The authors demonstrate that unselfish behavior is in fact an important feature of both biological and human nature. Their book provides a panoramic view of altruism throughout the animal kingdom--from self-sacrificing parasites to the human capacity for selflessness--even as it explains the evolutionary sense of such behavior.

The book presents a new way of understanding Darwinism and evolution by natural selection, combining work in biology, philosophy, and other fields.

Kant's attempt to establish the principles behind the faculty of judgment remains one of the most important works on human reason.

Does natural selection act primarily on individual organisms, on groups, on genes, or on whole species? The question of levels of selection - on which biologists and philosophers have long disagreed - is central to evolutionary theory and to the philosophy of biology. Samir Okasha's comprehensive analysis gives a clear account of the philosophical issues at stake in the current debate.

What makes a biological entity an individual? Jack Wilson shows that past philosophers have failed to explicate the conditions an entity must satisfy to be a living individual. He explores the reason for this failure and explains why we should limit ourselves to examples involving real organisms rather than thought experiments. This book explores and resolves paradoxes that arise when one applies past notions of individuality to biological examples beyond the conventional range and presents an analysis of identity and persistence. (...) The book's main purpose is to bring together two lines of research, theoretical biology and metaphysics, which have dealt with the same subject in isolation from one another. Wilson explains an alternative theory about biological individuality which solves problems which cannot be addressed by either field alone. He presents a more fine-grained vocabulary of individuation based on diverse kinds of living things, allowing him to clarify previously muddled disputes about individuality in biology. (shrink)

Developmental systems theory (DST) expands the unit of replication from genes to whole systems of developmental resources, which DST interprets in terms of cycling developmental processes. Expansion seems required by DST's argument against privileging genes in evolutionary and developmental explanations of organic traits. DST and the expanded replicator brook no distinction between biological and cultural evolution. However, by endorsing a single expanded unit of inheritance and leaving the classical molecular notion of gene intact, DST achieves only a nominal reunification of (...) heredity and development. I argue that an alternative conceptualization of inheritance denies the classical opposition of genetics and development while avoiding the singularity inherent in the replicator concept. It also yields a new unit--the reproducer--which genuinely integrates genetic and developmental perspectives. The reproducer concept articulates the non-separability of "genetic" and "developmental" roles in units of heredity, development, and evolution. DST reformulated in terms of reproducers rather than replicators preserves an empirically interesting distinction between cultural and biological evolution. (shrink)

That biology provides explanations is not open to doubt. But how it does so must be a vexed question for those who deny that biology embodies laws or other generalizations with the sort of explanatory force that the philosophy of science recognizes. The most common response to this problem has involved redefining law so that those grammatically general statements which biologists invoke in explanations can be counted as laws. But this terminological innovation cannot identify the source of biology's explanatory power. (...) I argue that because biological science is historical, the problem of biological explanation can be assimilated to the parallel problem in the philosophy of history, and that the problem was solved by Carl Hempel. All we need to do is recognize that the only laws that biology—in all its compartments from the molecular onward—has or needs are the laws of natural selection. (shrink)

The problem of plant individuality is something which has vexed botanists throughout the ages, with fashion swinging back and forth from treating plants as communities of individuals (Darwin 1800 ; Braun and Stone 1853 ; Münch 1938 ) to treating them as organisms in their own right, and although the latter view has dominated mainstream thought most recently (Harper 1977 ; Cook 1985 ; Ariew and Lewontin 2004 ), a lively debate conducted mostly in Scandinavian journals proves that the issues (...) are far from being resolved (Tuomi and Vuorisalo 1989b ; Fagerström 1992 ; Pan and Price 2001 ). In this paper I settle the matter once and for all, by showing which elements of each side are correct. (shrink)

