International Society for History, Philosophy, and Social Studies of Biology

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THURSDAY, JULY 9  /  09:00 - 10:30  /  DS-R520
Individual papers
Modeling Emergence in Systems Biology

Mechanistic explanation in systems biology: Cellular networks

Dana Matthiessen (Georgetown University, United States)

Mechanistic philosophy draws heavily from examples in the fields of molecular biology, neuroscience, and basic cell biology. While authors acknowledge its adequacy for such fields, it is frequently contended that, as biological systems approach higher levels of behavioral and compositional complexity, the explanatory purchase of standard mechanistic concepts and strategies begins to falter. In particular, the sufficiency of mechanistic philosophy is currently being disputed for research that falls under the banner of 'systems biology'. While some hold that systems biology is mechanistic, others argue that it involves a distinct, non-mechanistic form of explanation. I will evaluate these latter claims with respect to a representative program in systems biological research: the study of regulatory networks within single-celled organisms. I argue that these networks are amenable to mechanistic philosophy without need to appeal to some alternate form of explanation. My aim is not to simply redefine or expand the concept of mechanism in a way that conveniently subsumes the objects of systems biology. Rather, I intend to show how commonly accepted postulates and procedures of mechanistic philosophy apply to and are referenced within the study of cellular networks. In addressing the critics, I aim to advance a picture of mechanistic science that is in accord with the methodology of those studying cellular networks. For this I will draw on a depiction of the explanatory strategies of mechanistic science, which I owe to Craver and Darden (2013) and who cover it in greater detail. After arguing for the compatibility of systems biology with these strategies, I will consider and reject an alternative view of systems biology, which I associate with the notion of design explanation.

Canalization and developmental processes: Beyond a neopreformationist interpretation of the cryptic genetic variability

Flavia Fabris (Sapienza – Università di Roma, Italy)

The concept of canalization, coined by Waddington to illustrate the complex functioning of all developmental processes, has been recently subjected to some neopreformationist interpretations centered on the role of the notion of cryptic genetic variability. Waddington attributed the evidence of the genetic assimilation of acquired characters to this concept, claiming that all organisms are complex homeorhetic systems with specific abilities to influence the evolutionary pathways through the regulation of buffering mechanisms of genetic variability. I will suggest that contemporary biotechnological approaches have misrepresented the original content of the concept of cryptic genetic variability, transforming it into a mere genetic informationism. I will argue that the heuristic value of the concept of canalization has been reduced to a static representation of an “a-contextual developmental system”, closed with respect to its environment. The idea will be evaluated analyzing the contemporary assumptions of canalization in molecular biology research with the aim to recover the original meaning of the concept as an open interaction process between the organism and its environment.

Multicellularity and the type of functional integration for organismal interaction

Argyris Arnellos (Konrad Lorenz Institute for Evolution and Cognition Research, Austria)

Multicellularity raises conceptual challenges for understanding organismal interaction. Although multicellularity comes in different characters and in various types and forms, almost all multicellular (MC) systems (from biofilms and colonies to modular and full-fledged MC systems) exhibit some kind of functional integration that in turn allows them to deploy collectively coordinated interactions with their environments. Through such interactions MC systems are able to maintain their organization, to explore niches, and to increase the possibility of survival of their constituting units and of the systems themselves, as a whole. Notwithstanding the resulting adaptation at the global level, I argue (contrary to neo-Darwinian and adaptationist approaches) that not all MC interactions can be considered organismal. Adopting an organizational perspective, I distinguish between a constitutive level (CL - developmental and metabolic processes) and an interactive level (IL - the functional interactions that the system exerts in the environment) of a MC organization. I discuss three types of coordination of MC interaction (representing almost all cases), and I explain that their realization requires different organizational relations between the two levels. I suggest that organismal interaction requires a specialized regulatory subsystem (produced and maintained by the CL) able to modulate both the coordination of the set of structures responsible for the execution of the interactions with the environment (IL) as well as the metabolic processes that constitute and support these interactions (CL). I argue that the endogenous production and operation of such a regulatory subsystem entails a certain form of global functional integration, which in a complete contrast to the other two cases renders the related interactions genuinely attributable to the whole MC system. I discuss in detail the consequences of such type of functional integration regarding the interdependence between IL and CL, and I conclude with implications for the organismal status of several MC systems.