Gene Mobility and the Concept of Relatedness

Biology and Philosophy 29 (4):445-476 (2014)
  Copy   BIBTEX

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

Similar books and articles

The Hamiltonian view of social evolution.J. Arvid Ågren - 2018 - Studies in History and Philosophy of Science Part C: Studies in History and Philosophy of Biological and Biomedical Sciences 68:88-93.
Kin Selection: A Philosophical Analysis.Jonathan Birch - 2013 - Dissertation, University of Cambridge
The Philosophy of Social Evolution.Jonathan Birch - 2017 - Oxford: Oxford University Press.
Hamilton’s Two Conceptions of Social Fitness.Jonathan Birch - 2016 - Philosophy of Science 83 (5):848-860.
Inclusive Fitness as a Criterion for Improvement.Jonathan Birch - 2019 - Studies in History and Philosophy of Science Part C: Studies in History and Philosophy of Biological and Biomedical Sciences 76:101186.

Analytics

Added to PP
2014-04-04

Downloads
557 (#35,614)

6 months
110 (#49,362)

Historical graph of downloads
How can I increase my downloads?

Author's Profile

Jonathan Birch
London School of Economics

Citations of this work

Kin Selection, Group Selection, and the Varieties of Population Structure.Jonathan Birch - 2020 - British Journal for the Philosophy of Science 71 (1):259-286.
The Inclusive Fitness Controversy: Finding a Way Forward.Jonathan Birch - 2017 - Royal Society Open Science 4 (170335):170335.
Unexplained cooperation.Eva Jaffro & Cédric Paternotte - 2021 - European Journal for Philosophy of Science 11 (3):1-21.
Starting small: Using little microbes to tackle big philosophical problems.Makmiller Pedroso - 2015 - Studies in History and Philosophy of Science Part C: Studies in History and Philosophy of Biological and Biomedical Sciences 53:126-128.

View all 6 citations / Add more citations

References found in this work

How to define theoretical terms.David Lewis - 1970 - Journal of Philosophy 67 (13):427-446.
How to Define Theoretical Terms.David Lewis - 1970 - Journal of Symbolic Logic 36 (2):321-321.
Processes of Life: Essays in the Philosophy of Biology.John Dupré - 2011 - Oxford, GB: Oxford University Press.
Processes of Life: Essays in the Philosophy of Biology.John Dupré - 2011 - New York: Oxford University Press UK.
Hamilton’s rule and its discontents.Jonathan Birch - 2014 - British Journal for the Philosophy of Science 65 (2):381-411.

View all 10 references / Add more references