Data from: Unpacking the extinction crisis: rates, patterns, and causes of recent extinctions in plants and animals

Biodiversity loss is considered one of the greatest challenges facing Earth today. The most direct information on species loss comes from the hundreds of human-related extinctions in the recent past. However, our understanding of these recent extinctions is incomplete, especially in terms of their causes and their rates and patterns among clades, across habitats, and over time. Furthermore, prominent studies have extrapolated these extinctions to suggest that Earth is experiencing a mass extinction event. Such extrapolations assume that recent extinctions predict current extinction risk and are homogeneous among groups, over time, and among environments. Here, we analyze rates and patterns of recent extinctions (last ~500 years). Surprisingly, we find that past extinctions did not strongly predict current risk among groups. Extinctions varied strongly among groups, and were most frequent among mollusks, turtles, birds, and mammals, and relatively rare in plants and the largest group of animals (arthropods). Extinction rates varied over time, increasing over the last five centuries, but (surprisingly) often declining in the last ~100 years. Recent extinctions were biased ecologically, with high frequencies in freshwater and on islands (and with most non-island extinctions in freshwater). Island extinctions were caused most frequently by invasive species, but habitat loss was the most important cause and current threat in continental regions. Overall, we identify the major patterns in recent extinctions. We also suggest that past extinctions should not be extrapolated without accounting for how they vary among groups, among habitats, and over time.

生物多样性丧失被视为当今地球面临的最严峻挑战之一。我们获取物种丧失相关直接信息的最主要来源，是近期数百起与人类活动相关的物种灭绝事件。然而，我们对这些近期灭绝事件的认知仍存在诸多不足，尤其是在其成因、各演化支（clade）间的灭绝速率与模式、不同生境下的差异以及随时间的变化规律等方面。此外，部分权威研究通过对这些灭绝事件进行外推，得出地球正经历大规模灭绝事件的结论。这类外推研究均基于两项假设：一是近期灭绝事件可用于预测当前的物种灭绝风险，二是不同类群、不同时期以及不同环境下的灭绝模式均无差异。本研究针对近约500年来的物种灭绝事件的速率与模式展开分析。令人意外的是，研究发现，过往的灭绝事件并不能有效预测不同类群当前的灭绝风险。不同类群的灭绝频率差异显著：软体动物、龟类、鸟类与哺乳类的灭绝事件最为频发，而植物以及动物界最大的类群——节肢动物（arthropod）的灭绝事件则相对稀少。灭绝速率随时间呈现明显波动：在过去五个世纪中整体呈上升趋势，但令人意外的是，近约100年来却往往呈下降态势。近期灭绝事件在生态层面存在明显偏向：淡水生态系统与岛屿环境中的物种灭绝频率极高（且多数非岛屿灭绝事件均发生于淡水环境中）。岛屿物种灭绝的最常见诱因为外来物种入侵，而在大陆区域，栖息地丧失则是最为关键的致因与当前威胁。综上，本研究明确了近期物种灭绝事件的主要模式，并提出：在未考虑不同类群、不同生境以及不同时期的灭绝差异的前提下，不应直接通过过往灭绝事件进行外推分析。