Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, 90095, USA.
Department of Botany, California Academy of Sciences, San Francisco, CA, 94118, USA.
Sci Rep. 2021 Dec 14;11(1):24013. doi: 10.1038/s41598-021-03419-0.
What we mean by species and whether they have any biological reality has been debated since the early days of evolutionary biology. Some biologists even suggest that plant species are created by taxonomists as a subjective, artificial division of nature. However, the nature of plant species has been rarely tested critically with data while ignoring taxonomy. We integrate phenomic and genomic data collected across hundreds of individuals at a continental scale to investigate this question in Escallonia (Escalloniaceae), a group of plants which includes 40 taxonomic species (the species proposed by taxonomists). We first show that taxonomic species may be questionable as they match poorly to patterns of phenotypic and genetic variation displayed by individuals collected in nature. We then use explicit statistical methods for species delimitation designed for phenotypic and genomic data, and show that plant species do exist in Escallonia as an objective, discrete property of nature independent of taxonomy. We show that such species correspond poorly to current taxonomic species ([Formula: see text]) and that phenomic and genomic data seldom delimit congruent entities ([Formula: see text]). These discrepancies suggest that evolutionary forces additional to gene flow can maintain the cohesion of species. We propose that phenomic and genomic data analyzed on an equal footing build a broader perspective on the nature of plant species by helping delineate different 'types of species'. Our results caution studies which take the accuracy of taxonomic species for granted and challenge the notion of plant species without empirical evidence. Note: A version of the complete manuscript in Spanish is available in the Supplemental Materials.
我们所说的物种以及它们是否具有任何生物学上的真实性，自进化生物学的早期就一直存在争议。一些生物学家甚至认为植物物种是由分类学家创造的，是对自然的主观、人为划分。然而，在忽略分类学的情况下，很少有数据对植物物种的本质进行批判性检验。我们整合了在大陆尺度上数百个个体收集的表型和基因组数据，以研究 Escallonia（Escalloniaceae）中存在的这个问题，该植物群包括 40 个分类物种（分类学家提出的物种）。我们首先表明，分类学物种可能存在问题，因为它们与在自然界中收集的个体表现出的表型和遗传变异模式匹配不佳。然后，我们使用针对表型和基因组数据设计的明确物种界定统计方法，表明植物物种确实存在于 Escallonia 中，是一种独立于分类学的客观离散的自然属性。我们表明，这些物种与当前的分类物种（[公式：见正文]）对应性较差，并且表型和基因组数据很少界定一致的实体（[公式：见正文]）。这些差异表明，除了基因流之外，进化力量可以维持物种的凝聚力。我们提出，在平等的基础上分析表型和基因组数据，可以通过帮助描绘不同的“物种类型”，对植物物种的本质形成更广泛的观点。我们的研究结果提醒那些理所当然地认为分类学物种准确性的研究，并挑战了没有经验证据的植物物种概念。注意：西班牙语版本的完整手稿可在补充材料中找到。
