Abstract:
Barking geckos (genus Ptenopus) are terrestrial, burrowing lizards endemic to southern Africa, currently with three recognised species. Two species are range-restricted (P. kochi and P. carpi) and display clear differences in substrate preference (soft sand vs. hard gravel). The third and most widespread species, P. garrulus, occurs on a variety of substrates of differing hardness, across potential geographic barriers, and over a steep climatic gradient. Variations in morphology and advertisement calls indicates that P. garrulus may be a species complex. Two subspecies of P. garrulus are currently recognised: P. g. maculatus and P. g. garrulus. To investigate species boundaries, we produced the first comprehensive phylogeny for the genus. We used a novel application of multiple regression on matrices models to assess multiple environmental drivers of diversification, as contrasted to isolation by distance. We show that P. kochi, P. carpi, and P. g. garrulus are valid species, but that P. g. maculatus is a paraphyletic complex of five previously unrecognised taxa. Specialisation onto different substrates was likely the main driver of divergence, with parapatric occurrence of two to four clades occurring at each of the three substrate transition zones identified a priori. The region encompasses diverse bioclimatic regions and potential geographic barriers, and these likely played a role in some divergence events.
摘要:
吠叫壁虎(Ptenopus属)是陆生的,南非特有的挖洞蜥蜴,目前有三个公认的物种。有两个物种受到范围限制(P.kochi和P.carpi),并显示出明显的底物偏好差异(软砂与硬砾石)。第三个也是最广泛的物种,P.Garrulus,发生在各种不同硬度的基材上,跨越潜在的地理障碍,和陡峭的气候梯度。形态和广告调用的变化表明P.garrulus可能是一个物种复合体。目前认识到P.garrulus的两个亚种:P.g.maculatus和P.g.garrulus。为了调查物种边界,我们为该属产生了第一个全面的系统发育。我们在矩阵模型上使用多元回归的新应用来评估多元化的多个环境驱动因素,与距离隔离形成对比。我们证明了P.kochi,P.Carpi,P.G.Garrulus是有效的物种,但是P.g.maculatus是五个以前未被识别的分类群的共生复合体。对不同底物的专业化可能是分歧的主要驱动因素,在先验确定的三个底物过渡区域中的每个区域都发生了两到四个分支。该区域包括不同的生物气候区域和潜在的地理障碍,这些可能在一些分歧事件中发挥作用。