Comprehensive support for diversity in STEM
Comprehensive support for diversity in STEM
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对 STEM 多样性的全面支持
DOI：
10.1126/science.add8056
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发表时间：
2022
期刊：
影响因子：
56.9
通讯作者：
Middendorf, George
中科院分区：
文献类型：
--
作者：
Mourad, Teresa;Middendorf, George
两栖动物的特点是新物种的发现和物种的下降率最高的脊椎动物在世界各地（1）。为了更快地描述这种多样性，动物学家一直在使用分子数据来快速描述新的青蛙和蝾螈谱系，从物种到家庭水平。在已知的约8500种两栖动物中，约有三分之一是在2005年或之后首次描述的。然而，主流物种描述的做法依赖于一个或几个基因是严重缺陷。大多数分类学描述依赖于少数线粒体或核编码基因（称为DNA条形码）。由于一小部分基因的变异往往不能很好地反映种群的真实进化历史，因此过度依赖DNA条形码会扭曲我们对物种多样性和分布的看法。此外，新发现的两栖动物中有很大一部分仅仅是由地理上分开的同一物种的种群组成的，这些种群在所分析的少数基因上存在差异。将这种遗传谱系分裂成多个物种（“系统发育物种”）的持续趋势人为地增加了地球上已确定的物种总数（一个被称为“分类膨胀”的问题），这一缺陷使保护，社会和经济决策复杂化。新兴的基因组数据正在证明这些做法的风险（7）。经常使用的DNA条形码的不可靠性似乎比以前假设的更普遍。任何新的两栖类分类单元大多由线粒体分歧支持，可能是一个“幽灵血统”（即，不是一个真实的现存物种）。此外，它可能隶属于错误的分支，它作为一个“物种”的排名可能是不合适的。它的名字也可能是错误的，因为模式产地（即，该分类单元首次被描述的参考种群）被错误识别（7）。由于这些模糊不清的地方，最近大量的两栖动物物种描述无疑将需要在不久的将来进行耗时的分类学修订。为了减少混淆，我们呼吁在测试新物种假设时对遗传数据进行更谨慎的解释。鉴于其更高的分辨率，基因组数据集最终将恢复任何结构化的人口作为唯一的
Amphibians feature the highest rates of both new species discoveries and species declines among vertebrates worldwide (1). To characterize this diversity faster than it disappears, zoologists have been using molecular data to rapidly describe new frog and salamander lineages, from species to family levels (2). About a third of the approximately 8500 known amphibian species (3) were first described in 2005 or later (4). However, mainstream species description practices relying on one or a few genes are critically flawed. The majority of taxonomic descriptions rely on a few mitochondrial or nuclear-encoding genes (known as DNA barcodes). Because the variation of a small set of genes is often poorly indicative of the true evolutionary history of populations, overreliance on DNA barcodes distorts our perception of species diversity and distributions (5). In addition, a substantial proportion of newly identified amphibians merely consist of populations of the same species separated by geography that differ at the few genes analyzed. The ongoing trend of splitting such genetic lineages into multiple species (“phylogenetic species”) artificially increases the total number of species identified on Earth (an issue known as “taxonomic inflation”), a shortcoming that complicates conservation, social, and economic decision-making (6). Emerging genomic data are demonstrating the risks of these practices (7). The unreliability of frequently used DNA barcodes appears to be more common than previously assumed. Any new amphibian taxon supported mostly by mitochondrial divergence could be a “ghost lineage”(ie, not a real extant species). Furthermore, it might be affiliated to the wrong clade, and its rank as a “species” might be inappropriate. Its name might also be mistaken because the type locality (ie, the reference population where the taxon was first described) was misidentified (7).Because of these ambiguities, the massive number of recent amphibian species descriptions will undoubtedly require time-consuming taxonomic revisions in the near future. To limit the confusion, we call for more cautious interpretations of genetic data in testing new species hypotheses. Given their higher resolution, genomic datasets will ultimately recover any structured population as unique