Peter Godfrey-Smith

A number of recent discussions have argued that George Price's equationfor representing evolutionary change is a powerful and illuminatingtool, especially in the context of debates about multiple levels ofselection. Our paper dissects Price's equation in detail, and comparesit to another statistical tool: the calculation and comparison ofaverage fitnesses. The relations between Price's equation and equationsfor evolutionary change using average fitness are closer than issometimes supposed. The two approaches achieve a similar kind ofstatistical summary of one generation of change, and they achieve thisvia a similar loss of information about the underlying fitnessstructure.

Group-structured populations, of the kind prominent in discussions of multilevel selection, are contrasted with ‘neighbor-structured’ populations. I argue that it is a necessary condition on multilevel description of a selection process that there should be a nonarbitrary division of the population into equivalence classes (or an approximation to this situation). The discussion is focused via comparisons between two famous problem cases involving group structure (altruism and heterozygote advantage) and two neighbor-structured cases that resemble them. Conclusions are also drawn about the role of correlated interaction in the evolution of altruism. 1 Introduction 2 Two Kinds of Population Structure 3 Objections and Replies 4 Particles on a Line 5 Conclusion Appendix: Neighborhoods and Selection CiteULike    Connotea    Del.icio.us    What's this?

We present a dynamic model of the evolution of communication in a Lewis signaling game while systematically varying the degree of common interest between sender and receiver. We show that the level of common interest between sender and receiver is strongly predictive of the amount of information transferred between them. We also discuss a set of rare but interesting cases in which common interest is almost entirely absent, yet substantial information transfer persists in a *cheap talk* regime, and offer a diagnosis of how this may arise.

Altruism is generally understood to be behavior that benefits others at a personal cost to the behaving individual. However, within evolutionary biology, different authors have interpreted the concept of altruism differently, leading to dissimilar predictions about the evolution of altruistic behavior. Generally, different interpretations diverge on which party receives the benefit from altruism and on how the cost of altruism is assessed. Using a simple trait-group framework, we delineate the assumptions underlying different interpretations and show how they relate to one another. We feel that a thorough examination of the connections between interpretations not only reveals why different authors have arrived at disparate conclusions about altruism, but also illuminates the conditions that are likely to favor the evolution of altruism.

The "tangle" referred to in my title is a special set of problems that arise in understanding the evolution of mental representation. These are problems over and above those involved in reconstructing evolutionary histories in general, over and above those involved in dealing with human evolution, and even over and above those involved in tackling the evolution of other human psychological traits. I am talking about a peculiar and troublesome set of interactions and possibilities, linked to long-standing debates about the status of folk psychology and the nature of semantic properties

Why do octopuses matter to philosophy? They matter to the part of philosophy concerned with the mind. To see why, we step back and think about the evolutionary connections between all living things. Biologists think of these relationships in terms of a tree of life. This is a huge tree-like pattern, marking which species are close relatives and which are distantly connected. The vertebrates form one branch of the tree, and that is where we find nearly all the animals with large and complex brains. These include ourselves, other mammals, and birds. In evolutionary terms, these are all cousins. In the huge area of the tree containing other animals, invertebrates, there is only one small branch where we also find large brains. This branch contains the cephalopods – octopuses, cuttlefish, and squid. Large nervous systems evolved separately on these two branches, and nowhere else. Octopuses are a separate experiment in the evolution of the mind. Meeting an octopus is like meeting an intelligent alien. So what did this experiment produce? Here is one thing. The nervous system of an octopus is less centralized than ours. In fact, more than half of the octopus' neurons are not in the animal's central "brain" at all, but in the eight arms. It is as if each arm has a mind of its own. Or perhaps in an octopus we see intelligence without a unified self

Sometimes themes can be found in common across very different systems in which change occurs. Imre Lakatos developed a theory of change in science, and one involving entities visible at different levels. There are theories defended at a particular time, and there are also research programs, larger units that bundle together a sequence of related theories and within which many scientists may work. Research programs are competing higher-level units within a scientific field. Scientific change involves change within research programs, and change in the ensemble of research programs present at a time, where some will be growing, some shrinking, some progressing, some degenerating. These are also themes in biological evolution. Recent biology has often found itself dealing with the relation between change at a level of "collectives" – such as organisms like us – and change at a lower level – the level of cells, genes, and other evolving parts. This work is continuous with an older discussion, one that arose when biological evolution was no more than a vague speculation, round the beginning of the 19th century. What is the living individual? What is the basic unit of life or living organization? Questions like this were pursued by Goethe, by Erasmus Darwin, the grandfather of Charles, and many others. Initially it was plants, especially, that were seen to raise these problems, and then newly described marine animals with strange life cycles. The discussion was influenced by the rise of the cell theory in the early 19th century, but some writers looked for individuals well below the level of the cell

