In this paper, we develop an organizational account that defines biological functions as causal relations subject to closure in living systems, interpreted as the most typical example of organizationally closed and differentiated self-maintaining systems. We argue that this account adequately grounds the teleological and normative dimensions of functions in the current organization of a system, insofar as it provides an explanation for the existence of the function bearer and, at the same time, identifies in a non-arbitrary way the norms that (...) functions are supposed to obey. Accordingly, we suggest that the organizational account combines the etiological and dispositional perspectives in an integrated theoretical framework. IntroductionDispositional ApproachesEtiological TheoriesBiological Self-maintenance Closure, teleology, and normativityOrganizational differentiationFunctions C1: Contributing to the maintenance of the organization C2: Producing the functional trait Implications and Objections Functional versus useful Dysfunctions, side effects, and accidental contributionsProper functions and selected effectsReproductionRelation with other ‘unitarian’ approachesConclusions. (shrink)

argue that natural selection does not explain the genotypic arid phenotypic properties of individuals. On this view, natural selection explains the adaptedness of individuals, not by explaining why the individuals that exist have the adaptations they do, but rather by explaining why the individuals that exist are the ones with those adaptations. This paper argues that this ‘Negative’ view of natural selection ignores the fact that natural selection is a cumulative selection process. So understood, it explains how the genetic sequences (...) that individuals inherit and that are responsible for their complex (and co-adapted) adaptations first arose in the gene-pool. (shrink)

The etiological approach to ‘proper functions’ in biology can be strengthened by relating it to Robert Cummins' general treatment of function ascription. The proper functions of a biological trait are the functions it is assigned in a Cummins-style functional explanation of the fitness of ancestors. These functions figure in selective explanations of the trait. It is also argued that some recent etiological theories include inaccurate accounts of selective explanation in biology. Finally, a generalization of the notion of selective explanation allows (...) an analysis of the proper functions of human artifacts. (shrink)

Natural selection comes in degrees. Some biological traits are subjected to stronger selective force than others, selection on particular traits waxes and wanes over time, and some groups can only undergo an attenuated kind of selective process. This has downstream consequences for any notions that are standardly treated as binary but depend on natural selection. For instance, the proper function of a biological structure can be defined as what caused that structure to be retained by natural selection in the past. (...) We usually think of proper functions in binary terms: storing bile is a function of the gall bladder, but making stones is not. However, if functions arise through natural selection, and natural selection comes in degrees, then a binary approach to proper functions is in tension with the biological facts. In order to resolve this tension, we need to revise our standard accounts of proper function. In particular, we may have to seriously consider the possibility that functions themselves come in degrees, in spite of the ramifications this will have for the way we speak about functions and related concepts such as dysfunction, disease, and teleosemantic content. (shrink)

Our understanding of communication and its evolution has advanced significantly through the study of simple models involving interacting senders and receivers of signals. Many theorists have thought that the resources of mathematical information theory are all that are needed to capture the meaning or content that is being communicated in these systems. However, the way theorists routinely talk about the models implicitly draws on a conception of content that is richer than bare informational content, especially in contexts where false content (...) is important. This article shows that this concept can be made precise by defining a notion of functional content that captures the degree to which different states of the world are involved in stabilizing senders’ and receivers’ use of a signal at equilibrium. A series of case studies is used to contrast functional content with informational content, and to illustrate the explanatory role and limitations of this definition of functional content. _1_ Introduction _2_ Modelling Framework _3_ Two Kinds of Content _3.1_ Informational content _3.2_ Functional content _4_ Cases _4.1_ Case 1: Simplest case _4.2_ Case 2: Partial pooling _4.3_ Case 3: Bottleneck _4.4_ Case 4: Partial common interest _4.5_ Case 5: Deception _4.6_ Case 6: A further problem arising from divergent interests _5_ Discussion Appendix. (shrink)

Over the last 20 years, several philosophers have developed a new approach to biological functions, the organizational approach. This is not a single theory but a family of theories based on the idea that a trait token can acquire a function by virtue of the way it contributes to a complex, organized system and thereby to its own continued persistence as a token. I argue that the organizational approach faces a serious liberality objection. I examine three different ways organizational theorists (...) have tried to avoid that objection and show how they fail. (shrink)

Christie, Brusse, et al. argue that selected effects are insufficient to explain the prevalence of traits when selection is heterogeneous. One could object that it’s useful to ground functions in selected effects so long as selected effects are necessary to explain the prevalence of traits. This raises a challenging question: what justifies singling out selected effects from other factors that are necessary to explain the prevalence of traits when selection is heterogeneous? I consider three answers: selected effects are the only (...) factors that explain the prevalence of traits and (a) can plausibly ground functions; (b) enable biological generalization; and (c) enable representational explanation. I argue that none of these answers is satisfactory. Only the third answer might be able to justify singling out any selected effects at all (when selection is heterogeneous): the small share of selected effects that ground representations of causal particulars. Thus, I agree with Christie, Brusse, et al. that heterogeneous selection is a serious problem for selected effects theories of function. (shrink)

