Stephen Jay Gould argued that replaying the ‘tape of life’ would result in radically different evolutionary outcomes. Recently, biologists and philosophers of science have paid increasing attention to the theoretical importance of convergent evolution—the independent origination of similar biological forms and functions—which many interpret as evidence against Gould’s thesis. In this paper, we examine the evidentiary relevance of convergent evolution for the radical contingency debate. We show that under the right conditions, episodes of convergent evolution can constitute valid natural experiments (...) that support inferences regarding the deep counterfactual stability of macroevolutionary outcomes. However, we argue that proponents of convergence have problematically lumped causally heterogeneous phenomena into a single evidentiary basket, in effect treating all convergent events as if they are of equivalent theoretical import. As a result, the ‘critique from convergent evolution’ fails to engage with key claims of the radical contingency thesis. To remedy this, we develop ways to break down the heterogeneous set of convergent events based on the nature of the generalizations they support. Adopting this more nuanced approach to convergent evolution allows us to differentiate iterated evolutionary outcomes that are probably common among alternative evolutionary histories and subject to law-like generalizations, from those that do little to undermine and may even support, the Gouldian view of life. (shrink)

Les efforts pour définir la vie se sont intensifiés ces dernières années dans les sciences biologiques. Partant d’une interrogation sur les motivations qui président à ces efforts, nous montrons que l’on doit distinguer deux projets qui s’exposent à des difficultés philosophiques très différentes : ceux présentant l’obtention d’une définition de la vie comme un moyen nécessaire pour l’enquête scientifique ; ceux qui pensent celle-ci comme une fin. Puis nous analysons les usages qui sont faits du terme « vie ». Tandis (...) que l’ensemble des analyses l’ont considéré comme un terme de classe dont les organismes seraient des instances, nous montrons qu’en pratique il existe un second usage implicite de ce terme : dans certains contextes « vie » sert à désigner un individu dont les organismes sont des parties. (shrink)