榕树–榕小蜂互惠合作系统中的非对称性博弈

Asymmetric interactions in fig–fig wasp mutualism

榕树及其传粉榕小蜂是自然界中目前所知道的关系最为紧密的互利共生系统之一。随着研究的深入,越来越多的证据发现榕树–传粉榕小蜂之间互惠合作的过程中存在着复杂的竞争和对抗关系,例如榕树与传粉榕小蜂之间对公共资源的竞争、传粉欺骗与宿主对传粉者的惩罚、榕树与传粉小蜂之间的"军备竞赛"等。在相互竞争或者对抗关系中,双方表现出非对称性相互作用。其非对称性关系主要表现出如下3个特征:(1)收益不对称,即榕树(宿主)与传粉榕小蜂(共生体)之间在资源利用等方面的实力不对称;(2)榕树与传粉榕小蜂之间的信息不对称;(3)进化速率不对称。这些非对称的相互作用可能导致种群的波动、榕树与传粉榕小蜂相互适应和进化策略的变化。因此,理解榕树与传粉榕小蜂之间的非对称交互作用有助于理解为什么合作和冲突在互利共生关系中经常能同时存在,也将有助于解释榕树–传粉榕小蜂种间相互关系和物种的多样性。

Fig and fig pollinating wasps constitute one of the most well-known systems of mutualistic interactions between species. However, interspecific competition and antagonism is increasingly observed in this obligate mutualism system, including competition over common resources, pollination cheating and host sanction, and an evolutionary arms race between the host tree and its pollinators. In the competitive and antagonistic interactions between fig and fig pollinating wasps, three main asymmetric relationships have been identified:(1) asymmetric payoffs, i.e., asymmetric power between figs(host) and their pollinators(symbionts);(2) asymmetric rates of evolution;and(3) asymmetric information between figs and their pollinators. The asymmetric relationships may affect population dynamics and the mutual adaptation and evolutionary strategies of each species, which helps explain why both cooperation and conflict are simultaneously observed within a specific mutualism, and why diversified strategies and species coexistence are found in nearly all mutualism systems.