Mathematical Sciences: Collaborative Research on CooperationAmong Animals: Mutualism Versus Reciprocity

研究人员使用进化博弈论来研究动物之间的合作行为。他们致力于建立一个一般性理论，将自然界中的合作行为分为亲缘选择行为、群体选择行为、副产品互惠主义或互惠利他主义。为了实现这一目标，他们的研究重点是可以先验地排除在上述前两类之外的合作行为。这种行为的例子是乌鸦的食物分享和狮子的防御行为。因此，研究人员将重点放在互惠与互惠上，并建立了一个数学模型来区分这两类合作行为。这个模型很重要，因为自然界中互惠的许多例子都是假设的，但几乎没有一个得到证明：如果没有这样一个模型，实际上每个例子都可以同样地被解释为互惠的例子。这项研究的目的是确定动物在自然界中是否能够合作，因为它们对特定个体所做的和所得到的帮助进行记分，或者因为它们的长期自身利益的行为与它们的社区的最佳利益的行为是一致的，即使它们不记分。从纯科学的角度来看，这个问题的答案将大大推进目前对动物行为的认识。从更实用的角度来看，尽管这项研究的主要对象是野外的非人类动物，但研究人员的发现也将与实现人类之间的合作有关。特别是，这项研究的结果可能有助于解决公地的紧迫问题，即为全球环境的可持续管理设计合作性社会结构的问题。

Mesterton-Gibbons 9626609 The investigators use evolutionary game theory to study cooperative behavior among animals. They work toward a general theory that categorizes cooperative behavior in nature as kin-selected behavior, group-selected behavior, byproduct mutualism, or reciprocal altruism. In pursuit of this goal, their investigation focuses on cooperative behaviors that can be excluded on a priori grounds from the first two categories mentioned above. Examples of such behaviors are food sharing in ravens and defensive behavior in lions. Accordingly, the investigators focus on reciprocity versus mutualism and develop a mathematical model with the power to discriminate between these two categories of cooperative behavior. The model is important because many examples of reciprocity in nature have been hypothesized, but hardly any have been proven: without such a model, virtually every example is equally interpretable as a case of mutualism. The goal of the study is to determine whether animals can cooperate in nature because they keep score of favors done to -- and favors received from -- specific individuals, or because acting in their long-term self-interest coincides with acting in the best interest of their community, even though they do not keep score. From a purely scientific perspective, an answer to this question will advance current knowledge of animal behavior considerably. From a more utilitarian perspective, even though the study's primary subjects are non-human animals in the wild, the investigators' findings will be relevant to achieving cooperation among humans as well. In particular, the study's findings may help to solve the urgent problem of the commons, i.e., the problem of designing cooperative social structures for sustainable management of the global environment.