Data from: Delimiting species in recent radiations with low levels of morphological divergence: a case study in Australian Gehyra geckos

Recent conceptual and methodological advances have increased the ability to apply multifaceted approaches to species delimitation, which is particularly useful in delimiting recently diversified species where single lines of evidence lead to incorrect species delimitation or assignment of individuals to species (e.g. cryptic, morphological species and paraphyletic, hybridizing species). Species of the Australian Gehyra gecko radiation have historically proven difficult to delimit due the group’s uniform, almost continent-wide geographic distribution and conservative morphology, contrasting high chromosomal and genetic diversity. Using an integrated approach to species delimitation taking advantage of morphological, geographic distributional and multi-locus genetic data, we investigate the diversity within three Gehyra species from the Australian arid zone. Our results show that these species represent eight distinct phylogenetic lineages, which display different patterns of morphological distinction and reproductive isolation. Using a recently developed Bayesian species delimitation method, we also find different levels of support for putative species dependent on priors for population size and timing of diversification assumed. Our results show that the current taxonomy does not adequately account for the diversity of the group. Discrepancies between lines of evidence indicate that diversification of the group is recent and ongoing, thus posing challenges for both species concepts and delimitation.近年来，概念与方法层面的进展提升了我们运用多维度方法开展物种界定（species delimitation）的能力，该手段在界定近期分化类群时尤为实用——当单一证据链会导致错误的物种界定或个体物种归属时（如隐存物种、形态保守物种，以及并系、杂交类群），其优势尤为凸显。澳大利亚异趾虎属（Gehyra）辐射演化类群的物种界定长期以来颇具难度：该类群形态保守，地理分布近乎覆盖整个澳洲大陆且均一性强，但却伴随极高的染色体与遗传多样性，二者形成鲜明反差。本研究整合形态学、地理分布及多位点遗传数据构建物种界定框架，对澳大利亚干旱区3个异趾虎属物种的多样性展开探究。研究结果显示，这3个物种实则包含8个独立的系统发育支系，各支系在形态分化与生殖隔离模式上均存在差异。本研究借助新近开发的贝叶斯物种界定方法，还发现：基于不同的种群大小先验参数与分化时间假设，推定物种的支持度存在显著差异。研究结果表明，当前的分类学体系未能充分反映该类群的真实多样性。不同证据链间的不一致性显示，该类群的分化过程仍处于近期且仍在进行的状态，这给物种概念界定与物种划分工作均带来了挑战。