A persistent boast of the historical approach to functions is that functional properties are normative. The claim is that a token trait retains its functional status even when it is defective, diseased, or damaged and consequently unable to perform the relevant task. This is because historical functional categories are defined in terms of some sort of historical success -- success in natural selection, typically -- which imposes a norm upon the performance of descendent tokens. Descendents thus are supposed to perform (...) the associated task even when they cannot. The conceit, then, is that malfunctions are explicable in terms of historical success. The aim of this paper is to challenge this conceit. My thesis is that the historical approach to functions lacks the resources with which to account for the possibility of malfunctions. If functional types are defined in terms of historical success, then tokens that lack the defining property due to defect, and tokens that have lost the defining property due to disease or damage, are excluded from the functional category. Historically based malfunctions, in consequence, are impossible. The historical approach is no better than its non-historical competitors in accounting for the presumed normativity of functional properties. (shrink)

The subject of this paper, Excuses, is one not to be treated, but only to be introduced, within such limits. It is, or might be, the name of a whole branch, even a ramiculated branch, of philosophy, or at least of one fashion of philosophy. I shall try, therefore, first to state what the subject is, why it is worth studying, and how it may be studied, all this at a regrettably lofty level: and then I shall illustrate, in more (...) congenial but desultory detail, some of the methods to be used, together with their limitations, and some of the unexpected results to be expected and lessons to be learned. Much, of course, of the amusement, and of the instruction, comes in drawing the coverts of the microglot, in hounding down the minutiae, and to this I can do no more here than incite you. But I owe it to the subject to say, that it has long afforded me what philosophy is so often thought, and made, barren of -- the fun of discovery, the pleasures of co-operation, and the satisfaction of reaching agreement. (shrink)

Among the liveliest disputes in evolutionary biology today are disputes concerning the role of chance in evolution--more specifically, disputes concerning the relative evolutionary importance of natural selection vs. so-called "random drift". The following discussion is an attempt to sort out some of the broad issues involved in those disputes. In the first half of this paper, I try to explain the differences between evolution by natural selection and evolution by random drift. On some common construals of "natural selection", those two (...) modes of evolution are completely indistinguishable. Even on a proper construal of "natural selection", it is difficult to distinguish between the "improbable results of natural selection" and evolution by random drift. In the second half of this paper, I discuss the variety of positions taken by evolutionists with respect to the evolutionary importance of random drift vs. natural selection. I will then consider the variety of issues in question in terms of a conceptual distinction often used to describe the rise of probabilistic thinking in the sciences. I will argue, in particular, that what is going on here is not, as might appear at first sight, just another dispute about the desirability of "stochastic" vs. "deterministic" theories. Modern evolutionists do not argue so much about whether evolution is stochastic, but about how stochastic it is. (shrink)

Philosophers of evolutionary biology favor the so-called etiological concept of function according to which the function of a trait is its evolutionary purpose, defined as the effect for which that trait was favored by natural selection. We term this the selected effect (SE) analysis of function. An alternative account of function was introduced by Robert Cummins in a non-evolutionary and non-purposive context. Cummins''s account has received attention but little support from philosophers of biology. This paper will show that a similar (...) non-purposive concept of function, which we term causal role (CR) function, is crucial to certain research programs in evolutionary biology, and that philosophical criticisms of Cummins''s concept are ineffective in this scientific context. Specifically, we demonstrate that CR functions are a vital and ineliminable part of research in comparative and functional anatomy, and that biological categories used by anatomists are not defined by the application of SE functional analysis. Causal role functions are non-historically defined, but may themselves be used in an historical analysis. Furthermore, we show that a philosophical insistence on the primary of SE functions places practicing biologists in an untenable position, as such functions can rarely be demonstrated (in contrast to CR functions). Biologists who study the form and function of organismal design recognize that it is virtually impossible to identify the past action of selection on any particular structure retrospectively, a requirement for recognizing SE functions. (shrink)

Cognitive ethologists are in need of a good theoretical framework for attributing intentional states. Heyes and Dickinson (1990) present criteria that they claim are necessary for an intentional explanation of behavior to be justified. They suggest that questions of intentionality can only be investigated under controlled laboratory conditions and they apply their criteria to laboratory experiments to argue that the common behavior of approaching food is not intentional in most animals. We dispute the details of their argument and interpretation of (...) the laboratory experiments. While criteria such as those suggested have a role to play in comparative studies of cognition, both laboratory and field studies are important for assessing the applicability of intentional explanations across different taxa. (shrink)

Biological functions are dispositions or effects a trait has which explain the recent maintenance of the trait under natural selection. This is the "modern history" approach to functions. The approach is historical because to ascribe a function is to make a claim about the past, but the relevant past is the recent past; modern history rather than ancient.

