A scientific explanatory project, part-whole explanation, and a kind of science, part-whole science are premised on identifying, investigating, and using parts and wholes. In the biological sciences, mechanistic, structuralist, and historical explanations are part-whole explanations. Each expresses different norms, explananda, and aims. Each is associated with a distinct partitioning frame for abstracting kinds of parts. These three explanatory projects can be complemented in order to provide an integrative vision of the whole system, as is shown for a detailed case study: (...) the tetrapod limb. My diagnosis of part-whole explanation in the biological sciences as well as in other domains exploring evolved, complex, and integrated systems (e.g., psychology and cognitive science) cross-cuts standard philosophical categories of explanation: causal explanation and explanation as unification. Part-whole explanation is itself one essential aspect of part-whole science. (shrink)

The dangers of character reification for cladistic inference are explored. The identification and analysis of characters always involves theory-laden abstraction—there is no theory-free “view from nowhere.” Given theory-ladenness, and given a real world with actual objects and processes, how can we separate robustly real biological characters from uncritically reified characters? One way to avoid reification is through the employment of objectivity criteria that give us good methods for identifying robust primary homology statements. I identify six such criteria and explore each (...) with examples. Ultimately, it is important to minimize character reification, because poor character analysis leads to dismal cladograms, even when proper phylogenetic analysis is employed. Given the deep and systemic problems associated with character reification, it is ironic that philosophers have focused almost entirely on phylogenetic analysis and neglected character analysis. (shrink)

Despite the amount of work that has been produced on the subject over the years, the ‘transformation of cladistics’ is still a misunderstood episode in the history of comparative biology. Here, I analyze two outstanding, highly contrasting historiographic accounts on the matter, under the perspective of an influential dichotomy in the philosophy of science: the opposition between Scientific Realism and Empiricism. Placing special emphasis on the notion of ‘causal grounding’ of morphological characters in modern developmental biology’s theories, I arrive at (...) the conclusion that a ‘new transformation of cladistics’ is philosophically plausible. This ‘reformed’ understanding of ‘pattern cladistics’ entails retaining the interpretation of cladograms as ‘schemes of synapomorphies’, but in association to construing cladogram nodes as ‘developmental-genetic taxic homologies’, instead of ‘standard Darwinian ancestors’. The reinterpretation of pattern cladistics presented here additionally proposes to take Bas Van Fraassen’s ‘constructive empiricism’ as a philosophical stance that could properly support such analysis of developmental-genetic data for systematic purposes. The latter suggestion is justified through a reappraisal of previous ideas developed by prominent pattern cladists , which concerned a scientifically efficient ‘observable/non-observable distinction’ linked to the conceptual pair ‘ontogeny and phylogeny’. Finally, I argue that a robust articulation of Antirealist alternatives in systematics may provide a rational basis for its disciplinary separation from evolutionary biology, as well as for a critical reconsideration of the proper role of certain Scientific Realist positions, currently popular in comparative biology. (shrink)

Phylogenetics is the study and reconstruction of evolutionary history and is filled with numerous foundational issues of interest to philosophers. This paper briefly introduces some central concepts in the field, describes some of the main methods for inferring phylogenies, and provides some arguments for the superiority of model-based methods such as Likelihood and Bayesian methods over nonparametric methods such as parsimony. It also raises some underdeveloped issues in the field of interest to philosophers.

The use of molecules and reactions as evidence, markers and/or traits for evolutionary processes has a history more than a century long. Molecules have been used in studies of intra-specific variation and studies of similarity among species that do not necessarily result in the analysis of phylogenetic relations. Promoters of the use of molecular data have sustained the need for quantification as the main argument to make use of them. Moreover, quantification has allowed intensive statistical analysis, as a condition and (...) a product of increasing automation. All of these analyses are subject to the methodological anxiety characteristic of a community in search of objectivity. It is in this context that scientists compared and evaluated protein and nucleic acid sequence data with other types of molecular data – including immunological, electrophoretic and hybridization data. This paper argues that by looking at long-term historical processes, such as the use of molecular evidence in evolutionary biology, we gain valuable insights into the history of science. In that sense, it accompanies a growing concern among historians for big-pictures of science that incorporate the fruitful historical research on local cases of the last decades. (shrink)

