We address three fundamental questions: What does it mean for an entity to be living? What is the role of inter-organismic collaboration in evolution? What is a biological individual? Our central argument is that life arises when lineage-forming entities collaborate in metabolism. By conceiving of metabolism as a collaborative process performed by functional wholes, which are associations of a variety of lineage-forming entities, we avoid the standard tension between reproduction and metabolism in discussions of life – a tension particularly evident (...) in discussions of whether viruses are alive. Our perspective assumes no sharp distinction between life and non-life, and does not equate life exclusively with cellular or organismal status. We reach this conclusion through an analysis of the capabilities of a spectrum of biological entities, in which we include the pivotal case of viruses as well as prions, plasmids, organelles, intracellular and extracellular symbionts, unicellular and multicellular life-forms. The usual criterion for classifying many of the entities of our continuum as non-living is autonomy. This emphasis on autonomy is problematic, however, because even paradigmatic biological individuals, such as large animals, are dependent on symbiotic associations with many other organisms. These composite individuals constitute the metabolic wholes on which selection acts. Finally, our account treats cooperation and competition not as polar opposites but as points on a continuum of collaboration. We suggest that competitive relations are a transitional state, with multi-lineage metabolic wholes eventually outcompeting selfish competitors, and that this process sometimes leads to the emergence of new types or levels of wholes. Our view of life as a continuum of variably structured collaborative systems leaves open the possibility that a variety of forms of organized matter – from chemical systems to ecosystems – might be usefully understood as living entities. (shrink)

If a person's head moves, she may or may not have moved her head, and, if she did move it, she may have actively performed the movement of her head or merely, by doing something else, caused a passive movement. And, if she performed the movement, she might have done so intentionally or not. This short array of contrasts (and others like them) has motivated questions about the nature, variety, and identity of action. Beyond the matter of her moving, when (...) the person moves her head, she may be indicating agreement or shaking an insect off her ear. Should we think of the consequences, conventional or causal, of physical behavior as constituents of an action distinct from but ‘generated by’ the movement? Or should we think that there is a single action describable in a host of ways? Also, actions, in even the most minimal sense, seem to be essentially ‘active’. But, how can we explain what this property amounts to and defend our wavering intuitions about which events fall in the category of the ‘active’ and which do not? (shrink)

Greg Cooper’s The Science of the Struggle for Existence is a must read for those interested in the history and philosophy of ecology and in topics like laws of nature, scientific explanation, and mathematical modeling. If you want to explore some of the metaphysical and methodological challenges that face ecology, there is no better place to go. Thus, this book marks an important moment in the philosophy of ecology. Folks like myself will be responding to it for quite a while. (...) What I find most appealing about the book is just how much there is to argue with. On every page there are interesting ideas presented but which are excitingly controversial. Some will argue with Cooper’s interpretation of the history of ecology. There are parts of the book that empiricists will balk at. You will not be left unstirred. Having said this, Cooper can be longwinded and while you read you should remember patience is a virtue. (shrink)

Though viruses have generally been characterized by their pathogenic and more generally harmful effects, many examples of mutualistic viruses exist. Here I explain how the idea of mutualistic viruses has been defended in recent virology, and I explore four important conceptual and practical consequences of this idea. I ask to what extent this research modifies the way scientists might search for new viruses, our notion of how the host immune system interacts with microbes, the development of new therapeutic approaches, and, (...) finally, the role played by the criterion of autonomy in our understanding of living things. Overall, I suggest that the recognition of mutualistic viruses plays a major role in a wider ongoing revision of our conception of viruses. (shrink)