Towards understanding the evolution of workforce organization in social spiders

点击翻译按钮获取中文摘要

Discussions of division of labor form the basis of much of the literate on social evolution in invertebrates. Division of Labor is a kind of workforce organization where individuals specialize on a subset of the maintenance tasks required for group function. High levels of individual task specialization are argued to be beneficial because specialists are predicted outperform generalists at their respective tasks, and groups composed of diverse sets of specialized individuals are predicted to outperform homogeneous groups. The benefits of division labor are likely best documented in the eusocial insects, however, the available data suggest division of labor can enhance the performance of non-eusocial groups and even pairs of individuals engaged in cooperative biparental care. In spite of its intuitive appeal, some researchers have argued that task specialization and enhanced division of labor might not always be favored, and that aspects of workforce organization like dynamic task switching may be more important determinants of social group success. This may be particularly true in environments where the demands imposed on colonies vary widely through time. Using six independently evolved lineages of social spiders from across the Anelosimus (New World) and Stegodyphus (Old World) genera, we propose to 1) characterize patterns of workforce organization in natural and experimental colonies, 2) test for associations between individuals' traits and their task performance profiles, 3) examine the degree to which between-group differences in workforce organization are linked to group success and how these relationships change based on the surrounding habitat (e.g., lowland rain forests vs. cloud forests), 4) probe how workforces change their patterns of task performance in response to shifts in ecological demands, and 5) scrutinize the role of self-organization in generating the patterns of workforce organization seen in social spiders. The proposed studies will critically evaluate the adaptive significance of division of labor versus other aspects of workforce organization in contrasting environments in a manner rarely achievable. For their part, these social spiders represent are extraordinarily tractable and well vetted system for conducting the proposed studies.