Bourrat Pierrick, Griffiths Paul E
Department of Philosophy, Macquarie University, North Ryde, NSW, 2109, Australia.
School of History and Philosophy of Science, University of Sydney, Main Quadrangle A14, Sydney, NSW, 2006, Australia.
Hist Philos Life Sci. 2018 May 14;40(2):33. doi: 10.1007/s40656-018-0194-1.
We assess the arguments for recognising functionally integrated multispecies consortia as genuine biological individuals, including cases of so-called 'holobionts'. We provide two examples in which the same core biochemical processes that sustain life are distributed across a consortium of individuals of different species. Although the same chemistry features in both examples, proponents of the holobiont as unit of evolution would recognize one of the two cases as a multispecies individual whilst they would consider the other as a compelling case of ecological dependence between separate individuals. Some widely used arguments in support of the 'holobiont' concept apply equally to both cases, suggesting that those arguments have misidentified what is at stake when seeking to identify a new level of biological individuality. One important aspect of biological individuality is evolutionary individuality. In line with other work on the evolution of individuality, we show that our cases can be distinguished by focusing on the fitness alignment between the partners of the consortia. We conclude that much of the evidence currently presented for the ubiquity and importance of multi-species individuals is simply not to the point, at least unless the issue of biological individuality is firmly divorced from the question of evolutionary individuality.
我们评估了将功能整合的多物种聚生体视为真正生物个体的论据，包括所谓“全生物”的案例。我们提供了两个例子，其中维持生命的相同核心生化过程分布在不同物种个体的聚生体中。尽管两个例子中的化学特征相同，但将全生物视为进化单位的支持者会将这两个案例中的一个视为多物种个体，而将另一个视为不同个体之间生态依赖的有力案例。一些广泛用于支持“全生物”概念的论据对这两个案例同样适用，这表明这些论据在试图确定生物个体性的新层次时，错误地识别了关键所在。生物个体性的一个重要方面是进化个体性。与关于个体性进化的其他研究一致，我们表明可以通过关注聚生体伙伴之间的适应性匹配来区分我们的案例。我们得出结论，目前提出的许多关于多物种个体的普遍性和重要性的证据根本没有切中要害，至少除非生物个体性问题与进化个体性问题完全分开。