In this article, I examine the issue of the alleged circularity in the determination of homologies within cladistic analysis. More specifically, I focus on the claims made by the proponents of the dynamic homology approach, regarding the distinction (sometimes made in the literature) between primary and secondary homology. This distinction is sometimes invoked to dissolve the circularity issue, by upholding that characters in a cladistic data matrix have to be only primarily homologous, and thus can be determined independently of phylogenetic (...) hypotheses, by using the classical Owenian criteria (for morphological characters) or via multiple sequence alignment (for sequence data). However, since in the dynamic approach, sequence data can be analyzed without being pre-aligned, proponents have claimed that the distinction between primary and secondary homology has no place within cladistics. I will argue that this is not the case, since cladistic practice within the dynamic framework does presuppose primary homology statements at a higher level. (shrink)

Taking its clues from Popperian philosophy of science, cladistics adopted a number of assumptions of the empiricist tradition. These include the identification of a dichotomy between observation reports and theoretical statements and its subsequent abandonment on the basis of the insight that all observation reports are theory-laden. The neglect of the ‘context of discovery’, which is the step of theory (hypothesis) generation. The emphasis on coherentism in the ‘context of justification’, which is the step of evaluation of the relative merits (...) of alternative theories. The appeal to a total evidence approach in phylogenetic inference. And finally, a silence about causation, which results in an instrumentalist approach to phylogeny reconstruction. This paper explores how these empiricist assumptions are embedded in phylogenetic systematics, and why these assumptions are problematic for cladists (or any taxonomists). (shrink)

The term “cladist” has distinct meanings in distinct contexts. Communication between philosophers, historians, and biologists has been hindered by different understandings of the term in various contexts. In this paper I trace historical and conceptual connections between several broadly distinct senses of the term “cladist”. I propose seven specific definitions that capture distinct contemporary uses. This serves to disambiguate some cases where the meaning is unclear, and will help resolve apparent disagreements that in fact result from conflicting understandings of the (...) term. (shrink)

We analyze the relationship between evolutionary theory and classification of higher taxa in the work of three ichthyologists: Albert C.L.G. Günther (1830–1914), Edward Drinker Cope (1840–1897), and Theodore Gill (1837–1914). The progress of ichthyology in the early years following the Origin has received little attention from historians, and offers an opportunity to further evaluate the extent to which evolutionary theorizing influenced published views on systematic methodology. These three ichthyologists held radically different theoretical views. The apparent commensurability of claims about relationships (...) among groups of fishes belies differences in what the relationships actually were supposed to be. As well, interpreting classification as genealogical did not lead to agreement about taxonomic methodology; instead, applying evolutionary theory raised new axes of disagreement. (shrink)

I respond to the bad lot argument in the context of biological systematics. The response relies on the historical nature of biological systematics and on the availability of pattern explanations. The basic assumption of common descent enables systematic methodology to naturally generate candidate explanatory hypotheses. However, systematists face a related challenge in the issue of character analysis. Character analysis is the central problem for contemporary systematics, yet the general problem of which it is a case—what counts as evidence?—has not been (...) adequately discussed by proponents of inference to the best explanation. Facing this problem is the price of adopting abductive methods. I sketch an account of how systematists approach the problem of evidence. (shrink)

Havstad and Smith (2019) argue that Lakatos’ “methodology of scientific research programs” (MSRP) is a promising philosophical framework for explaining the perceived empirical success of the hypothesis that birds are maniraptoran theropod dinosaurs, and the perceived empirical failures or stagnation of alternatives to that hypothesis. These conclusions are rejected: Havstad and Smith’s account of the alternative “research programs” inadequately characterizes criticism of the hypothesis that birds are maniraptoran theropods and they neither offer sufficient modifications to MSRP to correct its known (...) difficulties in deriving logically or empirically satisfactory criteria for the assessment and preferential selection of “research programs” from historiographical data, nor proposals to mitigate its tendency to promote confirmation bias and dogmatism. Independent flight loss, an important problem in systematic ornithology with implications for the origin of birds, provides a supplementary demonstration of how the application of MSRP in the present context would tend systematically to mislead investigations of the evolutionary history of birds by promoting an uncritical perspective. Given these difficulties, MSRP is an unacceptable philosophical framework for evaluating alternative hypotheses for the origin of birds. (shrink)

The metaphysical nature of homologies has been variously characterized as natural kind, individualist, and pluralist-pragmatic. In this essay, I aim to build on the work of proponents of a natural kinds ontology for homologies using Richard Boyd’s influential HPC account of natural kinds. I aim to advance this position by showing the unique fit of extending the HPC account to homologies, deflecting individualist critiques, as well as the pluralist-pragmatic alternative, showing that homologies have a determinate metaphysical character as kinds. As (...) an important extension of this position, I attempt to explain away how the mistaken metaphysics of the individualist, and derivatively the pluralist-pragmatic approach that contextually embraces it, can facilitate certain elements of biological practice. (shrink)

