Department of Biological Sciences, 3616 Trousdale Parkway, University of Southern California, Los Angeles, CA 90089-0371, USA.
Department of Biological Sciences, 3616 Trousdale Parkway, University of Southern California, Los Angeles, CA 90089-0371, USA.
Trends Microbiol. 2019 Mar;27(3):197-205. doi: 10.1016/j.tim.2018.10.009. Epub 2018 Nov 16.
Documenting the immense diversity of single-celled, eukaryotic organisms (protists) has been a formidable challenge for ecologists. These species were originally defined by morphological criteria, but shortcomings of the morphospecies concept, and a bewildering array of sizes and cellular attributes, has made constructing a taxonomy that is useful for ecologists nearly impossible. Consequently, physiological and genetic information has been integrated to address these shortcomings, and to develop the framework of a unifying taxonomy. DNA sequence information, in particular, has revolutionized studies of protistan diversity. However, the exponential increase in sequence-based protistan species richness published from field surveys in recent years raises the question of whether we have moved beyond characterizing species-level diversity and begun to reveal intraspecies diversity. The answer to that question appears to be 'yes', at least for some protistan lineages. The need to document such microdiversity may be justified, but it is important for protistologists to recognize and acknowledge that possibility, and its consequences.
记录单细胞真核生物（原生生物）的巨大多样性一直是生态学家面临的巨大挑战。这些物种最初是根据形态学标准定义的，但形态种概念的缺点，以及令人眼花缭乱的大小和细胞属性，使得构建对生态学家有用的分类法几乎不可能。因此，生理和遗传信息已被整合以解决这些缺点，并开发出统一分类法的框架。特别是 DNA 序列信息，彻底改变了对原生生物多样性的研究。然而，近年来野外调查中基于序列的原生生物物种丰富度的指数增长提出了一个问题，即我们是否已经超越了描述物种水平的多样性，开始揭示种内多样性。对于某些原生生物谱系，答案似乎是肯定的。记录这种微观多样性的必要性可能是合理的，但原生生物学家有必要认识到并承认这种可能性及其后果。
