Jennings W Bryan
Department of Evolution, Ecology, & Organismal Biology, University of California, Riverside, Riverside, California, United States of America.
Departamento de Vertebrados, Museu Nacional, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.
PeerJ. 2021 Jun 29;9:e11502. doi: 10.7717/peerj.11502. eCollection 2021.
Here, I review phylogenetic studies of the lizard family Pygopodidae, a group of 47 extant species that diversified in Australia and New Guinea. The goal of this study was to examine published phylogenetic and phylogenomic hypotheses on pygopodids to identify the strengths and weaknesses in our understanding of their phylogeny. Many parts of the pygopodid family tree are well established by multiple independent tree inferences including: (1) all multispecies genera (i.e., , , , , and ) are monophyletic groups; (2) the root of the pygopodid tree is located along the branch leading to the clade, thus showing that is the sister group to all other pygopodid genera; (3) the group, group, and several other groups of closely related species are demonstrated to be monophyletic entities; and (4) the monotypic is the sister lineage to the clade. Based on accumulated phylogenetic evidence, two taxonomic recommendations are given: merits generic status rather than being subsumed into as some earlier studies had suggested, and the monotypic should be recognized as a member of (following current practice) until future studies clarify its placement inside or outside the clade. One chronic problem with phylogenetic studies of pygopodids, which has limited the explanatory power of many tree hypotheses, concerns the undersampling of known species. Although the continual addition of newly described species, especially over the past two decades, has been a major reason for these taxon sampling gaps, deficits in species sampling for ingroups and/or outgroups in several studies of pygopodid species complexes has confounded the testing of some ingroup monophyly hypotheses. Ancient hybridization between non-sister lineages may also be confounding attempts to recover the relationships among pygopodids using molecular data. Indeed, such a phenomenon can explain at least five cases of mito-nuclear discordance and conflicts among trees based on nuclear DNA datasets. Another problem has been the lack of consensus on the relationships among most pygopodid genera, an issue that may stem from rapid diversification of these lineages early in the group's history. Despite current weaknesses in our understanding of pygopodid phylogeny, enough evidence exists to clarify many major and minor structural parts of their family tree. Accordingly, a composite tree for the Pygopodidae was able to be synthesized. This novel tree hypothesis contains all recognized pygopodid species and reveals that about half of the clades are corroborated by multiple independent tree hypotheses, while the remaining clades have less empirical support.
在此，我回顾了鳞脚蜥科的系统发育研究，该科有47个现存物种，在澳大利亚和新几内亚地区实现了多样化。本研究的目的是审视已发表的关于鳞脚蜥科的系统发育和系统基因组学假说，以确定我们对其系统发育理解中的优势与不足。鳞脚蜥科的家族树的许多部分已通过多个独立的树推断得到很好的确立，包括：（1）所有多物种属（即 、 、 、 和 ）都是单系类群；（2）鳞脚蜥科树的根部位于通向 进化枝的分支上，这表明 是所有其他鳞脚蜥科属的姐妹群；（3） 组、 组以及其他几个密切相关物种的组被证明是单系实体；（4）单型的 是 进化枝的姐妹谱系。基于积累的系统发育证据，给出了两条分类学建议： 应具有属的地位，而不是像一些早期研究所建议的那样归入 属，并且单型的 在未来研究明确其在 进化枝内部或外部的位置之前，应被视为 的一个成员（按照当前的做法）。鳞脚蜥科系统发育研究的一个长期问题限制了许多树假说的解释力，这个问题是已知物种采样不足。尽管不断增加新描述的物种，特别是在过去二十年中，是这些分类单元采样差距的主要原因，但在一些鳞脚蜥科物种复合体的研究中，内群和/或外群的物种采样不足混淆了一些内群单系性假说的检验。非姐妹谱系之间的古老杂交也可能使利用分子数据恢复鳞脚蜥科之间关系的尝试变得复杂。事实上，这种现象至少可以解释基于核DNA数据集的线粒体 - 核不一致以及树之间冲突的五个案例。另一个问题是对于大多数鳞脚蜥科属之间的关系缺乏共识，这个问题可能源于这些谱系在该类群历史早期的快速多样化。尽管目前我们对鳞脚蜥科系统发育的理解存在不足，但有足够的证据来阐明其家族树的许多主要和次要结构部分。因此，能够合成一个鳞脚蜥科的综合树。这个新的树假说包含了所有已识别的鳞脚蜥科物种，并表明大约一半的进化枝得到了多个独立树假说的支持，而其余的进化枝得到的实证支持较少。
