Data from: Towards 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.

广泛存在的生态位趋同现象表明，物种可依据功能性状（functional trait）组合进行归类，构建出类似元素周期表的分析框架。本研究针对蜥蜴类群收集生态数据，以探究全球及区域尺度的生态位分化模式，并通过多变量统计方法初步构建了生态位周期表。研究共收集了现存38个蜥蜴科中24科的134个物种的数据，涵盖5大类核心生态位维度：栖息地、食性、生活史、代谢与防御，共包含50余项变量。我们对生态位维度数据集开展主坐标分析（Principal Coordinates Analysis），并以前三个轴的物种得分作为输入，分别进行主成分分析（Principal Components Analysis）以在连续生态位空间中对物种进行排序，同时开展回归树分析（Regression Tree Analysis）以将物种划分为离散的生态位类别。三维模型可辅助探索物种在生态位超体积内与主要梯度的相对位置：第一轴梯度主要载荷于体型、觅食模式以及窝卵数；第二轴梯度受代谢水平以及陆生与树栖微生境的影响；第三轴梯度则受活动时间、生活史以及食性的影响。自然二分类别包括活动时间、觅食模式、繁殖方式以及栖息地。回归树分析共识别出103个支系（clade）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。将该研究方法拓展至其他类群，将有助于更全面地理解生态位演化机制。