The growth and evolution of microbial populations is often subjected to advection by fluid flows in spatially extended environments, with immediate consequences for questions of spatial population genetics in marine ecology, planktonic diversity and origin of life scenarios. Here, we review recent progress made in understanding this rich problem in the simplified setting of two competing genetic microbial strains subjected to fluid flows. As a pedagogical example we focus on antagonsim, i.e., two killer microorganism strains, each secreting toxins that impede the growth of their competitors (competitive exclusion), in the presence of stationary fluid flows. By solving two coupled reaction–diffusion equations that include advection by simple steady cellular flows composed of characteristic flow motifs in two dimensions (2D), we show how local flow shear and compressibility effects can interact with selective advantage to have a dramatic influence on genetic competition and fixation in spatially distributed populations. We analyze several 1D and 2D flow geometries including sources, sinks, vortices and saddles, and show how simple analytical models of the dynamics of the genetic interface can be used to shed light on the nucleation, coexistence and flow-driven instabilities of genetic drops. By exploiting an analogy with phase separation with nonconserved order parameters, we uncover how these genetic drops harness fluid flows for novel evolutionary strategies, even in the presence of number fluctuations, as confirmed by agent-based simulations as well.

中文翻译：

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具有流体流动的空间种群遗传学

微生物种群的生长和进化经常受到空间扩展环境中流体流动的平流作用，对海洋生态学、浮游生物多样性和生命起源场景中的空间种群遗传学问题产生直接影响。在这里，我们回顾了在两种受流体流动影响的竞争性遗传微生物菌株的简化设置中理解这一丰富问题的最新进展。作为一个教学示例，我们专注于拮抗剂，即两种杀手微生物菌株，在静止流体流动的情况下，每种菌株都分泌阻碍其竞争对手生长的毒素（竞争排斥）。通过求解两个耦合反应扩散方程，其中包括由二维 (2D) 特征流动图案组成的简单稳定元胞流的平流，我们展示了局部流动剪切和可压缩性效应如何与选择优势相互作用，从而对空间分布种群的遗传竞争和固定产生巨大影响。我们分析了几个一维和二维流动几何结构，包括源、汇、涡流和鞍座，并展示了如何使用简单的遗传界面动力学分析模型来阐明遗传滴的成核、共存和流动驱动的不稳定性。通过利用具有非守恒序参数的相分离进行类比，我们揭示了这些 并展示如何使用简单的遗传界面动力学分析模型来阐明遗传滴的成核、共存和流动驱动的不稳定性。通过利用具有非守恒序参数的相分离进行类比，我们揭示了这些 并展示如何使用简单的遗传界面动力学分析模型来阐明遗传滴的成核、共存和流动驱动的不稳定性。通过利用具有非守恒序参数的相分离进行类比，我们揭示了这些遗传的即使在存在数量波动的情况下，也会为新的进化策略放弃利用流体流，这也被基于代理的模拟所证实。