Debate about adaptationism in biology continues, in part because within “the” problem of assessing adaptationism, three distinct problems are mixed together. The three problems concern the assessment of three distinct adaptationist positions, each of which asserts the central importance of adaptation and natural selection to the study of evolution, but conceives this importance in a different way. As there are three kinds of adaptationism, there are three distinct "anti-adaptationist" positions as well. Or putting it more formally, there are three different dimensions here, and strongly adaptationist views, strongly anti-adaptationist views, and moderate views are possible for each dimension.

“Triviality arguments” against functionalism in the philosophy of mind hold that the claim that some complex physical system exhibits a given functional organization is either trivial or has much less content than is usually supposed. I survey several earlier arguments of this kind, and present a new one that overcomes some limitations in the earlier arguments. Resisting triviality arguments is possible, but requires functionalists to revise popular views about the “autonomy” of functional description.

Metaphysics is once again a thriving subdiscipline within philosophy, despite a long tradition of challenges to the very viability of the metaphysical enterprise. The criticisms have not so much been satisfactorily answered, as shouldered aside by the vigorous development of the field. Some focused meta-theoretic discussion has recently arisen within mainstream metaphysics.1 The present paper is written more from an outsider's vantage point. I attempt to give a new meta-theory for some parts of metaphysics. The central claim is that much metaphysical work, especially of the contemporary systematic kind, might best be understood as model-building, in a specific sense of this term that draws on recent philosophy of science.

How does science work? Does it tell us what the world is "really" like? What makes it different from other ways of understanding the universe? In Theory and Reality , Peter Godfrey-Smith addresses these questions by taking the reader on a grand tour of one hundred years of debate about science. The result is a completely accessible introduction to the main themes of the philosophy of science. Intended for undergraduates and general readers with no prior background in philosophy, Theory and Reality covers logical positivism the problems of induction and confirmation Karl Popper's theory of science Thomas Kuhn and "scientific revolutions" the views of Imre Lakatos, Larry Laudan, and Paul Feyerabend and challenges to the field from sociology of science, feminism, and science studies. The book then looks in more detail at some specific problems and theories, including scientific realism, the theory-ladeness of observation, scientific explanation, and Bayesianism. Finally, Godfrey-Smith defends a form of philosophical naturalism as the best way to solve the main problems in the field. Throughout the text he points out connections between philosophical debates and wider discussions about science in recent decades, such as the infamous "science wars." Examples and asides engage the beginning student a glossary of terms explains key concepts and suggestions for further reading are included at the end of each chapter. However, this is a textbook that doesn't feel like a textbook because it captures the historical drama of changes in how science has been conceived over the last one hundred years. Like no other text in this field, Theory and Reality combines a survey of recent history of the philosophy of science with current key debates in language that any beginning scholar or critical reader can follow.

Drawing on models of communication due to Lewis and Skyrms, I contrast sender-receiver systems as they appear within and between organisms, and as they function in the bridging of space and time. Within the organism, memory can be seen as the sending of messages over time, communication between stages as opposed to spatial parts. Psychological memory and genetic memory are compared with respect to their relations to a sender-receiver model. Some puzzles about “genetic information” can be resolved by seeing the genome as a cell-level memory with no sender

A model of “ephemeral” population structure is presented that applies not only to biological systems in which discrete groups form but also to networks without group boundaries. The evolution of altruistic behaviors is discussed. Nonrandom interaction and nonlinear fitness structures are modeled; together, these factors can produce stable polymorphisms of altruistic and selfish types, as well as bistability. Empirical applications of the model may be found in microbes, marine invertebrates, annual plants, and other organisms.

A “sender–receiver” framework based on models developed in several fields can provide a general treatment of communicative and symbolic phenomena, replacing traditional semiotic theories that have failed to live up to the hopes of their advocates. Sender–receiver models have mostly been applied to linguistic behavior, gestures, and other ephemeral interactions between individuals. I look at the application of this framework to enduring artifacts, including pictures, using indigenous rock art in Australia as a case study.

Research in archaeology and anthropology on the evolution of modern patterns of human behavior often makes use of general theories of signs, usually derived from semiotics. Recent work generalizing David Lewis’ 1969 model of signaling provides a better theory of signs than those currently in use. This approach is based on the coevolution of behaviors of sign production and sign interpretation. I discuss these models and then look at applications to human prehistoric behavior, focusing on body ornamentation, tools, and other artifacts.