生态位构建对具有资源竞争物种的进化分布动态的影响

The effects of trait-mediated niche construction on evolutionary distribution dynamics of species with resource competition

生态位构建是有机体通过自身活动、代谢等行为调节或影响其环境或其他生物有机体的过程,进而导致有机体在自然选择过程中产生不同的进化轨迹。已有研究结论是基于双位点种群遗传模型、基于个体模型以及及元胞自动机模拟模型得出的。目前分析物种进化入侵的常用方法之一是进化分布动态模型。通过引入该方法,着重研究了依特征调节的生态位构建作用对具有种内资源竞争的物种进化动态的影响。结果表明:依特征调节的生态位构建确实能够引起物种进化轨迹的明显改变。若生态位构建中心位于特征值较小的特征时,将减少进化分支,且相较于不存在生态位构建的情况而言,种群密度提高;与此相反,生态位构建中心为特征值较大的特征时,生态位构建维持进化多样性,尽管其破坏了原有进化的对称分布。这意味着生态位构建通过与环境长期的正反馈作用,使具有较强依赖的种群特征出现明显差异,分支数虽有减少,但显著提升了优势特征的种群密度,且物种进化分支数随着构建强度的增加而减少。强烈的种内竞争和较弱的生态位构建作用将有利于维持种群的进化多样性。

Niche construction refers to the process in which organisms regulate or influence their environments or other biological organisms through their own movement and metabolism, thus leading to different evolutionary trajectories of organisms in the process of natural selection. These conclusions were drawn based on the two-locus genetic models or mathematical ecological models that built with individual-based model(IBM) or cellular automata(CA) simulation methods. At present, the evolutionary distribution dynamics model is one of the popular methods to analyze the evolutionary invasion. By introducing this approach, we investigated the influence of trait-mediated niche construction on the evolution dynamics of species with intraspecific resource competition. The results confirmed that the niche construction mediated by traits caused obvious changes in the evolutionary trajectory of species. Comparing to the situation without the niche construction, the evolutionary branching reduced and the population density increased when the niche construction center was located in the small trait. While the niche construction acted on the large trait, it could maintain the evolutionary diversity, although the symmetrical evolutionary distribution of classical model was broken. It means that niche construction made significant differences in species traits through the long-term strong positive feedback with their environment. With the increasing of niche-constructing intensity, the species density of dominant traits increased significantly and the number of evolutionary branching decreased. Strong intraspecific competition and weak niche construction would be beneficial to maintain the evolutionary diversity of the species.