Data from: Ecological speciation in dynamic landscapes

Although verbal theories of speciation consider landscape changes, ecological speciation is usually modeled in a fixed geographical arrangement. Yet landscape changes occur, at different spatio-temporal scales, due to geological, climatic or ecological processes, and these changes result in repeated divisions and reconnections of populations. We examine the effect of such landscape dynamics on speciation. We use a stochastic, sexual population model with polygenic inheritance, embedded in a landscape dynamics model (allopatry-sympatry oscillations). We show that, under stabilizing selection, allopatry easily generates diversity, but species coexistence is evolutionarily unsustainable. Allopatry produces refuges whose persistence depends on the characteristic time scales of the landscape dynamics. Under disruptive selection, assuming that sympatric speciation is impossible due to Mendelian inheritance, allopatry is necessary for ecological differentiation. The completion of reproductive isolation, by reinforcement, then requires several sympatric phases. These results demonstrate that the succession of past, current and future geographical arrangements considerably influence the speciation process.

尽管物种形成的描述性理论已将景观变化纳入考量范畴，但生态物种形成的模型通常仍基于固定地理格局构建。然而，地质、气候或生态过程会驱动景观以不同时空尺度发生动态变化，此类变化会导致种群反复出现隔离与连通。本研究探讨此类景观动态对物种形成过程的影响。我们采用嵌入了异域（allopatry）-同域（sympatry）振荡景观动态模型的、具备多基因遗传（polygenic inheritance）特性的有性种群随机模型。研究结果表明，在稳定选择（stabilizing selection）作用下，异域格局易于催生物种多样性，但物种共存在进化层面难以持续；异域格局会形成种群避难所，其存续时长取决于景观动态的特征时间尺度。在歧化选择（disruptive selection）条件下，若假设因孟德尔遗传（Mendelian inheritance）机制无法发生同域物种形成（sympatric speciation），则异域格局是实现生态分化的必要前提；随后，通过强化作用完成生殖隔离，需要经历多轮同域阶段。上述结果证实，过去、当前与未来地理格局的更迭会显著影响物种形成的整个过程。