Twenty years have passed since Gould and Lewontin published their critique of ‘the adaptationist program’ – the tendency of some evolutionary biologists to assume, rather than demonstrate, the operation of natural selection. After the ‘Spandrels paper’, evolutionists were more careful about producing just-so stories based on selection, and paid more attention to a panoply of other processes. Then came reactions against the excesses of the anti-adaptationist movement, which ranged from a complete dismissal of Gould and Lewontin’s contribution to a positive (...) call to overcome the problems. We now have an excellent opportunity for finally affirming a more balanced and pluralistic approach to the study of evolutionary biology. (shrink)
This paper critically examines Jerry Fodor's latest attacks on evolutionary psychology. Contra Leda Cosmides and John Tooby, Fodor argues (i) there is no reason to think that human cognition is a Darwinian adaptation in the first place, and (ii) there is no valid inference from adaptationism about the mind to massive modularity. However, Fodor maintains (iii) that there is a valid inference in the converse direction, from modularity to adaptationism, but (iv) that the language module is an exception (...) to the validity of this inference. I explore Fodor's arguments for each of these claims, and the interrelations between them. I argue that Fodor is incorrect on point (i), correct on point (ii), partially correct on point (iii), and incorrect on point (iv). Overall, his critique fails to show that adopting a broadly Darwinian approach to cognition is intellectually indefensible. (shrink)
Evolutionary psychologists attempt to infer our evolved psychology from the selection pressures present in our ancestral environments. Their use of this inference strategy?often called ?adaptive thinking??is thought to be justified by way of appeal to a rather modest form of adaptationism, according to which the mind's adaptive complexity reveals it to be a product of selection. I argue, on the contrary, that the mind's being an adaptation is only a necessary and not a sufficient condition for the validity of (...) adaptive thinking, and that evolutionary psychology's predictive project is in fact committed to an extremely strong and highly implausible form of adaptationism. According to this ?strong adaptationism,? the macroevolutionary trajectory of a population is determined by, and therefore predictable on the basis of, the selection pressures acting upon it. Not only is this form of adaptationism prima facie highly implausible, it requires making a number of naïve and likely false assumptions concerning the nature of heritable phenotypic variation in natural populations. In particular, it assumes that phenotypic variation is inevitably small in its extent, unbiased in its direction, and copious in its quantity. Because it is unlikely that these conditions obtain as a general rule, and even more unlikely that they obtained in early human populations, I conclude that there is little reason to believe that adaptive thinking can be used to infer the current structure of our minds from evidence of past selection pressures. (shrink)
Strong adaptationists explore complex organic design as taskspecific adaptations to ancestral environments. This strategy seems best when there is evidence of homology. Weak adaptationists don't assume that complex organic (including cognitive and linguistic) functioning necessarily or primarily represents taskspecific adaptation. This approach to cognition resembles physicists' attempts to deductively explain the most facts with fewest hypotheses. For certain domainspecific competencies (folkbiology) strong adaptationism is useful but not necessary to research. With grouplevel belief systems (religion) strong adaptationism degenerates into (...) spurious notions of social function and cultural selection. In other cases (language, especially universal grammar) weak adaptationism's 'minimalist' approach seems productive. (shrink)
Two decades ago, the eminent evolutionary biologist George C. Williams and his physician coauthor, Randolph Nesse, formulated the evolutionary medicine research program. Williams and Nesse explicitly made adaptationism a core component of the new program, which has served to undermine the program ever since, distorting its practitioners’ perceptions of evidentiary burdens and in extreme cases has served to warp practitioner’s understandings of the relationship between evolutionary benefits/detriments and medical ones. I show that the Williams and Nesse program more particularly (...) embraces the panselectionist variety of adaptationism (the empirical assumption that non-adaptive evolutionary processes are causally unimportant compared to natural selection), and argue that this has harmed the field. Panselectionism serves to conceal the enormous evidentiary hurdles that evolutionary medicine hypotheses face, making them appear stronger than they are. I use two examples of evolutionary medicine texts, on neonatal jaundice and on asthma, to show that some evolutionary medicine practitioners have allowed their fervent panselectionism to directly shape their recommendations for clinical practice. I argue that this escalation of panselectionism’s influence is inappropriate under Williams’ and Nesse original stated standards, despite being inspired by their program. I also show that the examples’ conflation of clinical and evolutionary considerations is inappropriate even under Christopher Boorse’s controversial evolution-rooted concepts of disease and health. (shrink)
