Data from: What explains patterns of diversification and richness among animal phyla?

Animal phyla vary dramatically in species richness (from one species to >1.2 million), but the causes of this variation remain largely unknown. Animals have also evolved striking variation in morphology and ecology, including sessile marine taxa lacking heads, eyes, limbs, and complex organs (e.g., sponges), parasitic worms (e.g., nematodes, platyhelminths), and taxa with eyes, skeletons, limbs, and complex organs that dominate terrestrial ecosystems (arthropods, chordates). Relating this remarkable variation in traits to the diversification and richness of animal phyla is a fundamental yet unresolved problem in biology. Here, we test the impacts of 18 traits (including morphology, ecology, reproduction, and development) on diversification and richness of extant animal phyla. Using phylogenetic multiple regression, the best-fitting model includes five traits that explain ∼74% of the variation in diversification rates (dioecy, parasitism, eyes/photoreceptors, a skeleton, nonmarine habitat). However, a model including just three (skeleton, parasitism, habitat) explains nearly as much variation (∼67%). Diversification rates then largely explain richness patterns. Our results also identify many striking traits that have surprisingly little impact on diversification (e.g., head, limbs, and complex circulatory and digestive systems). Overall, our results reveal the key factors that shape large-scale patterns of diversification and richness across >80% of all extant, described species.动物门类（Animal phyla）的物种丰富度（species richness）差异悬殊，从单物种至超120万种不等，但造成这种差异的原因在很大程度上仍未明确。动物在形态学与生态学特征上演化出显著变异：包括无头部、眼睛、附肢及复杂器官的固着生活海洋类群，例如海绵动物门（sponges）、寄生蠕虫类群，例如线虫动物门（nematodes）、扁形动物门（platyhelminths），以及拥有眼睛、骨骼、附肢与复杂器官、占据陆地生态系统主导地位的类群，例如节肢动物门（arthropods）、脊索动物门（chordates）。将这些性状的显著变异与动物门类的多样化（diversification）过程与物种丰富度建立关联，是生物学领域一项基础却尚未解决的核心问题。本研究针对18项性状（涵盖形态学、生态学、繁殖与发育维度），检验其对现生（extant）动物门类的多样化速率与物种丰富度的影响。通过系统发育多重回归分析，最优拟合模型包含5项性状，可解释约74%的多样化速率变异：雌雄异体（dioecy）、寄生生活（parasitism）、眼睛/光感受器（eyes/photoreceptors）、骨骼结构（skeleton）、非海洋生境（nonmarine habitat）。然而仅包含3项性状（骨骼结构、寄生生活、生境类型）的模型，亦可解释近67%的变异，解释力与之相差无几。多样化速率可在很大程度上解释物种丰富度的分布格局。本研究结果还发现，诸多性状对多样化速率的影响出人意料地微弱，例如头部、附肢以及复杂循环与消化系统等。整体而言，本研究结果揭示了塑造全球超80%的现生已描述物种的大规模多样化速率与物种丰富度格局的核心驱动因素。