Abstract: Cell-matrix adhesion complexes (CMACs) are regions responsible for cellular attachment to the extracellular matrix (ECM), they are mainly composed by integrins, α/β heterodimers that bind selectively different ECM components through their extracellular domains acting as receptors for this class of molecules. Upon ECM binding the cytoplasmic tails of integrins will interact with a wide range of recruited factors that regulate integrin clustering in the cell membrane; and also activate signaling pathways that will provide a physical linkage between activated integrins and the microfilament system to be remodeled during cell migration. Ultimately CMACs work as functional protein networks that dynamically connect the ECM to filamentous Actin, controlling cell migration precisely through the continual rearrangement of both ECM adhesion, and Actin polymerization. In the present work we shall examine some attempts to conceptualize “cell migration” as an emergent process developed in the recent specialized literature; they introduce the notions of hierarchic organization into levels i.e. molecular, sub-cellular and cellular and describe an informational flow of increasing complexity versus decreasing number of entities, between these levels. We shall discuss few examples of CMACs remodeling in particular physiological and pathological conditions to argue that cell migration is a process that is also organized into semiotic dimensions. Our approach will not come as an alternative to the systems biology conceptualization initially presented but as a complementary view. Beyond the syntactic level – here illustrated as specific recognition of discrete ECM protein sequences by distinct integrin heterodimers – we shall reach the semantic and pragmatic levels by bringing into light the dynamics of some “word games”, i.e. Lewis Carroll’s doublets; and magic squares. In such poetic games the synthetic transformations subjected by the words have to deal with semantic rules, but are ultimately dictated by meaning, as concrete pragmatic constrains. We will emphasize the integration of synthetics, semantics and pragmatics also for the CMACs continuous remodeling through cell migration.

Abstract: A cladogram is usually considered as resolved when all its branching points are bifurcations. The question I ask is: Why? Why all phylogenetic methods search dichotomous trees? Is evolution, or speciation, dichotomous? I suggest that Hennig’s principle of dichotomy is theoretically grounded. Cladograms—taxa and their relationships—are the result of a Cartesian analysis, which consists of the decomposition of taxa into homologies, i.e. hypotheses of degree of identity. Now, degree of identity is best represented by a ternary relationship, where two features are more identical to each other than any is to a third one. The foundation of taxa and their relationships upon homologies thus results in an intrinsically dichotomous pattern.

I speculate that the theoretical principle of dichotomy was present in Hennig’s theory. However, somehow, Hennig “forgot” his own arguments and the justification for this part of his theory.

Finally, I draw consequences of the theoretical foundation of dichotomy: if the evolutionary process needs not to be dichotomous, in which way are phylogenetic trees phylogenetic?

Abstract: While the topic of natural kinds has long been a focus of work in the philosophy of science, as well as in other areas of philosophy, a generally accepted account of natural kinds is still lacking. Moreover, there even is no general agreement about the kind of account that is being searched for, or about the criteria that a good account of natural kinds should meet. In response to these problems, in the philosophy of science (though not in other areas) there is a trend to move away from the metaphysics of kinds and classification and to turn to epistemological issues and questions regarding the use of kinds and classifications in various contexts. This trend fits well with the renewed interest in doing naturalistic philosophy of science and the increasing calls for bringing philosophy of science closer to scientific practice.

However, abandoning the search for a metaphysics of kinds and classifications is too quick. A metaphysical account of kinds is a crucial element of the explanation why some kinds and classifications are used in the sciences with more success than others, and some ways of grouping things turn out not to be useful at all. After all, barring cases of epistemic luck the reason for the epistemic and practical success of kinds and classifications must be that they adequately represent some aspect of the world or other. But problem for naturalistic philosophers wanting to elucidate the metaphysics of scientific kinds and classifications is whether naturalistic and practice-oriented philosophy of science can at all come up with an account of the metaphysics of kinds and classifications, rather than staying with epistemological and practical issues. Metaphysics cannot be read off from either epistemology or practice: simply examining scientific kinds and classifications and the ways in which investigators in the various areas of science employ them will not reveal their underpinnings. Thus, some a priori considerations need to enter into the picture – but a priori metaphysics is suspect from a naturalistic viewpoint.

The challenge for a naturalistic and practice-oriented metaphysics of kinds and classification, then, is to bring a priori considerations into play without rendering the account insufficiently naturalistic. In this talk I addresses this challenge and explore what a thoroughly naturalistic metaphysics of kinds and classifications should look like. I will do this by examining two core notions in the debate on kinds and classification, namely the notions of naturalness and, in particular, normativity.