Birch, Jonathan (2014) Gene mobility and the concept of relatedness. [Preprint]

Preview

PDF Gene_mobility_(2014).pdf Download (1MB)

Abstract

Cooperation is rife in the microbial world, yet our best current theories of the evolution of cooperation were developed with multicellular animals in mind. Hamilton’s theory of inclusive fitness is an important case in point: applying the theory in a microbial setting is far from straightforward, as social evolution in microbes has a number of distinctive features that the theory was never intended to capture. In this article, I focus on the conceptual challenges posed by the project of extending Hamilton's theory to accommodate the effects of gene mobility. I begin by outlining the basics of the theory of inclusive fitness, emphasizing the role that the concept of relatedness is intended to play. I then provide a brief history of this concept, showing how, over the past fifty years, it has departed from the intuitive notion of genealogical kinship to encompass a range of generalized measures of genetic similarity. I proceed to argue that gene mobility forces a further revision of the concept. The reason in short is that, when the genes implicated in producing social behaviour are mobile, we cannot talk of an organism’s genotype simpliciter; we can talk only of an organism's genotype at a particular stage in its life cycle. We must therefore ask: with respect to which stage(s) in the life cycle should relatedness be evaluated? For instance: is it genetic similarity at the time of social interaction that matters to the evolution of social behaviour, or is it genetic similarity at the time of reproduction? I argue that, strictly speaking, it is neither of these: what really matters to the evolution of social behaviour is diachronic genetic similarity between the producers of fitness benefits at the time they produce them and the recipients of those benefits at the end of their life-cycle. I close by discussing the implications of this result. The main payoff is that it makes room for a possible new mechanism for the evolution of altruism in microbes that does not require correlated interaction among bearers of the genes for altruism. The importance of this mechanism in nature remains an open empirical question.

---

Export/Citation:

EndNote | BibTeX | Dublin Core | ASCII/Text Citation (Chicago) | HTML Citation | OpenURL

Social Networking:

Share |

---

Item Type:	Preprint
Creators:	Creators Email ORCID Birch, Jonathan jgb37@cam.ac.uk
Keywords:	gene mobility; kin selection; inclusive fitness; microbiology; relatedness; social evolution
Subjects:	Specific Sciences > Biology Specific Sciences > Biology > Evolutionary Theory Specific Sciences > Biology > Molecular Biology/Genetics
Depositing User:	Dr Jonathan Birch
Date Deposited:	03 Apr 2014 19:44
Last Modified:	03 Apr 2014 19:44
Item ID:	10593
DOI or Unique Handle:	10.1007/s10539-014-9445-z
Subjects:	Specific Sciences > Biology Specific Sciences > Biology > Evolutionary Theory Specific Sciences > Biology > Molecular Biology/Genetics
Date:	3 April 2014
URI:	https://philsci-archive.pitt.edu/id/eprint/10593

Monthly Views for the past 3 years

Monthly Downloads for the past 3 years

Plum Analytics

Altmetric.com

Actions (login required)

View Item