IAS-Research Talk by Javier Suárez: “Stability of Traits as the Kind of Stability That Matters in a Holobiont”

Date and time: November 7, Tuesday, 12:15 a.m.

Location: Carlos Santamaría Building, Room B14.

Speaker: Javier Suárez (http://www.ub.edu/grc_logos/javier-suarez1) is PhD student in philosophy at the University of Barcelona and the University of Exeter.

Abstract: Holobionts are biological entities that consist of a multicellular eukaryotic host plus its symbiotic microbiota. Holobionts are supposed to be pervasive and they are supposed to bear emergent traits, resulting from the dynamic interactions between the host and its symbionts. Defenders of the holobiont have recently developed the “hologenome concept of evolution”, according to which holobionts are units of selection in evolution. This claim has been recently contested by many, who claim that holobionts cannot be units of selection because the entities that compose a holobiont are not faithfully transmitted intergenerationally and therefore their influence in the holobiont is not evolutionarily constant. In this paper, I contend their argument by distinguishing between the notions of stability of lineages and stability of traits. Stability of lineages requires the different species that integrate a holobiont to be transmitted every generation in order to have a unit of selection. Stability of traits, however, requires that the traits that are identified in every new generation of holobionts are the same, in order to have a unit of selection. I defend that the arguments that have been offered against the role of holobionts as units of selection assume the idea of stability of lineages and argue that the idea of stability of traits is more suitable for capturing the role of holobionts as units of selection.