This article, which is intended both as a position paper in the philosophical debate on natural kinds and as the guest editorial to this thematic issue, takes up the challenge posed by Ian Hacking in his paper, “Natural Kinds: Rosy Dawn, Scholastic Twilight.” Whereas a straightforward interpretation of that paper suggests that according to Hacking the concept of natural kinds should be abandoned, both in the philosophy of science and in philosophy more generally, we suggest that an alternative and less (...) fatalistic reading is also possible. We argue that abandoning the concept of natural kinds would be premature, as it still can do important work. Our concern is with the situation in the (philosophy of the) life sciences. Against the background of this concern we attempt to set something of an agenda for future research on the topic of natural kinds in the (philosophy of the) life sciences. (shrink)

The aim of this article is to detail some reservations against the beliefs, claims, or presuppositions that current essentialist natural kind concepts (including homeostatic property cluster kinds) model grouping practices in the life sciences accurately and generally. Such concepts fit reasoning into particular preconceived epistemic and semantic patterns. The ability of these patterns to fit scientific practice is often argued in support of homeostatic property cluster accounts, yet there are reasons to think that in the life sciences kind concepts exhibit (...) a diversity of grouping practices that are flattened out by conceptualizing them as natural kinds. Instead this article argues that the process of understanding grouping practices needs to start from a more neutral position independent of any ontological account. Following Love (Acta Biotheor 57:51–75, 2009) this paper suggests that typical natural kind concepts should be broached in the first place as grouping strategies that use a variety of semantic and epistemic tactics to apply group-bound information to tasks of explanation and understanding. (shrink)

Many of the current comparisons of taxic phylogenetic and biological homology in the context of morphology focus on what are seen as categorical distinctions between the two concepts. The first, it is claimed, identifies historical patterns of conservation and variation relating taxa; the second provides a causal framework for the explanation of this conservation and variation. This leads to the conclusion that the two need not be placed in conflict and are in fact compatible, having non-competing epistemic purposes or mapping (...) the same extensions in the form of monophyletic groupings (see Roth, The biological basis of homology 1–26, 1988; Sluys, J Zool Syst Evol Res 34:145–152, 1996; Abouheif, Trends Ecol Evol 12:405–408, 1997; Brigandt, J Exp Zool 299:9–17, 2003, Biol Philos 22:709–725, 2007; Assis and Brigandt, Evol Biol 36:248–255, 2009). This article argues that moves in this direction miss the essential disagreement between these concepts as they have been developed in the context of the debate concerning the best concept for evolutionary investigation. We should rather see these concepts employing a common fundamental methodological approach to homology, but disagreeing about how to apply the methodology effectively. Both concepts employ class reasoning, which pursues homologies as units of generalization—more precisely, as sources of reliable and relevant group-bound information in the form of shared underlying causes. The dispute can be better understood by two poles that structure such reasoning: the need for a reliable basis for projections about the causal history of shared structures, and the desire to identify homologous characters with more informative and specific causal information relevant to generalizing about evolutionary processes. Judgments in favor of one or the other in turn have affected the scope or extension of these competing homology concepts. (shrink)

The goal of this paper is to encourage a reconfiguration of the discussion about typology in biology away from the metaphysics of essentialism and toward the epistemology of classifying natural phenomena for the purposes of empirical inquiry. First, I briefly review arguments concerning ‘typological thinking’, essentialism, species, and natural kinds, highlighting their predominantly metaphysical nature. Second, I use a distinction between the aims, strategies, and tactics of science to suggest how a shift from metaphysics to epistemology might be accomplished. Typological (...) thinking can be understood as a scientific tactic that involves representing natural phenomena using idealizations and approximations, which facilitates explanation, investigation, and theorizing via abstraction and generalization. Third, a variety of typologies from different areas of biology are introduced to emphasize the diversity of this representational reasoning. One particular example is used to examine how there can be epistemological conflict between typology and evolutionary analysis. This demonstrates that alternative strategies of typological thinking arise due to the divergent explanatory goals of researchers working in different disciplines with disparate methodologies. I conclude with several research questions that emerge from an epistemological reconfiguration of typology. (shrink)

Most cognitive scientists nowadays tend to think that at least some of the mind’s capacities are the product of biological evolution, yet important conceptual problems remain for all scientists in order to be able to speak coherently of mental or cognitive systems as having evolved naturally. Two of these important problems concern the articulation of adequate, interesting, and empirically useful concepts of homology and variation as applied to cognitive systems. However, systems in cognitive science are usually understood as functional systems (...) of some sort. Thus, to be able to talk about functional systems being homologous requires having a solid, adequate, and empirically articulated concept of functional homology—and the same is true about functional variation. Here I construct an original concept of functional homology that, in my view, adequately systematizes a number of actual uses of the word “functional homology” in a variety of biological disciplines and in ethology. I also propose a number of criteria for the empirical application of the concept that are analogous to the criteria that are currently used in comparative biology, ethology, and molecular developmental genetics. Then I construct a concept of functional variation on the basis of this concept of homology. (shrink)