Two major clarifications have greatly abetted the understanding and fruitful expansion of the theory of natural selection in recent years: the acknowledgment that interactors, not replicators, constitute the causal unit of selection; and the recognition that interactors are Darwinian individuals, and that such individuals exist with potency at several levels of organization (genes, organisms, demes, and species in particular), thus engendering a rich hierarchical theory of selection in contrast with Darwin’s own emphasis on the organismic level. But a piece of (...) the argument has been missing, and individuals at levels distinct from organisms have been denied potency (although granted existence within the undeniable logic of the theory), because they do not achieve individuality with the same devices used by organisms and therefore seem weak by comparison. We show here that different features define Darwinian individuality across scales of size and time. In particular, species-individuals may develop few emergent features as direct adaptations. The interactor approach works with emergent fitnesses, not with emergent features; and species, as a consequence of their different mechanism for achieving individuality (reproductive exclusivity among subparts, that is, among organisms), express many effects from other levels. Organisms, by contrast, suppress upwardly cascading effects, because the organismic style of individuality (by functional integration of subparts) does not permit much competition or differential reproduction of parts from within. Species do not suppress the operation of lower levels; such effects therefore become available as exaptations conferring emergent fitness—a primary source of the different strength that species achieve as effective Darwinian individuals in evolution. (shrink)

The fitness of any evolutionary unit can be understood in terms of its two basic components: fecundity (reproduction) and viability (survival). Trade-offs between these fitness components drive the evolution of life-history traits in extant multicellular organisms. We argue that these trade-offs gain special significance during the transition from unicellular to multicellular life. In particular, the evolution of germ–soma specialization and the emergence of individuality at the cell group (or organism) level are also consequences of trade-offs between the two basic fitness (...) components, or so we argue using a multilevel selection approach. During the origin of multicellularity, we study how the group trade-offs between viability and fecundity are initially determined by the cell level trade-offs, but as the transition proceeds, the fitness trade-offs at the group level depart from those at the cell level. We predict that these trade-offs begin with concave curvature in single-celled organisms but become increasingly convex as group size increases in multicellular organisms. We argue that the increasingly convex curvature of the trade-off function is driven by the cost of reproduction which increases as group size increases. We consider aspects of the biology of the volvocine green algae – which contain both unicellular and multicellular members – to illustrate the principles and conclusions discussed. (shrink)

We are grateful to the commentators for taking the time to respond to our article. Too many interesting and important points have been raised for us to tackle them all in this response, and so in the below we have sought to draw out the major themes. These include problems with both the term ‘ultimate causation’ and the proximate-ultimate causation dichotomy more generally, clarification of the meaning of reciprocal causation, discussion of issues related to the nature of development and phenotypic (...) plasticity and their roles in evolution, and consideration of the need for an extended evolutionary synthesis. (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)

Our intuitive assumption that only organisms are the real individuals in the natural world is at odds with developments in cell biology, ecology, genetics, evolutionary biology, and other fields. Although organisms have served for centuries as nature's paradigmatic individuals, science suggests that organisms are only one of the many ways in which the natural world could be organized. When living beings work together--as in ant colonies, beehives, and bacteria-metazoan symbiosis--new collective individuals can emerge. In this book, leading scholars consider the (...) biological and philosophical implications of the emergence of these new collective individuals from associations of living beings. The topics they consider range from metaphysical issues to biological research on natural selection, sociobiology, and symbiosis. (shrink)

Ever since the publication of Richard Dawkins' The Selfish Gene, a book for the lay reader that popularized the ideas of influential evolutionary biologists like William Hamilton and George Williams, there has been much discussion of so-called "universal Darwinism". Dawkins' dual aim was to reduce evolutionary phenomena to the level of the gene, while at the same time abstracting the Darwinian process of natural selection of "replicators" and making it into something that would apply beyond the domain of biology.

Richard Lewontin's (1970) early work on the units of selection initiated the conceptual and theoretical investigations that have led to the hierarchical perspective on selection that has reached near consensus status today. This paper explores other aspects of his work, work on what he termed continuity and quasi-independence, that connect to contemporary explorations of modularity in development and evolution. I characterize such modules and argue that they are the true units of selection in that they are what evolution by natural (...) selection individuates, selects among, and transforms. (shrink)