The rights and wrongs of adaptationism areoften discussed by appeal to what I call theartefact model. Anti-adaptationistscomplain that the use of optimality modelling,reverse engineering and other techniques areindicative of a mistaken and outmoded beliefthat organisms are like well-designedartefacts. Adaptationists (e.g. Dennett 1995)respond with the assertion that viewingorganisms as though they were well designed isa fruitful, perhaps necessary research strategyin evolutionary biology. Anti-adaptationistsare right when they say that techniques likereverse engineering are liable to mislead. This fact does not undermine the (...) artefact modelprecisely because the same techniques misleadus for the same reasons when they are appliedunreflectively to artefacts. Thoseadaptationists who hold only that it isworthwhile to investigate organisms as thoughthey were artefacts and thoseanti-adaptationists who criticise simplisticdesign models have far more in common than thelabels attached to their positions mightsuggest. (shrink)
This contribution to the adaptationism debate elaborates the nature of constraints and their importance in evolutionary explanation and argues that the adaptationism debate should be limited to the issue of how to privilege causes in evolutionary explanation. I argue that adaptationist explanations are deeply conceptually dependent on developmental constraints, and explanations that appeal to constraints are dependant on the results of natural selection. I suggest these explanations should be integrated into the framework of historical causal explanation. Each strategy (...) explicitly appeals to some aspect of the evolutionary process, while implicitly appealing to others. Thus, adaptationists and anti-adaptationists can offer complementary causal explanations of the same explanandum. This eliminates much of the adaptationism debate and explains why its adversaries regularly agree with each other more than they would like. The adaptationism issue that remains is a species of the general issue of how to privilege causes in explanation. I show how a proposed solution to this general problem might be brought to bear on evolutionary explanations, and investigate some difficulties that might arise due to the nature of the evolutionary process. (shrink)
Elliott Sober (1987, 1993) and Orzack and Sober (forthcoming) argue that adaptationism is a very general hypothesis that can be tested by testing various particular hypotheses that invoke natural selection to explain the presence of traits in populations of organisms. In this paper, I challenge Sobers claim that adaptationism is an hypothesis and I argue that it is best viewed as a heuristic (or research strategy). Biologists would still have good reasons for employing this research strategy even if (...) it turns out that natural selection is not the most important cause of evolution. (shrink)
Godfrey-Smith ( 2001 ) has distinguished three types of adaptationism. This article builds on his analysis, and revises it in places, by distinguishing seven varieties of adaptationism. This taxonomy allows us to clarify what is at stake in debates over adaptationism, and it also helps to cement the importance of Gould and Lewontin’s ‘Spandrels’ essay. Some adaptationists have suggested that their essay does not offer any coherent alternative to the adaptationist programme: it consists only in an exhortation (...) to test adaptationist hypotheses more thoroughly than was usual in the 1970s. Here it is argued that the ‘Spandrels’ paper points towards a genuinely non-adaptationist methodology implicit in much evolutionary developmental biology. This conclusion helps to expose the links between older debates over adaptationism and more recent questions about the property of evolvability. (shrink)
Two critiques of simple adaptationism are distinguished: anti-adaptationism and extended adaptationism. Adaptationists and anti-adaptationists share the presumption that an evolutionary explanation should identify the dominant simple cause of the evolutionary outcome to be explained. A consideration of extended-adaptationist models such as coevolution, niche construction and extended phenotypes reveals the inappropriateness of this presumption in explaining the evolution of certain important kinds of features—those that play particular roles in the regulation of organic processes, especially behavior. These biological or (...) behavioral ‘levers’ are distinctively available for adaptation and exaptation by their possessors and for co-optation by other organisms. As a result they are likely to result from a distinctive and complex type of evolutionary process that conforms neither to simple adaptationist nor to anti-adaptationist styles of explanation. Many of the human features whose evolutionary explanation is most controversial belong to this category, including the female orgasm. (shrink)
The so-called "adaptationism" of mainstream evolutionary biology has been criticized from a variety of sources. One, which has received relatively little philosophical attention, is developmental biology. Developmental constraints are said to be neglected by adaptationists. This paper explores the divergent methodological and explanatory interests that separate mainstream evolutionary biology from its embryological and developmental critics. It will focus on the concept of constraint itself; even this central concept is understood differently by the two sides of the dispute.
