The Evolution of Stable Intermediate Levels of Reproductive Isolation

当独特但相关的物种在地理上相互重叠时，有特定的条件决定它们是融合成一个物种（一种灭绝形式），还是能够进化出阻止它们之间基因交换的机制。这项研究调查了允许第三种可能性的条件，即两个物种可能达到一种稳定的状态，在这种状态下它们仍然交换一些基因，但仍然能够保留它们的特定身份。研究小组将在确定这些部分隔离稳定状态存在的初始模型的基础上进行扩展，使用精确复制种群间迁移、差异生存和配偶选择影响的数学模型。具体来说，PI和其他人的初始模型将以几种方式进行扩展，以允许其他现象，从而大大扩展其适用性。描绘可能导致部分隔离的条件对于发展对物种如何保持彼此区别的基本理解以及理解物种之间地理障碍破裂的可能后果（这是在人类干扰下日益常见的现象）非常重要。作为该项目的一部分，PI将继续在北卡罗来纳大学的入门生物学课程中开发“数学轨道”，该课程使用各种技术来减少数学焦虑，这一问题被证明对女性的表现有不成比例的影响。因此，这条赛道既促进了女性对数学科学的参与，也更广泛地解决了将数学融入本科生物学课程的需要。

When unique but related species overlap geographically with one another, there are specific conditions that determine whether they will fuse into one species (a form of extinction), or will be able to evolve mechanisms to prevent the exchange of genes between them. This research investigates conditions that allow a third possibility, that two species may reach a stable state where they still exchange some genes, but are yet able to retain their specific identities. The research team will expand upon initial models that identified the existence of these stable states of partial isolation, using mathematical models that exactly replicate the effects of migration between populations, differential survival, and mate choice. Specifically, initial models by the PI and others will be extended in several ways to allow for additional phenomena that greatly extend their applicability. Delineating the conditions that can lead to partial isolation is important both in developing a basic understanding of how species can remain distinct from one another, and in comprehending the possible consequences of the breakdown of geographic barriers between species, an increasingly common occurrence under human disturbance. As part of this project, the PI will continue to develop a "mathematical track" in an introductory biology course at UNC, which uses a variety of techniques to reduce math anxiety, a problem documented to disproportionally affect the performance of women. This track thus promotes both the participation of women in the mathematical sciences and more generally addresses the need to integrate math into the undergraduate biology curriculum.