Data from: The interplay of past diversification and evolutionary isolation with present imperilment across the amphibian tree of life

Human activities continue to erode the tree of life, requiring us to prioritize research and conservation. Amphibians represent key victims and bellwethers of global change, and the need for action to conserve them is drastically outpacing knowledge. We provide a phylogeny incorporating nearly all extant amphibians (7,238 species). Current amphibian diversity is composed of both older, depauperate lineages and extensive, more recent tropical radiations found in select clades. Frog and salamander diversification increased strongly after the Cretaceous–Palaeogene boundary, preceded by a potential mass-extinction event in salamanders. Diversification rates of subterranean caecilians varied little over time. Biogeographically, the Afro- and Neotropics harbour a particularly high proportion of Gondwanan relicts, comprising species with high evolutionary distinctiveness (ED). These high-ED species represent a large portion of the branches in the present tree: around 28% of all phylogenetic diversity comes from species in the top 10% of ED. The association between ED and imperilment is weak, but many species with high ED are now imperilled or lack formal threat status, suggesting opportunities for integrating evolutionary position and phylogenetic heritage in addressing the current extinction crisis. By providing a phylogenetic estimate for extant amphibians and identifying their threats and ED, we offer a preliminary basis for a quantitatively informed global approach to conserving the amphibian tree of life.

人类活动持续侵蚀生命之树，这要求我们将研究与保护工作置于优先地位。两栖动物既是全球变化的重要受害类群，也是全球环境变化的关键预警指示物种，当下保护两栖动物的行动需求已远超我们已掌握的相关认知。本研究构建了包含几乎所有现生两栖动物（共7238个物种）的系统发育树。当前两栖动物多样性既包含古老且物种贫乏的支系，也存在部分类群中新近出现的大规模热带适应辐射事件。蛙类与蝾螈的物种分化速率在白垩纪-古近纪界线后显著提升，而在此之前蝾螈类曾经历潜在的大规模灭绝事件；地下生活的蚓螈类物种分化速率则随时间变化极小。从生物地理学角度来看，非洲与新热带区拥有极高比例的冈瓦纳古陆孑遗物种，这类物种均具有较高的演化独特性（Evolutionary Distinctiveness，ED）。这类高ED物种占据了当前系统发育树中大量分支：全部系统发育多样性中约28%来自ED排名前10%的物种。尽管ED与物种受威胁程度之间的关联较弱，但诸多高ED物种目前正面临生存威胁，或是尚未被正式纳入濒危物种名录；这提示我们可通过整合物种演化地位与系统发育传承性，来应对当前的灭绝危机。本研究通过构建现生两栖动物的系统发育估算模型，并明确其受威胁状况与ED值，为采用量化依据制定全球两栖动物生命之树保护策略提供了初步基础。