Foley Nicole M, Springer Mark S, Teeling Emma C
School of Biology and Environmental Science, Science Centre East, University College Dublin, Dublin 4, Ireland.
Department of Biology, University of California, Riverside, CA 92521, USA
Philos Trans R Soc Lond B Biol Sci. 2016 Jul 19;371(1699). doi: 10.1098/rstb.2015.0140.
Most molecular phylogenetic studies place all placental mammals into four superordinal groups, Laurasiatheria (e.g. dogs, bats, whales), Euarchontoglires (e.g. humans, rodents, colugos), Xenarthra (e.g. armadillos, anteaters) and Afrotheria (e.g. elephants, sea cows, tenrecs), and estimate that these clades last shared a common ancestor 90-110 million years ago. This phylogeny has provided a framework for numerous functional and comparative studies. Despite the high level of congruence among most molecular studies, questions still remain regarding the position and divergence time of the root of placental mammals, and certain 'hard nodes' such as the Laurasiatheria polytomy and Paenungulata that seem impossible to resolve. Here, we explore recent consensus and conflict among mammalian phylogenetic studies and explore the reasons for the remaining conflicts. The question of whether the mammal tree of life is or can be ever resolved is also addressed.This article is part of the themed issue 'Dating species divergences using rocks and clocks'.
劳亚兽总目（如狗、蝙蝠、鲸鱼）、灵长总目（如人类、啮齿动物、鼯猴）、异关节总目（如犰狳、食蚁兽）和非洲兽总目（如大象、海牛、刺猬），并估计这些进化枝最后一个共同祖先生活在9000万至1.1亿年前。这种系统发育为众多功能和比较研究提供了一个框架。尽管大多数分子研究之间的一致性程度很高，但关于胎盘哺乳动物根部的位置和分歧时间，以及某些似乎无法解决的“硬节点”，如劳亚兽总目的多分支和蹄兔目，仍然存在问题。在这里，我们探讨了哺乳动物系统发育研究中最近的共识和冲突，并探讨了剩余冲突的原因。本文还讨论了哺乳动物生命树是否能够或能否得到解决的问题。本文是主题为“利用岩石和时钟确定物种分歧时间”的特刊的一部分。