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. (shrink)
Debates over adaptationism can be clarified and partially resolved by careful consideration of the ‘grain’ at which evolutionary processes are described. The framework of ‘adaptive landscapes’ can be used to illustrate and facilitate this investigation. We argue that natural selection may have special status at an intermediate grain of analysis of evolutionary processes. The cases of sickle-cell disease and genomic imprinting are used as case studies.
Andrews et al. effectively argue that, despite prominent criticism, adaptationism can be a viable research strategy. We agree. In our complementary commentary, we discuss the neglected method of inference to the best explanation and argue that it is a valuable addition to the adaptationist's methodological practice.
In this paper, I will take advantage of the controversy on the legitimacy of adaptationism in evolutionary biology to further investigate the nature of adaptationistic thinking, or biological explanations in general. To this end, first I will look at the famous and provocative criticism made by Gould and Lewontin (1979) against then-prevalent adaptationism --- a research strategy for accounting for the origin of traits of organisms seemingly adapted to the environment by appealing primarily to natural selection. Then I (...) will consider its counterarguments put forward by Dennett (1995), one of the proponents of adaptationism, in order toscrutinize the intrinsically hypothetical character of adaptationistic thinking. By amplifying Dennett’s points, I will finally reach the conclusion that there are two senses --- objective and subjective --- in which adaptationistic thinking is said to be hypothetical, which nonetheless do not prevent it from qualifying as scientific practice. In the process, I will also gain an insight into the sense in which the theory of natural selection is said to be mechanistic, as a spin-off. (shrink)
In our target article, we discussed the standards of evidence that could be used to identify adaptations, and argued that building an empirical case that certain features of a trait are best explained by exaptation, spandrel, or constraint requires the consideration, testing, and rejection of adaptationist hypotheses. We are grateful to the 31 commentators for their thoughtful insights. They raised important issues, including the meaning of “exaptation”; whether Gould and Lewontin's critique of adaptationism was primarily epistemological or ontological; the (...) necessity, sufficiency, or utility of design evidence, phylogenetic analyses, homology, and molecular genetics in distinguishing exaptations from adaptations; whether adaptationists accept adaptationist hypotheses too quickly; and the real utility of adaptationism to human behavioral science. We organize our response along the major points of the target article, in some situations defending our original claims and in others modifying them. While debate on these issues will undoubtedly continue, we are cautiously optimistic that the main points of the target article (as modified by our response) will help move the debate in a positive direction. (shrink)
It is often thought that if an adaptationist explanation of some behavioural phenomenon is true, then this fact shows that a culturist explanation of the very same phenomenon is false, or else the adaptationist explanation preempts or crowds out the culturist explanation in some way. This chapter shows why this so-called competition thesis is misguided. Two evolutionary models are identified — the Information Learning Model and the Strategic Learning Model — which show that adaptationist reasoning can help explain why cultural (...) learning evolved. These models suggest that there will typically be a division of labor between adaptationist and culturist explanations. It is then shown that the Strategic Learning Model, which has been widely neglected by adaptationist thinkers, has important and underappreciated implications for a question that has long been contentious in the behavioural sciences — the question of the malleability of human nature. (shrink)
