I investigate the intrinsic/extrinsic nature of stemness in muscle stem cells (MSC) by relying on recent research on quiescence, with the aim of shedding light on the nature of dispositions and deriving some consequences about stem cells. First, I argue why the study of quiescence is the best available way to establish any claim about the intrinsicness/extrinsicness of stemness at least is some stem cells. Drawing on that, I argue that MSC’s stem capacities result from the combination of intrinsic cues (...) plus extrinsic factors from the stem cell niche, making stemness an extrinsic disposition in MSC. Importantly, it is shown that the niche allows the instantiation of stemness in MSC by acting as a masker of its manifestation. This shows that stemness is, at least in MSC, what I call an extrinsically structurally masked disposition (SMD); that is, a disposition whose instantiation requires, as a condition of possibility, the interaction between the bearer and a masker. Finally, I conclude by suggesting some potential consequences of this observation for the philosophical study of dispositions and for stem cell research. (shrink)

An understanding of the factors behind the evolution of multicellularity is one of today’s frontiers in evolutionary biology. This is because multicellular organisms are made of one subset of cells with the capacity to transmit genes to the next generation and another subset responsible for maintaining the functionality of the organism, but incapable of transmitting genes to the next generation. The question arises: why do somatic cells sacrifice their lives for the sake of germline cells? How is germ/soma separation maintained? (...) One conventional answer refers to inclusive fitness theory, according to which somatic cells sacrifice themselves altruistically, because in so doing they enhance the transmission of their genes by virtue of their genetic relatedness to germline cells. In the present article we will argue that this explanation ignores the key role of policing mechanisms in maintaining the germ/soma divide. Based on the pervasiveness of the latter, we argue that the role of altruistic mechanisms in the evolution of multicellularity is limited and that our understanding of this evolution must be enriched through the consideration of coercion mechanisms. (shrink)

Both concepts of the holobiont and the immune system are at the heart of an ongoing scientific and philosophical examination concerning questions of the organism’s individuality and identity as well as the relations between organisms and their environment. Examining the holobiont, the question of boundaries and individuality is challenging because it is both an assemblage of organisms with physiological cohesive aspects. I discuss the concept of immunity and the immune system function from the holobiont perspective. Because of the host-microbial close (...) relations of codependence and interdependence, the holobiont is more often than not confused with the host, as the host is the domain in which this entity exists. I discuss the holobiont unique ecological characteristics of microbial assemblages connected to a host in a network of interactions in which the host is one of the organisms in the community but also its landscape. Therefore, I suggest viewing the holobiont as a host-ecosystem and discuss the implication of such a view on the concept of immunity and the meaning of protection. Furthermore, I show that viewing the holobiont as a host ecosystem opens the possibility of using the same ecological definition of boundaries and immunity dealing with an ecological system. Thus, the holobiont’s boundaries and immunity are defined by the persistence of its complex system of interactions integrating existing and new interactions. This way of thinking presents a notion of immunity that materializes as the result of the complex interdependence relations between the different organisms composing the holobiont similar to that of an ecosystem. Taking this view further, I discuss the notion of immunogenicity that is ontologically heterogeneous with various causal explanations of the processes of tolerance and targeted immune response. Finally, I discuss the possible conceptualization of already existing and new biomedical practices. (shrink)

One Health medicine aims to improve health by focusing on the relations between the health of humans, animals, and the environment. However, One Health does not provide a clear idea of these relations, which are still represented as conceptually separated and not as one health, as the name implies. Inspired by holobiont research, I suggest a new model and conceptual framework for One Health that expands the notion of the biological patient by providing a gradational and dynamic understanding of environments, (...) patients, and their relations. This new model conceptualizes humans and non-humans, individual organisms, and collectives, as belonging to one system that allows for more or less inclusive understandings of patients. As such, it resolves the conceptual tensions of different One Health approaches and supports the implementation of One Health as an interdisciplinary research field. (shrink)

One of the central questions in the metaphysics of pregnancy is this: Is the foetus a part of the mother? In this paper I aim not to answer this question, but rather to raise methodological concerns regarding how to approach answering it. I will outline how various areas attempt to answer whether the foetus is a part of the mother so as to demonstrate the methodological problems that each faces. My positive suggestion will be to adopt a method of reflective (...) equilibrium. The aim of this is to ensure that pregnancy be included in the tribunal of experience that our theories are held up against such that our theories can accommodate what we say about pregnancy, whilst also ensuring that what we say about pregnancy be theoretically informed. That way, we rethink pregnancy in light of our theories as well as rethinking our theories in light of pregnancy. (shrink)