Ecology and Evolution of Genetic Systems

我的研究项目探索植物种群的生态学和遗传学；即环境中的相互作用，包括人类活动，如何影响种群随着时间的推移而发生的遗传变化，反过来，进化过程和遗传多样性如何影响种群的增长和灭绝。这些过程是了解和管理我们对其他物种的影响、建立可持续的食物来源、控制入侵物种和保护濒危物种的基础。我的专长是*生殖过程的功能和进化，如交配、杂交和多倍体。这些特征在有机体中是高度可变的，并对种群规模、增长和遗传变化有直接影响。*在这个建议中，我重点讨论倍性变异的原因和后果，即每个核的基因组拷贝数。倍性变异在多细胞生物体(配子、肿瘤)中被发现，物种间的变异广泛存在，并与它们的功能、生态和进化的巨大变化有关。我们将通过研究多倍体对新物种形成和适应不断变化的环境的影响，来更全面地理解为什么多倍体在一些生物中如此普遍，而在另一些生物中却不是。我们将研究形成新的多倍体的主要机制，即通过未还原的(2n)配子。这一特征可能并不是在所有物种中都很容易表达，只可能在某些环境中诱导出来。我们还将研究新形成的多倍体与它们的环境之间的相互作用，以确定什么条件使它们能够建立。对于多倍体种群生物学的研究是新颖的，我们利用三个不同物种的自然二倍体新合成的多倍体，这使我们能够观察多倍体在进化的最早阶段的命运。我们将研究一个广泛的假设，即基因组繁殖可以影响并可能加速适应和物种扩散。总而言之，我们的建议将提供一个关键的生态和进化背景，在其中解释倍性的基因组、医学和系统发育研究的爆炸性。

My research program explores the ecology and genetics of plant populations; i.e., how interactions in the environment, including human activity, influence genetic changes in populations over time and, conversely, how evolutionary processes and genetic diversity affect population growth and extinction. These processes are the basis for understanding and managing our influence on other species, building sustainable food sources, controlling invasive species, and conserving species at risk. My specific expertise is on***the function and evolution of reproductive processes such as mating, hybridization, and polyploidy. These characteristics are highly variable among organisms, and have direct effects on population size, growth and genetic change.******In this proposal, I focus on the causes and consequences of variation in ploidy, or the number of genome copies per nucleus. Ploidy variation is found among cells of multicellular organisms (gametes, tumours), and variation among species is widespread and associated with large shifts in their function, ecology and evolution. We will develop a more complete understanding of why polyploidy is so prevalent in some organisms, but not others, by investigating its affects on the formation of new species and adaptation to changing environments. We will examine the primary mechanism by which new polyploids are formed, i.e. through unreduced (2n) gametes. This trait may not be expressed readily in all species and may be induced only in certain environments. We will also examine the interactions between newly formed polyploids and their environments to determine what conditions enable them to establish. Novel to the study of polyploid population biology, we capitalize on newly synthesized polyploids from natural diploids in three different species, which allows us to observe the fate of polyploids in the earliest stages of evolution. We will investigate the broad hypothesis that genome multiplications can influence and possibly accelerate adaptation and species proliferation. Collectively, our proposal will provide a critical ecological &evolutionary context within which to interpret the explosion of genomic, medical and phylogenetic research on ploidy.********************