Evolution of diversity

根据达尔文的说法，多样性的起源是神秘中的神秘。今天有数百万种物种存在，但产生这种多样性的详细机制仍不清楚。传统的物种形成模式是基于地理隔离：如果一个祖先谱系的亚种群在地理上被细分（例如，由于气候变化而分裂），它们就会走上不同的进化轨迹，从而多样化。在这里，最初的基因库分裂过程是不适应的。相反，在适应性物种形成过程中，基因库的分裂本身就是一种适应。在过去的十年里，人们对这种适应性多样化的兴趣越来越大，因为经验和理论研究都证明了它的可行性。进化分支的范式理论推广了多样化可以由生态相互作用（如资源竞争）驱动的概念。利用细菌E.大肠杆菌，我已经开发了一个微生物模型系统，以测试由于进化分支的适应性多样化的理论。E.大肠杆菌有许多优点，包括可以进化数千代，并通过冷冻中间阶段创造化石记录。我们进化的E.由于对碳资源的竞争，大肠杆菌种群经历了多样化。本研究以分子、生理和生态学实验为基础，全面分析了该模式系统适应性多样化过程的各个方面，记录了多样化事件发生前、发生中和发生后的进化变化。我们还在研究不同微生物系统中多样性的起源，其中多样化发生在合作的一般问题的背景下，导致合作者和作弊者在生产有益物质时共存。我们的研究的另一个主要重点是我们的实验模型系统的数学建模的基础上的“反应动力学”的个人，描述个人的成长，繁殖和生存使用从我们的实验中获得的知识。最后，我们计划研究捕食如何影响多样化的实验和数学模型系统。

The origin of diversity is the mystery of mysteries according to Darwin. Millions of species exist today, but the detailed mechanisms generating this diversity are still unclear. The traditional model of speciation is based on geographical isolation: if subpopulations of an ancestral lineage become geographically subdivided (e.g. through fragmentation due to climatic changes), they embark on different evolutionary trajectories, and hence diversify. Here the initial process of splitting the gene pool is not adaptive. In contrast, in the process of adaptive speciation, the splitting of the gene pool is itself an adaptation. The past decade has seen growing interest in such adaptive diversification, because both empirical and theoretical studies have documented its feasibility. The paradigmatic theory of evolutionary branching has popularized the notion that diversification can be driven by ecological interactions such as competition for resources. Using the bacterium E. coli, I have developed a microbial model system to test the theory of adaptive diversification due to evolutionary branching. E. coli offers many advantages, including the possibility of evolving it for thousands of generations and creating a fossil record by freezing intermediate stages. Our evolving E. coli populations have undergone diversification due to competition for carbon resources. Based on molecular, physiological and ecological experiments, my research aims at fully analyzing all aspects of the process of adaptive diversification in this model system, documenting the evolutionary changes prior, during and after the diversification event. We are also studying the origins of diversity in a different microbial system, in which diversification occurs in the context of the general problem of cooperation, leading to coexistence of cooperators and cheaters in the production of a beneficial substance. Another main focus of our research is the mathematical modeling of our experimental model systems based on "reaction kinetics" of individuals, describing individual growth, reproduction and survival using the knowledge gained from our experiments. Finally, we plan to investigate how predation affects diversification in both the experimental and the mathematical model systems.