There is an argument that has recently been deployed in favor of thinking that the mind is mostly (or even exclusively) composed of cognitive modules; an argument that draws from some ideas and concepts of evolutionary and of developmental biology. In a nutshell, the argument concludes that a mind that is massively composed of cognitive mechanisms that are cognitively modular (henceforth, c-modular) is more evolvable than a mind that is not c-modular (or that is scarcely c-modular), since a cognitive mechanism (...) that is c-modular is likely to be biologically modular (henceforth, b-modular), and b-modular characters are more evolvable (e.g., Sperber 2002, Carruthers 2005). In evolutionary biology, the evolvability of a character in an organism is understood as the “organism’s capacity to facilitate the generation of non-lethal selectable phenotypic variation from random mutation” with respect to that character. Here I will argue that the notion of cognitive modularity needed to make this argument plausible will have to be understood in terms of the biological notion of variational independence; that is, it will have to be understood in such a way that a cognitive feature is c-modular only if few or no other morphological changes (cognitive and not) are significantly correlated with variations of that feature arising in members of the relevant population. I will also argue that all –except for (possibly) one—of the connotations contained in a cluster of notions of cognitive modularity widely accepted in some of the mainstream currents of thought in classical cognitive science, are simply irrelevant to the argument. In order to argue for this, I will have to examine the question as to whether there are any strong theoretical connections between (1) those connotations and (2) notions of modularity accepted in biology, specially in evolutionary and in developmental biology, that are thought to be most relevant to arguments to the effect that biological modularity enhances evolvability. (shrink)

Despite the promises made by molecular evolutionists since the early 1960s that phylogenies would be readily reconstructed using molecular data, the construction of molecular phylogenies has both retained many methodological problems of the past and brought up new ones of considerable epistemic relevance. The field is driven not only by changes in knowledge about the processes of molecular evolution, but also by an ever-present methodological anxiety manifested in the constant search for an increased objectivity—or in its converse, the avoidance of (...) subjectivity.This paper offers an exhaustive account of the methodological and conceptual difficulties embedded in each of the steps required to elaborate molecular phytogenies. The authors adopt a historical perspective on the field in order to follow the development of practices that seek to increase the objectivity of their methods and representations. These include the adoption and development of explicit criteria for evaluation of evidence, and of procedures associated with methods of statistical inference, quantification and automation. All these are linked to an increasing use of computers in research since the mid 1960s. We will show that the practices of objectivity described are highly dependent on the problems and tools of molecular phylogenetics. (shrink)

Essentialism is widely regarded as a mistaken view of biological kinds, such as species. After recounting why (sections 2-3), we provide a brief survey of the chief responses to the “death of essentialism” in the philosophy of biology (section 4). We then develop one of these responses, the claim that biological kinds are homeostatic property clusters (sections 5-6) illustrating this view with several novel examples (section 7). Although this view was first expressed 20 years ago, and has received recent discussion (...) and critique, it remains underdeveloped and is often misrepresented by its critics (section 8). (shrink)

Despite the traditional focus on metaphysical issues in discussions of natural kinds in biology, epistemological considerations are at least as important. By revisiting the debate as to whether taxa are kinds or individuals, I argue that both accounts are metaphysically compatible, but that one or the other approach can be pragmatically preferable depending on the epistemic context. Recent objections against construing species as homeostatic property cluster kinds are also addressed. The second part of the paper broadens the perspective by considering (...) homologues as another example of natural kinds, comparing them with analogues as functionally defined kinds. Given that there are various types of natural kinds, I discuss the different theoretical purposes served by diverse kind concepts, suggesting that there is no clear-cut distinction between natural kinds and other kinds, such as functional kinds. Rather than attempting to offer a unique metaphysical account of ‘natural’ kind, a more fruitful approach consists in the epistemological study of how different natural kind concepts are employed in scientific reasoning. (shrink)

Several authors have argued that higher taxa are monophyletic homeostatic property cluster natural kinds. On the traditional definition of monophyly, this will not work: the emergence of taxon-defining homeostatic property clusters would not always correspond to unique speciation events. An alternative conception of monophyly is developed and advocated, which can accommodate the homeostatic property cluster proposal. Recent work in philosophy of science shows that it meets appropriate standards of objectivity and precision.