In recent times evolutionary psychologists have offered adaptation explanations for a wide range of human psychological characteristics. Critics, however, have argued that such endeavors are problematic because the appropriate evidence required to demonstrate adaptation is unlikely to be forthcoming, therefore severely limiting the role of the adaptationist program in psychology. More specifically, doubts have been raised over both the methodology employed by evolutionary psychologists for studying adaptations and about the possibility of ever developing acceptably rigorous evolutionary explanations of human psychological (...) phenomena. We argue that by employing a wide range of methods for inferring adaptation and by adopting an inference to the best explanation strategy for evaluating adaptation explanations, these two doubts can be adequately addressed. We illustrate how this approach can be fruitfully employed in evaluating claims about the evolutionary origins of language, and conclude with a brief discussion of the future of evolutionary psychology. (shrink)
1 Adaptationism is a research strategy that seeks to identify adaptations and the specific selective forces that drove their evolution in past environments. Since the mid-1970s, paleontologist Stephen J. Gould and geneticist Richard Lewontin have been critical of adaptationism, especially as applied toward understanding human behavior and cognition. Perhaps the most prominent criticism they made was that adaptationist explanations were analogous to Rudyard Kipling's Just So Stories (outlandish explanations for questions such as how the elephant got its trunk). (...) Since storytelling (through the generation of hypotheses and the making of inferences) is an inherent part of science, the criticism refers to the acceptance of stories without sufficient empirical evidence. In particular, Gould, Lewontin, and their colleagues argue that adaptationists often use inappropriate evidentiary standards for identifying adaptations and their functions, and that they often fail to consider alternative hypotheses to adaptation. Playing prominently in both of these criticisms are the concepts of constraint, spandrel, and exaptation. In this article we discuss the standards of evidence that could be used to identify adaptations and when and how they may be appropriately used. Moreover, building an empirical case that certain features of a trait are best explained by exaptation, spandrel, or constraint requires demonstrating that the trait's features cannot be better accounted for by adaptationist hypotheses. Thus, we argue that the testing of alternatives requires the consideration, testing, and systematic rejection of adaptationist hypotheses. Where possible, we illustrate our points with examples taken from human behavior and cognition. Key Words: adaptation; ADHD; brain allometry; constraint; epistemology; evolutionary psychology; exaptation; female orgasm; optimization; special design; waist-hip ratio (WHR). Footnotes1 The authors contributed equally to this paper. Order of authorship was determined alphabetically. Correspondence may be addressed to any of the authors. (shrink)
Attempts to explain human behavior that appeal to economic rationality share many of the same ontological as- sumptions and methodological practices that the so-called ‘adaptationist program’ in biology was criticized for. This program in biology was largely abandoned by biologists as poorly motivated, and replaced with the active testing of both adaptive and non-adaptive hypotheses regarding the spread and maintenance of traits in populations. This development was largely welcome by the biological <span class='Hi'>community</span>, despite having required the development of new (...) tools, both conceptual and method- ological. Many analysts of contemporary microeconomic practice criticize the assumptions and practices employed therein as similarly poorly motivated. Close attention to these criticisms reveal them to have more than superficial similarities to the critiques of adaptationism in biology. These similarities extend to some macroeconomics researchers recent suggestions of ways that hypotheses regarding the causes of people’s actions might be tested; as yet, however, these suggestions have not been embraced by the field as a whole. By attending to the ways in which biological practice has moved beyond the adaptationist program, similar changes in economic practice may be motivated. (shrink)
We describe delusional disorder–jealous type (“morbid jealousy”) with the adaptationist perspective used by Darwinian psychiatrists and evolutionary psychologists to explain the relatively common existence and continued prevalence of mental disorders. We then apply the “harmful dysfunction” analysis to morbid jealousy, including a discussion of this disorder as (1) an end on a continuum of normal jealousy or (2) a discrete entity. (Published Online November 9 2006).
