General Botany, University Duisburg-Essen, Essen, Germany.
Eur J Protistol. 2012 May;48(2):96-102. doi: 10.1016/j.ejop.2011.11.004. Epub 2011 Dec 29.
This paper summarises the Symposium 'Concepts in Protistology', during the VI European Congress of Protistology, Berlin, 25-29 July 2011. There is an increasing focus on cataloguing the number of species on earth, species barcoding initiatives, and the increasing need to reconcile molecular with morphological data in protists within a taxonomic framework. We identify several obstructions to defining species in protists, including the high incidence of asexuality, high levels of both morphological conservation and evolutionary convergence, high levels of genetic diversity that cannot so far be correlated with phenotypic characters, conflicting signals between both genetic and phenotypic taxonomic markers, and different requirements and challenges of species definition in different protist groups. We assert that there is no species 'category' for protists, and recommend that a working definition of species is clarified on a case-by-case basis. Thus, a consensus approach may emerge within protist groups, but any one approach is unlikely to encompass a wide phylogenetic range. However, as long as clarity of intent and method is maintained, the utility of the term 'species' in protists will also be maintained as a reproducible and convenient (if artificial) way of referring to particular lineages within a tightly defined context.
本文总结了 2011 年 7 月 25 日至 29 日在柏林举行的第六届欧洲原生动物学大会上的研讨会“原生动物学概念”。人们越来越关注对地球上物种数量的编目、物种条码倡议，以及在分类学框架内越来越需要协调原生动物的分子与形态数据。我们确定了在原生动物中定义物种的几个障碍，包括无性繁殖的高发率、形态保守性和进化趋同的高水平、无法与表型特征相关联的高水平遗传多样性、遗传和表型分类标记之间相互冲突的信号，以及不同原生动物群体对物种定义的不同要求和挑战。我们断言原生动物中没有物种“范畴”，并建议在具体情况下澄清物种的工作定义。因此，在原生动物群体中可能会出现共识方法，但任何一种方法都不太可能涵盖广泛的系统发育范围。然而，只要保持意图和方法的明确性，“物种”一词在原生动物中的实用性也将得到保持，因为它是在严格定义的上下文中指代特定谱系的一种可重复且方便（如果是人为的话）的方式。
