Data from: Toward a periodic table of niches, or exploring the lizard niche hypervolume

Widespread niche convergence suggests that species can be organized according to functional trait combinations to create a framework analogous to a periodic table. We compiled ecological data for lizards to examine patterns of global and regional niche diversification, and used multivariate statistical approaches to develop the beginnings for a periodic table of niches. Data (50+ variables) for five major niche dimensions (habitat, diet, life history, metabolism, defense) were compiled for 134 species of lizards representing 24 of the 38 extant families. Principal Coordinates Analyses were performed on niche dimensional datasets, and species scores for the first three axes were used as input for a Principal Components Analysis to ordinate species in continuous niche space, and for a Regression Tree Analysis to separate species into discrete niche categories. 3D models facilitate exploration of species positions in relation to major gradients within the niche hypervolume. The first gradient loads on body size, foraging mode, and clutch size. The second was influenced by metabolism and terrestrial versus arboreal microhabitat. The third was influenced by activity time, life history, and diet. Natural dichotomies are activity time, foraging mode, parity mode, and habitat. Regression tree analysis identified 103 cases of extreme niche conservatism within clades and 100 convergences between clades. Extending this approach to other taxa should lead to a wider understanding of niche evolution.

广泛存在的生态位（niche）趋同现象表明，物种可依据功能性状组合进行归类，从而构建出类似元素周期表的分类框架。本研究针对蜥蜴收集生态数据，以探究全球及区域尺度的生态位分化格局，并通过多变量统计方法初步构建了生态位周期表。本研究针对现存38个蜥蜴科中的24个科的134个蜥蜴物种，收集了涵盖5大生态位维度（生境、食性、生活史、代谢、防御）的共50余项变量数据。研究人员对生态位维度数据集开展主坐标分析（Principal Coordinates Analyses），并将前三个轴的物种得分作为输入，分别用于主成分分析（Principal Components Analysis）以在连续生态位空间中对物种进行排序，以及回归树分析（Regression Tree Analysis）以将物种划分为离散的生态位类别。三维模型可帮助研究者探索物种在生态位超体积内沿主要梯度的分布位置。第一梯度主要关联体型大小、觅食模式与窝卵数。第二梯度受代谢特征以及陆生与树栖微生境的影响。第三梯度则与活动时长、生活史及食性相关。自然二分类别包括活动时长、觅食模式、繁殖模式与生境类型。回归树分析共识别出103个支系（clades）内极端生态位保守的案例，以及100个支系间的生态位趋同案例。将该研究方法推广至其他类群（taxa），将有助于更全面地理解生态位演化的内在机制。