Many moral philosophers accept the Debunking Thesis, according to which facts about natural selection provide debunking explanations for certain of our moral beliefs. I argue that philosophers who accept the Debunking Thesis beg important questions in the philosophy of biology. They assume that past selection can explain why you or I hold certain of the moral beliefs we do. A position advanced by many prominent philosophers of biology implies that this assumption is false. According to the Negative View, natural selection (...) cannot explain the traits of individuals. Hence, facts about past selection cannot provide debunking explanations for any of our moral beliefs. The aim of this paper is to explore the conflict between the Debunking Thesis and the Negative View. (shrink)

In this article we argue that the classical—linear and bottom-up directed—models of causation in biology, and the ‘‘proximate/ultimate’’ dichotomy, are inappropriate to capture the complexity inherent to biological processes. We introduce a new notion of ‘‘multilevel causation’’ where old dichotomies such as proximate/ultimate and bottom-up/ top-down are reinterpreted within a multilevel, web-like, approach. In briefly reviewing some recent work on complexity, EvoDevo, carcinogenesis, autocatalysis, comparative genomics, animal regeneration, phenotypic plasticity, and niche construction, we will argue that such reinterpretation is a (...) necessary step for the advancement of the ‘‘Extended Synthesis.’’. (shrink)

The purpose of this paper is to defend, contra Fodor and Piattelli-Palmarini (F&PP), that the theory of natural selection (NS) is a perfectly bona fide empirical unified explanatory theory. F&PP claim there is nothing non-truistic, counterfactual-supporting, of an “adaptive” character and common to different explanations of trait evolution. In his debate with Fodor, and in other works, Sober defends NS but claims that, compared with classical mechanics (CM) and other standard theories, NS is peculiar in that its explanatory models are (...) a priori (a trait shared with few other theories). We argue that NS provides perfectly bona fide adaptive explanations of phenotype evolution, unified by a common natural-selection guiding principle. First, we introduce the debate and reply to F&PP’s main argument against NS. Then, by reviewing different examples and analyzing Fisher’s model in detail, we show that NS explanations of phenotypic evolution share a General Natural Selection Principle. Third, by elaborating an analogy with CM, we argue against F&PP’s claim that such a principle would be a mere truism and thus explanatorily useless, and against Sober’s thesis that NS models/explanations have a priori components that are not present in CM and other common empirical theories. Irrespective of differences in other respects, the NS guiding principle has the same epistemic status as other guiding principles in other highly unified theories such as CM. We argue that only by pointing to the guiding principle-driven nature that it shares with CM and other highly unified theories, something no-one has done yet in this debate, one can definitively show that NS is not defective in F&PP’s sense: in the respects relevant to the debate, Natural Selection is as defective and as epistemically peculiar as Classical Mechanics and other never questioned theories. (shrink)

The aim of this paper is to revisit an ongoing controversy within the so called “Science Wars”; more specifically, I will address a particular topic within the “human nature” debate: the ontological and epistemological status of homosexuality. I claim that, in this particular chapter of the “Science Wars”, we are continually left in an explanatory impasse even when more data are collected, more rigorous experimental techniques are developed, more subtle arguments are offered and more pluralistic narratives are told. My diagnosis (...) of the source of this impasse leads me to the conclusion that here we are dealing with a structural problem that cannot be solved with an elaboration of new models and theories that maintain an on- tology and an epistemology that are no longer suited as an explanans of human nature in general, and homosexuality in particular. Nevertheless, my analysis of the structural features of the biological explanations and the constructivist counter-explanations also leads me to the belief that, although biologists do not fully understand the intricacies of subjects, neither constructivists understand the facticity of evolution and the challenge that it implies. If so, then the subject might be the right target of explanation. And, if so, constructivists might be right about the uniqueness of human homosexuality as a modern, western phenomenon explainable in terms of subjectivities and identities that mold and are molded by desires and institutions. But, if they are, evolution is not expendable because now we are facing a most intriguing question: How is that we humans became subjects? (shrink)

Framing systematics as a field consistent with scientific inquiry entails that inferences of phylogenetic hypotheses have the goal of producing accounts of past causal events that explain differentially shared characters among organisms. Linking observations of characters to inferences occurs by way of why-questions implied by data matrices. Because of their form, why-questions require the use of common-cause theories. Such theories in phylogenetic inferences include natural selection and genetic drift. Selection or drift can explain ‘morphological’ characters but selection cannot be causally (...) applied to sequences since fitness differences cannot be directly associated with individual nucleotides or amino acids. The relation of selection to sequence data is by way of downward or top-down causation from those phenotypes upon which selection occurs. The application of phylogenetic inference to explain sequence data is thus restricted to instances where drift is the relevant theory; those nucleotides or amino acids that can be explained via downward causation are precluded from inclusion in the data matrix. The restrictions on the inclusion of sequence data in phylogenetic inferences equally apply to species hypotheses, precluding the more restrictive approach known as DNA barcoding. Not being able to discern drift and selection as relevant causal mechanisms can severely constrain the inclusion and explanations of sequence data. Implications of such exclusion are discussed in relation to the requirement of total evidence. (shrink)

En este artículo defendemos la necesidad de reformular los conceptos de constreñimiento del desarrollo y variación considerando trabajos empíricos y teóricos recientes, principalmente sobre genes Hox, estado filotípico y morfogénesis. Argumentamos que la noción de variación isotrópica e ilimitada asociada con las teorías darwinianas y neodarwinianas deben ser reconsideradas a la luz de los aportes recientes de la biología del desarrollo. En esta visión, la variación estaría constreñida y sesgada. Esta reforma del concepto de variación coincide con la reformulación del (...) de constreñimiento, los cuales serían entendidos como un factor causal positivo en la evolución, en contraposición a como suelen ser entendidos en biología. (shrink)