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I examine the relationship between evolutionary definitions of altruism that are based on fitness effects and psychological definitions that are based on the motives of the actor. I show that evolutionary altruism can be motivated by proximate mechanisms that are psychologically either altruistic or selfish. I also show that evolutionary definitions do rely upon motives as a metaphor in which the outcome of natural selection is compared to the decisions of a psychologically selfish (or altruistic) individual. Ignoring the precise nature (...) of both psychological and evolutionary definitions has obscured many important issues, including the biological roots of psychological altruism. (shrink)

Altruistic behavior is often regarded as sociobiology''s most central theoretical problem, but is it? Altruism in biology, bioaltruism, has many meanings, which can be grouped into two categories. The first I will callcommon bioaltruism. It is primarily of ethological relevance. The second,evolutionary bioaltruism, is a special category in evolutionary respects in that it may indeed pose a problem for evolutionary theory. These categories are logically independent. Moreover, both of them are logically different from altruism in its everyday psychological or moral (...) sense. Sociobiological examples of bioaltruistic behavior concern bioaltruism in the first sense only, so the theoretical problem altruism is supposed to pose, is indeed nothing but a theoretical problem and the bioaltruism that actually occurs has no evolutionary relevance. Nevertheless, evolutionary theory is relevant to our understanding of the possibility of common bioaltruism, and that possibility — even though bioaltruism is conceptually different from ethical altruism — is relevant for ethicists: it sheds light on what we can ask people to do or not to do. (shrink)

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.

Just as there are rational requirements on thought, there are rational requirements on action. This book defends a conception of ethics, and a related conception of human nature, according to which altruism is included among the basic rational requirements on desire and action. Altruism itself depends on the recognition of the reality of other persons, and on the equivalent capacity to regard oneself as merely one individual among many.

In this essay I defend functional explanations in sociobiology against the charge that they are exercises in speculative story-telling. I distinguish proximate and ultimate biological functions, and discuss their role in functional explanations. I characterize functional explanations as a kind of "consequence explanation", and argue that sociobiologists need to justify a "functional fact" in addition to a "consequence law". Two methods used to supply evidence for functional hypotheses, the technique of optimality analyses and the comparative method, are discussed and illustrated (...) with examples. I argue that adequate evidence for hypothesis about the function of a trait can be provided by the method of comparison, but not by optimality analyses. The comparative method contains an inductive phase that provides independent warrant for, and so serves to establish the high probability of, functional hypotheses. Independent warrant cannot be provided by optimality analyses alone: the model-building approach itself mandates the sacrifice of the truth of a hypothesis to its predictive power. I conclude that while the sociobiologist may wish to employ the optimality analysis as a heuristic strategy, reliable functional explanations are better sought through the use of the comparative method. (shrink)

A model is presented to account for the natural selection of what is termed reciprocally altruistic behavior. The model shows how selection can operate -against the cheater (non-reciprocator) in the system. Three instances of altruistic behavior are discussed, the evolution of which the model can explain: (1) behavior involved in cleaning symbioses; (2) warning cries in birds: and (3) human reciprocal altruism. Regarding human reciprocal altruism, it is shown that the details of the psychological system that regulates this altruism can (...) be explained by the model. Specifically, friendship,d islike, moralistic aggression, gratitude, sympathy, trust, suspicion, trustworthiness, aspects of guilt, and some forms of dishonesty and hypocrisy can be explained as important adaptations to regulate the altruistic system. Each individual human is seen as possessing altruistic and cheating tendencies, the expression of which is sensitive to developmental variables that were selected to set the tendencies at a balance appropriate to the local social and ecological environment. (shrink)