Jiménez F Agustín, Gardner Scott L, Navone Graciela, Ortí Guillermo
Department of Zoology, Southern Illinois University, Carbondale, Illinois 62901-6501, USA.
J Parasitol. 2012 Dec;98(6):1166-75. doi: 10.1645/GE-3045.1. Epub 2012 Jun 4.
The Great American Interchange resulted in the mixing of faunistic groups with different origins and evolutionary trajectories that underwent rapid diversification in North and South America. As a result, groups of animals of recent arrival converged into similar habits and formed ecological guilds with some of the endemics. We present a reconstruction of the evolutionary events in Aspidoderidae, a family of nematodes that infect mammals that are part of this interchange, i.e., dasypodids, opossums, and sigmodontine, geomyid, and hystricognath rodents. By treating hosts as discrete states of character and using parsimony and Bayesian inferences to optimize these traits into the phylogeny of Aspidoderidae, we reconstructed Dasypodidae (armadillos) as the synapomorphic host for the family. In addition, 4 events of host switching were detected. One consisted of the switch from dasypodids to hystricognath rodents, and subsequently to geomyid rodents. The remaining set of events consisted of a switch from dasypodids to didelphid marsupials and then to sigmodontine rodents. The reconstruction of the ancestral distribution suggests 3 events of dispersal into the Nearctic. Two of these invasions would suggest that 2 different lineages of dasypodid parasites entered the Northern Hemisphere at different times, which is consistent with the presence of 2 lineages of armadillos in Mexico.
大美洲生物交流导致了具有不同起源和进化轨迹的动物区系混合，这些动物区系在南北美洲经历了快速分化。结果，新近到达的动物群体形成了相似的习性，并与一些本地物种组成了生态群落。我们展示了对隐尾线虫科进化事件的重建，该线虫科感染哺乳动物，而这些哺乳动物是这次生物交流的一部分，即犰狳科动物、负鼠以及稻鼠亚科、囊鼠科和豪猪亚目啮齿动物。通过将宿主视为性状的离散状态，并使用简约法和贝叶斯推断将这些性状优化到隐尾线虫科的系统发育中，我们将犰狳科（犰狳）重建为该科的共衍征宿主。此外，还检测到4次宿主转换事件。一次是从犰狳科动物转换到豪猪亚目啮齿动物，随后又转换到囊鼠科啮齿动物。其余的事件包括从犰狳科动物转换到袋鼬科有袋动物，然后再转换到稻鼠亚科啮齿动物。祖先分布的重建表明有3次扩散到新北界的事件。其中两次入侵表明犰狳科寄生虫的两个不同谱系在不同时间进入北半球，这与墨西哥存在两种犰狳谱系的情况一致。
