Evolutionary biology is striking for its ability to explain a large and diverse range of empirical phenomena on the basis of a few general theoretical principles. This article offers a philosophical perspective on the way that evolutionary biology has come to achieve such impressive generality, by focusing on “the strategy of endogenization”. This strategy involves devising evolutionary explanations for biological features that were originally part of the background conditions, or scaffolding, against which such explanations take place. Where successful, the strategy (...) moves biology a step closer to the ideal of explaining as much as possible from evolutionary first principles. The strategy of endogenization is illustrated through a series of biological examples, historical and recent, and its philosophical implications are explored. (shrink)

In order to introduce protists to philosophers, we outline the diversity, classification, and evolutionary importance of these eukaryotic microorganisms. We argue that an evolutionary understanding of protists is crucial for understanding eukaryotes in general. More specifically, evolutionary protistology shows how the emphasis on understanding evolutionary phenomena through a phylogeny-based comparative approach constrains and underpins any more abstract account of why certain organismal features evolved in the early history of eukaryotes. We focus on three crucial episodes of this history: the origins (...) of multicellularity, the origin of sex, and the origin of the eukaryote cell. Despite ongoing uncertainty about where the root of the eukaryote tree lies, and residual questions about the precise endosymbioses that have produced a diversity of photosynthesizing eukaryotes, evolutionary protistology has illuminated with considerable clarity many aspects of protist evolution. Our main message in light of evolutionary protistology is that these ‘other eukaryotes’ are in fact the organisms through which the rest of the eukaryotes should be understood. (shrink)

The model of major transitions in evolution devised by Maynard Smith and Szathmáry has exerted tremendous influence over evolutionary theorists. Although MTE has been criticized for inconsistently combining different types of event, its ongoing appeal lies in depicting hierarchical increases in complexity by means of evolutionary transitions in individuality. In this paper, we consider the implications of major evolutionary events overlooked by MTE and its ETI-oriented successors, specifically the biological oxygenation of Earth, and the acquisitions of mitochondria and plastids. By (...) reflecting on these missed events, we reveal a central philosophical disagreement over the explanatory goals of major transitions theory that has yet to be made explicit in the literature. We go on to argue that this philosophical disagreement is only reinforced by Szathmáry’s recent revisions of MTE in the form of MTE 2.0. This finding motivates us to propose an alternative explanatory strategy: specifically, an interactionist metabolic perspective on major transitions. A metabolic framework not only avoids many of the criticisms that beset classic and revised MTE models, but also accommodates missing events and provides crucial explanatory components for standard major transitions. Although we do not provide a full-blown alternative theory and do not claim to achieve unity, we explain why foregrounding metabolism is crucial for any attempt to capture the major turning points in evolution, and why it does not lead to unmanageable pluralism. (shrink)

There is a worry that the ‘major transitions in evolution’ represent an arbitrary group of events. This worry is warranted, and we show why. We argue that the transition to a new level of hierarchy necessarily involves a nonselectionist chance process. Thus any unified theory of evolutionary transitions must be more like a general theory of fortuitous luck, rather than a rigid formulation of expected events. We provide a systematic account of evolutionary transitions based on a second-order regularity of chance (...) events, as stipulated by the ZFEL (Zero Force Evolutionary Law). And in doing so, we make evolutionary transitions explainable and predictable, and so not entirely contingent after all. (shrink)