Science and Solutions for a Changing Planet DTP, and the Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, Berkshire, United Kingdom.
EDGE of Existence Programme, Zoological Society of London, Regent's Park, London, United Kingdom.
PLoS One. 2018 Apr 11;13(4):e0194680. doi: 10.1371/journal.pone.0194680. eCollection 2018.
The scale of the ongoing biodiversity crisis requires both effective conservation prioritisation and urgent action. As extinction is non-random across the tree of life, it is important to prioritise threatened species which represent large amounts of evolutionary history. The EDGE metric prioritises species based on their Evolutionary Distinctiveness (ED), which measures the relative contribution of a species to the total evolutionary history of their taxonomic group, and Global Endangerment (GE), or extinction risk. EDGE prioritisations rely on adequate phylogenetic and extinction risk data to generate meaningful priorities for conservation. However, comprehensive phylogenetic trees of large taxonomic groups are extremely rare and, even when available, become quickly out-of-date due to the rapid rate of species descriptions and taxonomic revisions. Thus, it is important that conservationists can use the available data to incorporate evolutionary history into conservation prioritisation. We compared published and new methods to estimate missing ED scores for species absent from a phylogenetic tree whilst simultaneously correcting the ED scores of their close taxonomic relatives. We found that following artificial removal of species from a phylogenetic tree, the new method provided the closest estimates of their "true" ED score, differing from the true ED score by an average of less than 1%, compared to the 31% and 38% difference of the previous methods. The previous methods also substantially under- and over-estimated scores as more species were artificially removed from a phylogenetic tree. We therefore used the new method to estimate ED scores for all tetrapods. From these scores we updated EDGE prioritisation rankings for all tetrapod species with IUCN Red List assessments, including the first EDGE prioritisation for reptiles. Further, we identified criteria to identify robust priority species in an effort to further inform conservation action whilst limiting uncertainty and anticipating future phylogenetic advances.
当前生物多样性危机的规模要求采取有效的保护优先级排序和紧急行动。由于灭绝在生命之树上是随机发生的，因此重要的是要优先考虑代表大量进化历史的受威胁物种。EDGE 指标根据物种的进化独特性（ED）和全球濒危程度（GE）或灭绝风险对物种进行优先级排序。ED 指标通过衡量物种对其分类群总进化历史的相对贡献来衡量物种的进化独特性。EDGE 指标的优先级排序依赖于足够的系统发育和灭绝风险数据，以生成有意义的保护优先级排序。然而，大型分类群的综合系统发育树极为罕见，即使可用，由于物种描述和分类修订的快速速度，也会很快过时。因此，保护主义者能够利用可用数据将进化历史纳入保护优先级排序是很重要的。我们比较了发表的和新的方法，以估计在没有系统发育树的情况下物种的缺失 ED 得分，同时纠正其近亲的 ED 得分。我们发现，在从系统发育树中人工删除物种后，新方法提供了最接近的“真实”ED 得分估计值，与真实 ED 得分的差异平均不到 1%，而前两种方法的差异分别为 31%和 38%。随着从系统发育树中人工删除的物种越来越多，前两种方法也大大低估和高估了得分。因此，我们使用新方法估计了所有四足动物的 ED 得分。根据这些得分，我们更新了具有 IUCN 红色名录评估的所有四足动物的 EDGE 优先级排序，包括对爬行动物的第一次 EDGE 优先级排序。此外，我们确定了识别稳健优先物种的标准，以进一步为保护行动提供信息，同时限制不确定性并预测未来的系统发育进展。
