Evolution of populations expanding on curved surfaces
Evolution of populations expanding on curved surfaces
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DOI：
10.1209/0295-5075/123/58005
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发表时间：
2018-09-01
期刊：
影响因子：
1.8
通讯作者：
Mobius, Wolfram
中科院分区：
文献类型：
--
作者：
Beller, Daniel A.;Alards, Kim M. J.;Mobius, Wolfram
一个种群向新栖息地的扩张是一个短暂的过程，它在不断扩张的种群的基因组成中留下了足迹。环境结构是如何塑造种群前沿的，以及在这种范围扩张过程中的进化动态，人们知之甚少。在这里，我们研究了由许多选择性中性基因型组成的种群在曲面上扩展的进化动力学。结合基于个体的非点阵模拟、几何参数和基于点阵的踏脚石模拟，我们描述了在平坦表面上个体碰撞的影响。与平面上范围扩大的情况相比，我们观察到种群前沿中性遗传多样性的短暂相对增加，然后下降。此外，我们发现，在凸起两侧的个体有显著增加的预期后代数量，而靠近凸起中心的邻居则远没有那么幸运。这两种观测都可以用曲面上直线路径（测地线）的解析描述来解释。补充了先前对异质平坦环境的研究，这里的发现建立了我们对复杂环境如何塑造不断扩大的种群的进化动态的理解。
The expansion of a population into new habitat is a transient process that leaves its footprints in the genetic composition of the expanding population. How the structure of the environment shapes the population front and the evolutionary dynamics during such a range expansion is little understood. Here, we investigate the evolutionary dynamics of populations consisting of many selectively neutral genotypes expanding on curved surfaces. Using a combination of individual-based off-lattice simulations, geometrical arguments, and lattice-based stepping-stone simulations, we characterise the effect of individual bumps on an otherwise flat surface. Compared to the case of a range expansion on a flat surface, we observe a transient relative increase, followed by a decrease, in neutral genetic diversity at the population front. In addition, we find that individuals at the sides of the bump have a dramatically increased expected number of descendants, while their neighbours closer to the bump's centre are far less lucky. Both observations can be explained using an analytical description of straight paths (geodesics) on the curved surface. Complementing previous studies of heterogeneous flat environments, the findings here build our understanding of how complex environments shape the evolutionary dynamics of expanding populations.