REU: Dance Language, Eusociality, and the Systematics of Apis and the Apidae

蜜蜂表现出两种复杂的社会行为，长期以来一直吸引着人类观察者：一种是“舞蹈语言”，这是一系列身体动作，通过这些动作，成功的侦察蜜蜂可以精确地将10公里外花朵的位置传达给它们的巢穴同伴；以及高度组织化的多年生殖民地。我们今天在蜜蜂身上看到的行为是如何从它们独居的祖先的简单能力演变而来的，我们对此知之甚少。与结构不同，行为不是一成不变的，因此不能直接观察到变化的历史顺序。相反，它必须从密切相关的现存物种的比较中推断出来。由于相关物种的相同特征可以被认为是来自一个共同的祖先，人们可以从现存物种之间的相似和差异中推断出祖先特征的特征，以及在下降过程中发生的变化。有6-8种蜜蜂（Apis属），它们都有舞蹈语言，但在舞蹈的细节上有所不同。所有的Apis物种都有先进的社会，但其他属的蜜蜂表现出不同程度的社会组织。这些模式已经被用来形成关于这些行为进化的竞争性假设。由于没有一组独立的性状能令人满意地解决蜜蜂物种之间和不同蜂属之间的系统发育关系，因此仍然存在歧义。目前的项目将首次对蜜蜂的分子变异进行全面研究，尽管对所有物种中发现的一个基因的核苷酸（DNA分子的亚基）序列进行了分析。将在亚洲和中美洲的几个地点收集标本，提取基因并进行测序，并根据序列的变化确定物种之间的系统发育关系。与此同时，将进行进一步的详细研究，以更清楚地了解物种之间的行为变化模式。把这些方法结合起来，应该会对两个问题给出更令人满意的答案：舞蹈是如何从一系列更简单的行为中组合起来的，以及高级社会性是只起源于蜜蜂，还是起源于一个祖先，后者也产生了其他高度社会性的蜜蜂。除了让我们更好地了解这一迷人的、具有重要生态意义的生物群体的生物学外，该项目还将为结合分子和行为方法来重建其他动物复杂行为的进化提供一个模型。此外，东南亚不同蜜蜂种群之间的变异模式可能有助于深入了解动物种群在孤立进化过程中行为和遗传差异的控制过程，这些蜜蜂种群被分散成不同距离和不同时期的岛屿。最后，鉴于蜜蜂在热带森林树木授粉中所起的突出作用，这些研究可以帮助未来尝试了解这一重要生态系统的生态学。

Honey bees exhibit two complex social behaviors which have long fascinated human observers: the "dance language," a series of body movements whereby successful scout bees precisely communicate to their nestmates the locations of flowers as far away as 10 kilometers; and highly organized, perennial colonies. Little is known about how the behaviors we see in honey bees alive today emerged from the simpler capabilities of their solitary-living ancestors. Since behavior, unlike structure, is not fossilized, the historical sequences of changes cannot be observed directly. Instead, it must be inferred from comparisons of closely related living species. Since equivalent traits in related species can be assumed to have descended from a common ancestor, one can infer the characteristics of the ancestral trait, and the modifications that occurred during descent, from the similarities and differences seen among species now alive. There are 6-8 species of honey bees (genus Apis which all have dance languages, but which differ in the details of the dances. All the Apis species have advanced societies, but bees in other genera exhibit varying degrees of social organization. These patterns have already been used to formulate competing hypotheses about the evolution of these behaviors. Ambiguities remain because no set of independent traits has satisfactorily resolved the phylogenetic relationships among the honey bee species, and among the different bee genera. The present project will undertake the first comprehensive study of molecular variation among bees, though an analysis of sequences of nucleotides (subunits of the DNA molecule) in a gene found in all the species. Specimens will be collected in several locations in Asia and Central America, the gene extracted and sequenced, and the phylogenetic relationships among the species determined from variations in the sequences. At the same time, further detailed studies will be done to obtain a clearer picture of the pattern of behavioral variation among the species. Together these approaches should lead to more satisfying answers to two questions: how the dance was assembled from a set of simpler behaviors, and whether advanced sociality originated uniquely in honey bees or was derived from an ancestor which also gave rise to other highly social bees. Apart from leading to a better understanding of the biology of a fascinating and ecologically important group of organisms, this project will also provide a model for combining molecular and behavioral approaches to reconstruct the evolution of complex behavior in other animals. Additionally, the patterns of variation among different honey bee populations in Southeast Asia, which is fragmented into islands separated by a range of distances and for varying periods of time, could lead to insights into the processes governing the behavioral and genetic divergence of animal populations evolving in isolation. Finally, given the prominent role played by the honey bees in the pollination of trees in tropical forests, these studies could aid future attempts to understand the ecology of this important ecosystem.