“What determines species diversity” is still a core problem in evolutionary biology. The classical speciation theory emphasizes the role of geographical isolation in the formation of biodiversity. However, the sympatric speciation is neglected due to theoretical difficulties. In this talk, by using the method of adaptive dynamics, we will talk about how the adaptive evolution of defense ability promotes the diversity of prey species in an initial one-prey–two-predator community. We assume that the prey species can evolve to a safer strategy such that it can reduce the predation risk, but a prey with a high defense ability for one predator may have a low defense ability for the other and vice versa. Firstly, by using the method of critical function analysis, we find that if the trade-off is convex in the vicinity of the evolutionarily singular strategy, then this singular strategy is a continuously stable strategy. However, if the trade-off is weakly concave near the singular strategy and the competition between the two predators is relatively weak, then the singular strategy may be an evolutionary branching point. Secondly, we find that after the branching has occurred in the prey strategy, if the trade-off curve is globally concave, then the prey species might eventually evolve into two specialists, each caught by only one predator species. However, if the trade-off curve is convex–concave–convex, the prey species might eventually branch into two partial specialists, each being caught by both of the two predators and they can stably coexist on the much longer evolutionary timescale. I will also talk about our recent research progress on evolutionary dynamics of biodiversity.
祖建，2011年3月获得日本明治大学理学博士学位，目前是西安交通大学数学与统计学院教授、博士生导师，院长助理。陕西省科技奖励评审专家，教育部学位中心学位论文通讯评议专家。主要从事传染病动力学、生物演化动力学和精准医学的数学理论与方法研究。应用演化对策理论、动力系统理论和计算机模拟等方法，研究了生物表型多样性形成、维持与丧失的演化动力学机制。结合我国4次乙肝血清流行病学调查数据系统研究了我国乙肝的流行趋势和防治效果。在Scientific Reports、BMC Bioinformatics、Journal of Theoretical Biology等国际权威杂志发表SCI论文24篇。主持研究教育部高等教育司教学研究课题1项；主持研究国家自然科学基金项目3项；主持研究陕西省自然科学基础研究计划项目等省部级科研项目4项；参与研究“艾滋病和病毒性肝炎等重大传染病防治”科技重大专项项目和国家自然科学基金重点项目等5项。担任国际杂志《International Journal of Evolution》编委。