Cooperation, altruism and naturalism - two lectures on evolutionary themes

Charles Darwin maintained that one of the biggest challenges to his theory was the question as to how genetically prescribed selfless behaviour could arise by natural selection, which is seemingly its antithesis. For the past half century biologists have focused on eusociality as the answer to that problem in which some individuals reduce their own lifetime reproductive potential to raise the offspring of others, illustrated most dramatically in the organization of social insects such as ants and honeybees in which sterile workers serve the reproductive needs of the Queen.

The key idea which has dominated research in this area is ‘inclusive fitness’, first stated by J.B.S.Haldane in 1955 and formalized by Bill Hamilton in 1964, stating that  cooperation is favoured by natural selection if  relatedness is greater than the cost to benefit ratio. In other words cooperation will tend to evolve if selfless behaviour favours close relatives since this will ensure a greater representation of the selfless individual’s genes in subsequent generations, hence ‘inclusive fitness’. The idea led to a fruitful research programme, particularly in the 1970s and 1980s, which gathered a considerable body of data consistent with such kin selection theory.

Martin Nowak, however, Professor of Biology and of Mathematics at Harvard University and Director of Harvard’s Program for Evolutionary Dynamics, wishes to change the goal-posts in this discussion and create a new paradigm. Just how far that paradigm will stretch should become clearer at his lecture entitled  ‘The Evolution of Cooperation’ to take place on Monday, May 28^th at 5.30 p.m. in Buckingham House Lecture Theatre, Murray Edwards College, sponsored by the Faculty of Divinity in collaboration with The Faraday Institute for Science and Religion based at St. Edmund’s College.

Prof. Nowak’s ideas have been disseminated recently in a series of high profile reviews, notably in a Nature review co-authored with the mathematician Corina Tarnita and the well-known entomologist Edward Wilson entitled ‘The evolution of eusociality’ [Nature 466: 1057-1062, 2010] in which the authors point out the limitations of kin selection theory and argue instead that standard natural selection theory does a better job at explaining the evolution of cooperation. Elsewhere Nowak has likened inclusive fitness to a redundant Ptolemaic epicycle, remarking that "Somehow you have the impression that there is some reality attached to it, but the actual mathematical description of any evolutionary process shows that evolutionary fitness is an unnecessary concept."

More recently Nowak has suggested in his book SuperCooperators, co-authored with Roger Highfield, that cooperation is an essential third pillar in the evolutionary process along with genetic variation and natural selection. Two key strategies for cooperation are ‘direct reciprocity’ – I treat you according to how you have treated me’ – and ‘indirect reciprocity’ – I treat you according to your reputation. Nowak likes to quote his Harvard colleague David Haig on this point: “For direct reciprocity you need a face; for indirect reciprocity you need a name”. It was the evolution of language, suggests Nowak, that allowed humanity to become ‘supercooperators’ by facilitating indirect reciprocity.

Why should a lecture on the finer points of the evolution of cooperation be sponsored by the Faculty of Divinity and an Institute of science and religion? The answer is not hard to see. Although more recent workers in the research field have tended to use the word ‘cooperation’, traditionally ‘evolution of altruism’ is the more common terminology. Altruism is clearly a word loaded with theological significance, but also a slippery word, carrying several distinct meanings. In Christian theology altruism is associated with agape, God’s self-giving love in Christ which seeks no reward, the kind of love that followers of Christ are expected to practice.  The technical biological definition of altruism – ‘favoured by natural selection if relatedness is greater than the cost to benefit ratio’ – entails that whatever it is, it cannot be agape, because in this case there is a clear reward: the investment of one’s own genes in the inheritance of another.

Maintaining the distinctive language of biological and theological narratives is an important aspect of the science-religion dialogue. This will be the theme of a second high-profile lecturer in Cambridge this week, Elliott Sober, Professor of Philosophy at the University of Wisconsin-Madison, who on Thursday May 24^th at 5.30 p.m. in the same venue at Murray-Edwards College, will be giving this term’s Faraday Lecture on ‘Naturalism and Evolutionary Theory’. Do Darwinian narratives render other forms of narrative, such as religious accounts, redundant? More broadly, can conclusions about God – for example, that he does not exist, or that he lacks this or that property if he does exist - be deduced from well-established scientific theories?

Coming so close together, these two lectures will themselves act as fascinating narratives on two aspects of the evolutionary story that are far more intertwined than might at first glance be apparent.

Denis Alexander is the Director of The Faraday Institute for Science and Religion [www.faraday-institute.org] at St. Edmund’s College, where he is a fellow.