DiRienzo Nicholas, Johnson J Chadwick, Dornhaus Anna
Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA.
School of Mathematical and Natural Sciences, Arizona State University, Glendale, AZ, USA.
Behav Ecol. 2019 Mar-Apr;30(2):455-464. doi: 10.1093/beheco/ary185. Epub 2018 Dec 21.
Developmental plasticity is known to influence the mean behavioral phenotype of a population. Yet, studies on how developmental plasticity shapes patterns of variation within populations are comparatively rare and often focus on a subset of developmental cues (e.g., nutrition). One potentially important but understudied developmental experience is social experience, as it is explicitly hypothesized to increase variation among individuals as a way to promote "social niches." To test this, we exposed juvenile black widow spiders () to the silk of conspecifics by transplanting them onto conspecific webs for 48 h once a week until adulthood. We also utilized an untouched control group as well as a disturbed group. This latter group was removed from their web at the same time points as the social treatment, but was immediately placed back on their own web. After repeatedly measuring adult behavior and web structure, we found that social rearing drove higher or significant levels of repeatability relative to the other treatments. Repeatability in the social treatment also decreased in some traits, paralleling the decreases observed in the disturbed treatments. Thus, repeated juvenile disturbance may decrease among-individual differences in adult spiders. Yet, social rearing appeared to override the effect of disturbance in some traits, suggesting a prioritization effect. The resulting individual differences were maintained over at least one-third of the adult lifespan and thus appear to represent stable, canalized developmental effects and not temporal state differences. These results provide proximate insight into how a broader range of developmental experiences shape trait variation.
发育可塑性已知会影响种群的平均行为表型。然而，关于发育可塑性如何塑造种群内变异模式的研究相对较少，且往往集中在一部分发育线索（如营养）上。一种潜在重要但未被充分研究的发育经历是社会经历，因为有明确假设认为它会增加个体间的变异，以此作为促进“社会生态位”的一种方式。为了验证这一点，我们通过每周一次将幼年黑寡妇蜘蛛移植到同种个体的网上48小时，直到成年，使其接触同种个体的蛛丝。我们还设置了一个未受触动的对照组以及一个受干扰组。后一组在与社会处理相同的时间点被从其网上移开，但立即被放回它们自己的网上。在反复测量成年个体的行为和蛛网结构后，我们发现与其他处理相比，社会饲养导致了更高或显著水平的重复性。社会处理中的重复性在一些性状上也有所下降，这与在受干扰处理中观察到的下降情况相似。因此，幼年时的反复干扰可能会减少成年蜘蛛个体间的差异。然而，社会饲养在某些性状上似乎抵消了干扰的影响，这表明存在一种优先效应。所产生的个体差异在成年期至少三分之一的时间内得以维持，因此似乎代表了稳定的、已形成的发育效应，而非暂时的状态差异。这些结果为更广泛的发育经历如何塑造性状变异提供了直接的见解。