The target article shows that the application of the evolutionary theory to psychopathology should not necessarily consist in finding hidden adaptive benefits for each psychiatric syndrome. However, in rejecting lax adaptationism, Darwinian psychiatrists should not forget that the search for adaptive behavioral polymorphisms can be a powerful antidote against the normative attitude of mainstream psychiatry and its growing tendency to medicalize human diversity. (Published Online November 9 2006).
Methodological analysis shows that the concepts of fitness and adaptation are more complex than the literature suggests. Various arguments against adaptationism are inadequate since they are couched in terms of unduly simplistic notions.
Strong adaptationists would explain complex organic designs as specific adaptations to particular ancestral environments. Weak adaptationists don't assume that complex organic functioning represents evolutionary design in the sense of niche-specific adaptation. For some domain-specific competencies (folkbiology) strong adaptationism is useful, not necessary. With group-level belief systems (religion), strong adaptationism can become spurious pseudo-adaptationism. In other cases (language), weak adaptationism proves productive.
Andrews et al. present a form of instrumental adaptationism that is designed to test the hypothesis that a given trait is an adaptation. This epistemological commitment aims to make clear statements about behavioural natural kinds. The instrumental logic is sound, but it is the limits of our empirical imagination that can cause problems for theory construction.
Rather than starting with traits and speculating whether selective forces drove evolution in past environments, we propose starting with a candidate gene associated with a trait and testing first for patterns of selection at the DNA level. This can provide limitations on the number of traits to be evaluated subsequently by adaptationism as described by Andrews et al.
The adaptationist framework is necessary and sufficient for unifying the social and natural sciences. Gintis's “beliefs, preferences, and constraints” (BPC) model compares unfavorably to this framework because it lacks criteria for determining special design, incorrectly assumes that standard evolutionary theory predicts individual rationality maximisation, does not adequately recognize the impact of psychological mechanisms on culture, and is mute on the behavioural implications of intragenomic conflict. (Published Online April 27 2007).
In Chapter Five of The Mind Doesn’t Work That Way, Jerry Fodor argues that since it is likely that human minds evolved quickly as saltations rather than gradually as the product of an accumulation of small mutations, evolutionary psychologists are wrong to think that human minds are adaptations. I argue that Fodor’s requirement that adaptationism entails gradualism is wrongheaded. So, while evolutionary psychologists may be wrong to endorse gradualism—and I argue that they are wrong—it does not follow that they (...) are wrong to endorse an adaptationist explanation for how the human mind evolved. (shrink)
In the current dialogue of “science and religion,” it is widely assumed that the thoughts of Darwinists and that of atheists overlap. However, Jerry Fodor, a full-fledged atheist, recently announced a war against Darwinism with his atheistic campaign. Prima facie, this “civil war” might offer a chance for theists: If Fodor is right, Darwinistic atheism will lose the cover of Darwinism and become less tenable. This paper provides a more pessimistic evaluation of the situation by explaining the following: Fodor’s criticism (...) of adaptationism (as the backbone of Darwinism), viz., his refutation of any counterfactual-supporting laws on the macro-evolutionary level, implies that a law-maker is dispensable on this level. This will either encourage skepticism against the omniscience (at least that concerning the future of macro-evolution) of the Creator, or render the notion of God less appealing. (shrink)
I consider some hitherto unexplored examples of teleological language in the sciences. In explicating these examples, I aim to show (a) that such language is not the sole preserve of the biological sciences, and (b) that not all such talk is reducible to the ascription of functions. In chemistry and biochemistry, scientists explaining molecular rearrangements and protein folding talk informally of molecules rearranging “in order to” maximize stability. Evolutionary biologists, meanwhile, often speak of traits evolving “in order to” optimize some (...) fitness-relevant variable. I argue that in all three contexts such locutions are best interpreted as shorthands for more detailed explanations which, were we to spell them out in full, would show that the relevant process would robustly converge towards the same end-point despite variation in initial conditions. This suggests that, in biology, such talk presupposes a substantial form of adaptationism. The upshot is that such shorthands may be more applicable in the physical sciences than the biological. (shrink)
This paper offers an evolutionary account of chronic pain. Chronic pain is a maladaptive by-product of pain mechanisms and neural plasticity, both of which are highly adaptive. This account shows how evolutionary psychology can be integrated with Flanagan's natural method, and in a way that avoids the usual charges of panglossian adaptationism and an uncritical commitment to a modular picture of the mind. Evolutionary psychology is most promising when it adopts a bottom-up research strategy that focuses on basic affective (...) and motivational systems (as opposed to higher cognitive functions) that are phylogenetically deep. (shrink)
