细胞）之间进行生殖分工。了解蚁群中新阶层的起源和进化，可以揭示多细胞生物中新细胞类型起源和进化的一般原理。我们将通过三个研究目标开始揭示蚂蚁向群居性过渡的起源和阐述的发育遗传机制：目标1将检验程序性细胞死亡在新型有翼蚁后和无翼工蚁种姓的起源中起关键作用的假设。目的2将检验DNA损伤反应途径在蚁后和工蜂的生殖不对称中发挥作用的假设。目标3将验证翅膀雏形被重新利用为发育信号中心的假设，这些信号中心将工人种姓精心设计成一个复杂的工人种姓系统。我的研究项目有可能揭示生物复杂性起源的机制也在其细化过程中发挥作用，并有可能揭示个性不同主要转变中共有的一般机制原则。我的研究项目将在接下来的五年里通过培训7名HQP进一步为加拿大的NSE服务。

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.