Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland.
Mol Ecol. 2012 Feb;21(3):541-53. doi: 10.1111/j.1365-294X.2011.05256.x. Epub 2011 Sep 1.
Environmental change poses challenges to many organisms. The resilience of a species to such change depends on its ability to respond adaptively. Social flexibility is such an adaptive response, whereby individuals of both sexes change their reproductive tactics facultatively in response to fluctuating environmental conditions, leading to changes in the social system. Social flexibility focuses on individual flexibility, and provides a unique opportunity to study both the ultimate and proximate causes of sociality by comparing between solitary and group-living individuals of the same population: why do animals form groups and how is group-living regulated by the environment and the neuro-endocrine system? These key questions have been studied for the past ten years in the striped mouse Rhabdomys pumilio. High population density favours philopatry and group-living, while reproductive competition favours dispersal and solitary-living. Studies of genetic parentage reveal that relative fitness of alternative reproductive tactics depends on the prevailing environment. Tactics have different fitness under constrained ecological conditions, when competitive ability is important. Under conditions with relaxed ecological constraints, alternative tactics can yield equal fitness. Both male and female striped mice display alternative reproductive tactics based on a single strategy, i.e. all individuals follow the same decision rules. These changes are regulated by endocrine mechanisms. Social flexibility is regarded as an adaptation to unpredictably changing environments, selecting for high phenotypic flexibility based on a broad reaction norm, not on genetic polymorphism for specific tactics.
环境变化给许多生物带来了挑战。物种对这种变化的适应能力取决于其适应能力。社会灵活性就是这样一种适应反应，即两性个体根据环境条件的波动，选择灵活地改变其繁殖策略，从而导致社会系统发生变化。社会灵活性侧重于个体的灵活性，通过比较同一群体中独居和群居个体，为研究社会性的终极和近因提供了独特的机会：为什么动物要形成群体，以及环境和神经内分泌系统如何调节群体生活？在过去的十年中，条纹鼠 Rhabdomys pumilio 一直是研究这些关键问题的对象。高种群密度有利于亲代抚育和群居，而繁殖竞争则有利于扩散和独居。对遗传亲子关系的研究表明，替代繁殖策略的相对适应性取决于流行的环境。在竞争能力很重要的受限制的生态条件下，策略具有不同的适应性。在生态限制放宽的条件下，替代策略可以产生相等的适应性。雄性和雌性条纹鼠都表现出基于单一策略的替代繁殖策略，即所有个体都遵循相同的决策规则。这些变化受内分泌机制的调节。社会灵活性被认为是对不可预测的环境变化的一种适应，选择基于广泛反应规范的高表型灵活性，而不是针对特定策略的遗传多态性。