In his recent book on Darwinism, Daniel Dennett has offered up a species of a priori selectionism that he calls algorithmic. He used this view to challenge a number of positions advocated by Stephen J. Gould. I examine his algorithmic conception, review his unqualified enthusiasm for the a priori selectionist position, challenge Dennett's main metaphors (cranes vs. skyhooks and a design space), examine ways in which his position has lead him to misunderstand or misrepresent Gould (spandrels, exaptation, punctuated equilibrium, contingency (...) and disparity), and discuss recent results in developmental biology that suggest that an a priori position does not fill the demands of an evolutionary biology. I conclude by insisting that evolutionary biology is many leveled, complicated, and is carried on an ever shifting and expanding empirical base that when disregarded results in caricature. (shrink)
The ontological dependence of one domain on another is compatible with the explanatory autonomy of the less basic domain. That autonomy results from the fact that the relationship between two domains can be very complex. In this paper I distinguish two different types of complexity, two ways the relationship between domains can fail to be transparent, both of which are relevant to evolutionary biology. Sometimes high level explanations preserve a certain type of causal or counterfactual information which would be lost (...) at the lower level; I argue that this is central to the proper understanding of the adaptationist program. Sometimes high level kinds are multiply realised by lower level kinds: I argue that this is central to the understanding of macroevolution. (shrink)
Unified explanations seek to situate the traits of human beings in a causal framework that also explains the trait values found in nonhuman species. Disunified explanations claim that the traits of human beings are due to causal processes not at work in the rest of nature. This paper outlines a methodology for testing hypotheses of these two types. Implications are drawn concerning evolutionary psychology, adaptationism, and anti-adaptationism.
In a recent paper, Potochnik (Biol Philos 24(2):183–197, 2009) analyses some uses of optimality modelling in light of the anti-adaptationism criticism. She distinguishes two broad classes of such uses (weak and strong) on the basis of assumptions held by biologists about the role and the importance of natural selection. This is an interesting proposal that could help in the epistemological characterisation of some biological practices. However, Potochnik’s distinction also rests on the assumption that all optimality modelling represent the selection (...) dynamic involved in the system of phenomena being considered. Since this assumption does not hold for models belonging to optimal foraging theory (OFT)—one of behavioural ecology’s important modelling traditions—Potochnik’s proposal has to be critically reappraised. In this paper, we briefly discuss what is optimality modelling and what it means for a model to represent a dynamic of selection or of evolution. Then, we demonstrate that OFT modelling is unable to represent either past or contemporary selection dynamics. In order to make this point, we carefully delineate the theory’s rationale. This allows us to identify and analyse the assumptions on which the theory is built, and to circumscribe precisely the role that natural selection plays in it. Next, we show that the distinction of weak and strong uses of optimality modelling is seriously weakened when OFT modelling is taken into account. More precisely, the distinction is either irrelevant (if the assumption that selection dynamics are represented in all optimality modelling is held) or of a modest utility (if the assumption is dropped). However, we suggest that Potochnik’s original proposal could be saved, and that it even constitutes a tool to appraise the marks left in the literature by the evolution of optimality modelling practices in the last four decades, provided that it is made into a tripartite distinction. (shrink)
Gould's Structure ofEvolutionary Theory argues that Darwinism hasundergone significant revision. Although Gouldsucceeds in showing that hierarchicalapproaches have expanded Darwinism, hiscritique of adaptationism is less successful. Gould claims that the ubiquity of developmentalconstraints and spandrels has forced biologiststo soften their commitment to adaptationism. Iargue that Gould overstates his conclusion; hisprincipal claims are compatible with at leastsome versions of adaptationism. Despite thisweakness, Gould's discussion of adaptationism –particularly his discussions of the exaptivepool and cross-level spandrels – shouldprovoke new work (...) in evolutionary theory and thephilosophy of biology. (shrink)
This response (a) integrates non-equilibrium evolutionary genetic models, such as coevolutionary arms-races and recent selective sweeps, into a framework for understanding common, harmful, heritable mental disorders; (b) discusses the forms of ancestral neutrality or balancing selection that may explain some portion of mental disorder risk; and (c) emphasizes that normally functioning psychological adaptations work against a backdrop of mutational and environmental noise. (Published Online November 9 2006).
