Moore Wendy, Robertson James A
Department of Entomology, University of Arizona, Tucson, AZ 85721-0036, USA.
Department of Entomology, University of Arizona, Tucson, AZ 85721-0036, USA.
Curr Biol. 2014 Oct 20;24(20):2435-9. doi: 10.1016/j.cub.2014.09.022. Epub 2014 Oct 2.
Ant-nest beetles (Paussus) are the quintessential Trojan horses of the insect world. They hack the complex communication system of ants, allowing them to blend into the ant society and be treated as royalty, all the while preying upon the ants and the ants' brood and duping the ants into rearing their young. Here we present results of the first molecular-based phylogeny of ant-nest beetles, which reveals that this symbiosis has produced one of the most stunning examples of rapid adaptive radiation documented to date. The most recent ancestor of a Paussus clade endemic to Madagascar is only 2.6 million years old. This species gave rise to a remarkably phenotypically diverse clade of 86 extant species with a net diversification interval of 0.38-0.81 million years, a rate of radiation faster than classic textbook examples of large, recent, rapid radiations such as Anolis lizards on Caribbean islands, cichlids of the East African Great Lakes, finches on the Galápagos Islands, and Drosophila and tetragnathid spiders on the Hawaiian Islands. In order for Paussus to adapt to a new host ant species, the beetle's ability to perceive, deceive, and communicate with the new host must evolve quickly and in synchrony in both the larval and adult life stages, resulting in unusually strong selective pressure levied by their host ants. Data on host associations suggest that the history of host shifts may help explain both the striking phenotypic diversity within the Malagasy radiation and the evolution of phenotypically similar yet distantly related species in Madagascar and Africa.
蚁巢甲虫（Paussus属）是昆虫世界中典型的特洛伊木马。它们破解了蚂蚁复杂的通讯系统，使自己能够融入蚁群并被当作蚁王对待，与此同时捕食蚂蚁及其幼虫，并欺骗蚂蚁抚养自己的后代。在此，我们展示了首个基于分子的蚁巢甲虫系统发育研究结果，该结果表明这种共生关系造就了迄今为止有记录的最惊人的快速适应性辐射案例之一。马达加斯加特有的一个Paussus分支的最近共同祖先仅有260万年历史。这个物种演化出了一个包含86个现存物种的极为表型多样的分支，其净多样化间隔为38万至81万年，辐射速率比一些经典教科书例子中的近期大型快速辐射更快，比如加勒比岛屿上的安乐蜥、东非大湖中的丽鱼科鱼、加拉帕戈斯群岛上的雀类，以及夏威夷群岛上的果蝇和长脚蛛。为了适应新的宿主蚂蚁物种，这种甲虫感知、欺骗新宿主以及与之交流的能力必须在幼虫和成虫阶段都快速且同步地进化，这导致宿主蚂蚁施加了异常强大的选择压力。关于宿主关联的数据表明，宿主转移的历史可能有助于解释马达加斯加辐射中显著的表型多样性，以及马达加斯加和非洲表型相似但亲缘关系较远的物种的进化。