In the target article, Christie, Brusse, et al. argue that selected effect functions do not, in general, explain why a trait exists in a population and, therefore, theories of representational content should not rely on selected effect functions. This response focuses on the claim about functions-for-representation. The role of evolutionary functions in a theory of content is to pick out outcomes that have been systematically stabilized by natural selection. Correctness conditions are conditions involved in explaining how that happened. Selected effect (...) functions can play that role in the complex equilibria that Christie, Brusse, et al. identify. Non-equilibrium cases are also discussed. (shrink)

Christie, Brusse, et al. argue that the selected effects theory of function (SE) doesn’t do what it’s supposed to do: namely, show how functions can be explanatory. They survey some well-known evolutionary dynamics such as arms races, frequency-dependent fitness, and environmental heterogeneity, some of which have been discussed in the functions literature for decades. They argue that SE only seems to work because SE theorists ignore these dynamics. Their argument fails because they misrepresent what functions are supposed to explain and (...) how they’re supposed to do so. One reason for this failure is that they overlook the role of functions in the broader conversation about teleology in biology, one that has been unfolding for over 2000 years. (shrink)

In ‘Are biological traits explained by their “selected effect” functions?’, Christie, Brusse, Bourrat, Takacs, and Griffiths argue that selected effect functions only explain the presence of a trait (or the frequency of a trait in a population) in cases in which the selective environment has been uniform, illustrating their point with cases of coevolution, frequency-dependent selection, and bet-hedging. This commentary suggests that selected effect functions are explanatory even in those cases, and that Christie, Brusse, et al. are mistaken about the (...) explanatory aims of the selected effects theory, criticizing it for failing to do something it never set out to do. (shrink)

Christie, Brusse, et al. claim that the ‘selected effect’ (SE) theory of function is premised on a simplistic view of evolution. In complex evolutionary scenarios, in particular those involving frequency-dependent selection (FDS), the SE theory fails, they argue, since citing a trait’s SE function does not serve to explain why the trait exists. I argue that where FDS leads to a stable equilibrium, at which all individuals’ trait values constitute a ‘best response’ to the rest of the population, the SE (...) theory can be straightforwardly applied. However, matters are different if the evolutionary dynamics do not take the population to a stable equilibrium. (shrink)

The selected effects or ‘etiological’ theory of Proper function is a naturalistic and realist account of biological teleology. It is used to analyse normativity in philosophy of language, philosophy of mind, philosophy of medicine, and elsewhere. The theory has been developed with a simple and intuitive view of natural selection. Traits are selected because of their positive effects on the fitness of the organisms that have them. These ‘selected effects’ are the Proper functions of the traits. Proponents argue that this (...) analysis of biological teleology has the unique advantage that the selected effect function of a trait is also a causal explanation of the trait: the trait exists because it performs this function. We show, however, that selected effect functions as currently defined explain the existence of traits only under highly restrictive assumptions about evolutionary dynamics. In many common scenarios in which traits evolve by natural selection, selected effect functions do not explain those traits. This is because definitions of selected effect function extract from any evolutionary scenario only the information that would be explanatorily relevant in the simple evolutionary scenario implicit in those definitions. When applied to more complex scenarios, selected effect functions omit the key information that is explanatorily relevant in those scenarios. The assumptions required for selected effect functions to be explanatory are particularly unlikely to hold in the domain that its proponents care most about—the evolution of representation. A more adequate selected effects theory of Proper functions may be possible, but will require much greater attention to the structure of actual evolutionary explanations. (shrink)

Dobzhansky argued that biology only makes sense if life on earth has a shared history. But his dictum is often reinterpreted to mean that biology only makes sense in the light of adaptation. Some philosophers of science have argued in this spirit that all work in ‘proximal’ biosciences such as anatomy, physiology and molecular biology must be framed, at least implicitly, by the selection histories of the organisms under study. Others have denied this and have proposed non-evolutionary ways in which (...) biologists can frame these investigations. This paper argues that an evolutionary perspective is indeed necessary, but that it must be a forward-looking perspective informed by a general understanding of the evolutionary process, not a backward-looking perspective informed by the specific evolutionary history of the species being studied. Interestingly, it turns out that there are aspects of proximal biology that even a creationist cannot study except in the light of a theory of their effect on future evolution. (shrink)

Part I [sections 2–4] draws out the conceptual links between modern conceptions of teleology and their Aristotelian predecessor, briefly outlines the mode of functional analysis employed to explicate teleology, and develops the notion of cybernetic organisation in order to distinguish teleonomic and teleomatic systems. Part II is concerned with arriving at a coherent notion of intentional control. Section 5 argues that intentionality is to be understood in terms of the representational properties of cybernetic systems. Following from this, section 6 argues (...) that intentional control needs to be seen as a particular type of relationship between the system and its environment. (shrink)