Celso Neto

According to the species-as-individuals thesis(hereafter S-A-I), species are cohesive entities. Barker and Wilson recently pointed out that the type of cohesion exhibited by species is fundamentally different from that of organisms (paradigmatic individuals), suggesting that species are homeostatic property cluster kinds. In this article, I propose a shift in how to approach cohesion in the context of S-A-I: instead of analyzing the different types of cohesion and questioning whether species have them, I focus on the role played by cohesion in the identity of individuals. This shift allows us to recognize why cohesion matters to S-A-I, as well as to reconceive the analogy between species and organisms (paradigmatic individuals), and also allows us to highlight the context sensitivity of both ‘‘cohesion’’ and ‘‘individuals.’’ From this perspective, I identify two problems in Barker and Wilson’s argumentation. Firstly, the authors fail to recognize that species are individuals even if they do not have the same type of cohesion that organisms have. Secondly, their argument relies on a misinterpretation of S-A-I. I conclude that species cohesion is still best framed as a feature of species individuality rather than a feature of species as homeostatic property cluster kinds. The arguments presented here contribute to the re-articulation and reevaluation of S-A-I in the face of contemporary discussions.

Contrary to the common-sense view and positivist aspirations, scientific concepts are often imprecise. Many of these concepts are ambiguous, vague, or have an under-specified meaning. In this paper, I discuss how imprecise concepts promote integration in biology and thus benefit science. Previous discussions of this issue focus on the concepts of molecular gene and evolutionary novelty. The concept of molecular gene helps biologists integrate explanatory practices, while the notion of evolutionary novelty helps them integrate research questions into an interdisciplinary problem New directions in the philosophy of science, Springer, Dordrecht, 2014). In what follows, I compare molecular gene and evolutionary novelty to another imprecise concept, namely biological lineage. This concept promotes two other types of scientific integration: it helps biologists integrate theoretical principles and methodologies into different areas of biology. The concept of biological lineage facilitates these types of integration because it is broad and under-specified in ways that the concepts of molecular gene and evolutionary novelty are not. Hence, I use the concept of biological lineage as a case study to reveal types of integration that have been overlooked by philosophers. This case study also shows that even very imprecise concepts can be beneficial to scientific practice.

Many contemporary biologists and philosophers of biology admit that selection occurs at any level of the biological hierarchy at which entities showing heritable variation in fitness are found, while insisting that fitness at any level entails differential reproduction, not differential persistence. Those who allow that persistence can be selected doubt that selection on nonreproducing entities can be reiterated, to produce “complex adaptations.” We present here a verbal model of subclones evolving in a simple idealized chemostat that calls into question these suppositions and is usefully explanatory when taken as an analogy to selection for persistence of clades.

In this paper, I show how idealizations contribute to social activities in science, such as the recruitment of experts to a research project. These contributions have not been explicitly discussed by recent philosophical accounts of scientific idealization. These accounts have focused on how idealizations influence activities like scientific theorization, explanation, and modeling. Other accounts focus on how idealizations influence policy-making and science communication. I expand these accounts by exploring the uses of idealized phylogenetic trees in science. Trees are not only useful for improving our understanding and public communication of evolutionary history, but they also help with the organization of laboratories and collaboration among scientists. Attending to the relation between idealizations and these social practices in science matters. It can help us understand why idealized models become entrenched and why certain social practices change over time.

This article defends lineage pluralism; the view that biological lineages are not a single, unified type of entity. I analyze aspects of evolutionary theory, phylogenetics, and developmental biology to show that these areas appeal to distinct notions of lineage. I formulate three arguments for lineage pluralism. These arguments undercut the main motivations for lineage monism; the view that biological lineages are a single, unified type of entity. Although this view is rarely made explicit, it is often assumed in philosophy and biology. Hence, this article sheds light on this monistic assumption and shows why lineage pluralism should be adopted instead.