Loners-individuals out of sync with a coordinated majority-occur frequently in nature. Are loners incidental byproducts of large-scale coordination attempts, or are they part of a mosaic of life-history strategies? Here, we provide empirical evidence of naturally occurring heritable variation in loner behavior in the model social amoeba Dictyostelium discoideum. We propose that Dictyostelium loners-cells that do not join the multicellular life stage-arise from a dynamic population-partitioning process, the result of each cell making a stochastic, signal-based decision. We find evidence that this imperfectly synchronized multicellular development is affected by both abiotic (environmental porosity) and biotic (signaling) factors. Finally, we predict theoretically that when a pair of strains differing in their partitioning behavior coaggregate, cross-signaling impacts slime-mold diversity across spatiotemporal scales. Our findings suggest that loners could be critical to understanding collective and social behaviors, multicellular development, and ecological dynamics in D. discoideum. More broadly, across taxa, imperfect coordination of collective behaviors might be adaptive by enabling diversification of life-history strategies.

中文翻译：

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“孤独者”的生态进化意义。

独来独往的人与协调一致的多数不同步，本质上经常发生。孤独者是大规模协调尝试的附带产物吗？还是生活史策略的一部分？在这里，我们提供了在模型社交变形虫盘基网柄菌盘状模型中独来独往行为的自然发生的遗传变异的经验证据。我们建议，不参与多细胞生命阶段的双歧杆菌孤细胞来自动态的种群分配过程，每个细胞的结果都是基于信号的随机决策。我们发现有证据表明，这种非完全同步的多细胞发育受非生物（环境孔隙度）和生物（信号）因素的影响。最后，我们从理论上预测，当一对菌株的分区行为不同时，它们会聚集在一起，跨信号影响跨时空尺度的粘液霉菌多样性。我们的研究结果表明，孤独者对于了解迪斯科圆盘菌的集体和社会行为，多细胞发育和生态动力学可能至关重要。更广泛地讲，在整个分类单元中，集体行为的不完美协调可能会通过使生活史策略多样化而适应。