Recent work on the heat-shock protein Hsp90 by Rutherford and Lindquist (1998) has been included among the pieces of evidence taken to show the essential role of developmental processes in evolution; Hsp90 acts as a buffer against phenotypic variation, allowing genotypic variation to build. When the buffering capacity of Hsp90 is altered (e.g., in nature, by mutation or environmental stress), the genetic variation is "revealed," manifesting itself as phenotypic variation. This phenomenon raises questions about the genetic variation before and after (...) what I will call a "revelation event": Is it neutral, nearly neutral, or non-neutral (i.e., strongly deleterious or strongly advantageous)? Moreover, what kinds of evolutionary processes do we take to be at work? Rutherford and Lindquist (1998) focus on the implications of non-neutral variation and selection. Later work by Queitsch, Sangster, and Lindquist (2002) and Sangster, Lindquist, and Queitsch (2004) raises the possibility that Hsp90 buffering may play the role that was played by drift in Sewall Wright's shifting balance model, permitting transition from one adaptive peak to another. However, Ohta (2002) suggests that much of this variation may be nearly neutral, which in turn, would imply a strong role for drift as well as selection. The primary goal of this paper is to illuminate the alternative scenarios and the processes operating in each. At the end, I raise the possibility of a synthesis between evo-devo and nearly neutral evolution. (shrink)
The “straw man” prior expectation of the dominant social psychology paradigm is that humans should behave with perfect rationality and high ethical standards. The more modest claim of evolutionary psychologists is that humans have evolved specific adaptations for adaptive problems that were reliably present in the ancestral environment. Outside that restricted range of problems, one should not expect optimal behavior.
To understand adaptation (and exaptation), a more comprehensive view of development is required: one beyond a constraining force. Developmental plasticity may be an adaptation by natural selection simultaneously favored (or sometimes in conflict) at multiple levels of biological organization (e.g., cells, individuals, groups, etc.). To understand the interrelationships between developmental plasticity and adaptive evolution I borrow heavily from West-Eberhard (2003) and Frank (1995; 1997). Developmental plasticity facilitates evolution, results in particular patterns of evolutionary change, and may produce exaptations by design (...) rather than by chance. (shrink)
The evolutionary theory of sex implies a theoretically principled account of the causal mechanisms underlying personality systems in which males pursue a relatively high-risk strategy compared to females and are thus higher on traits linked to sensation seeking and social dominance. Females are expected to be lower on these traits but higher on traits related to nurturance and attraction to long-term relationships. The data confirm this pattern of sex differences. It is thus likely that these traits have (...) been a focus of natural selection rather than the traits of gregarious/aloof and arrogant/unassuming hypothesized by Depue & Collins. (shrink)
The proposal that there are specific adaptations for the expression and detection of pain appears premature on both conceptual and empirical grounds. We discuss criteria for the validation of a pain facial expression. We also describe recent findings from our lab on coping styles and pain expression, which illustrate the importance of considering individual differences when proposing evolutionary explanations.