SubBio Lab, Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia.
Department of Aquatic Ecology, Eawag, Dübendorf, Switzerland.
Mol Ecol. 2018 Feb;27(3):613-635. doi: 10.1111/mec.14486. Epub 2018 Feb 16.
The species concept is the cornerstone of biodiversity science, and any paradigm shift in the delimitation of species affects many research fields. Many biologists now are embracing a new "species" paradigm as separately evolving populations using different delimitation criteria. Individual criteria can emerge during different periods of speciation; some may never evolve. As such, a paradigm shift in the species concept relates to this inherent heterogeneity in the speciation process and species category-which is fundamentally overlooked in biodiversity research. Cryptic species fall within this paradigm shift: they are continuously being reported from diverse animal phyla but are poorly considered in current tests of ecological and evolutionary theory. The aim of this review is to integrate cryptic species in biodiversity science. In the first section, we address that the absence of morphological diversification is an evolutionary phenomenon, a "process" counterpart to the long-studied mechanisms of morphological diversification. In the next section regarding taxonomy, we show that molecular delimitation of cryptic species is heavily biased towards distance-based methods. We also stress the importance of formally naming of cryptic species for better integration into research fields that use species as units of analysis. Finally, we show that incorporating cryptic species leads to novel insights regarding biodiversity patterns and processes, including large-scale biodiversity assessments, geographic variation in species distribution and species coexistence. It is time for incorporating multicriteria species approaches aiming to understand speciation across space and taxa, thus allowing integration into biodiversity conservation while accommodating for species uncertainty.
物种概念是生物多样性科学的基石，任何物种界定范式的转变都会影响到许多研究领域。许多生物学家现在正在接受一个新的“物种”范式，即将使用不同界定标准的独立进化群体视为不同的物种。个别标准可能会在物种形成的不同时期出现；有些可能永远不会进化。因此，物种概念的范式转变与物种形成过程和物种类别的固有异质性有关，而这在生物多样性研究中基本上被忽视了。隐种就属于这种范式转变：它们不断在不同的动物门中被报道，但在当前对生态和进化理论的检验中却被忽视。本综述的目的是将隐种纳入生物多样性科学。在第一部分中，我们指出形态多样化的缺失是一种进化现象，是对长期研究的形态多样化机制的“过程”对应。在接下来的分类学部分中，我们表明隐种的分子界定严重偏向于基于距离的方法。我们还强调了正式命名隐种的重要性，以便更好地将其纳入以物种为分析单位的研究领域。最后，我们表明，纳入隐种可以对生物多样性模式和过程产生新的认识，包括大规模的生物多样性评估、物种分布的地理变异和物种共存。现在是时候采用多标准物种方法来理解跨空间和分类群的物种形成，从而允许将其纳入生物多样性保护，同时适应物种不确定性。
