For Martin Nowak cooperation is the master architect of evolution. This man is obsessed with the idea that cooperation is an indispensable driving force of evolution at any level - mutation, selection and cooperation. Without cooperation among RNAs in the primordial soup, you and me would be still one of them. Is he crazy? Nowak has been Professor of Mathematical Biology at Oxford, the first head of the Program in Theoretical Biology at the Princeton Institute for Advanced Study, and now he is full professor of Biology and Mathematics at Harvard University in his own institute called "Nowakia". Of his numerous papers more than 50 were published in Nature or Science. Nowak is a leading evolutionary theorist of our time. Why is he crazy for cooperation?
Cooperation has always been Nowak's main subject that he studies mostly with only one technique: mathematics. "We can capture the way it (evolution) works with mathematics, distilling its essence into the form of equations." "SuperCooperators" is the grand review of his oeuvre on cooperation, a kind of textbook that reads like a bestselling novel with a wonderfully lucid and enthusiastic style, thanks to Nowak's ghost-writer and kind of co-author ("with" instead of "and") Roger Highfield, an ingenious science writer and the editor of the New Scientist magazine. A layperson could enjoy just reading this book and finally has happened to learn most about a fascinating part of biology. Imagine all textbooks were written this way! Try this appetizer from the chapter on the evolution of language: "Gossip. Banter. Chat. Let's talk. Let's organize a colloquium. Even better, let's have a party! Language allows people to work together, to exchange their ideas, their thoughts, and their dreams. In this way language is intimately linked with cooperation. For the mechanism of indirect reciprocity it needs gossip, from names to deeds and times and places, too. Indirect reciprocity is the midwife of language and of our big, powerful brain."
We learn about five ways to achieve cooperation: (1) Direct reciprocity - Tit for Tat that becomes generous but has to give way to the new champion for playing the Prisoner's Dilemma, "win stay, lose shift"; (2) Indirect reciprocity - Power of reputation. This seems to be the most important mechanism driving our sociality, language and brains; (3) Spatial games - Chessboard of life. Cooperators can prevail by forming networks and clusters; (4) Group selection - tribal wars; multilevel (group) selection works if there are many small, isolated groups; migration - egoists infecting pure altruist groups - undermines cooperation; however, "at the cellular level, there's plenty of evidence of group selection"; (5) Kin selection - Nepotism. Cooperate with close kin and defect with strangers according to Hamilton's rule. Nowak is reluctant to list kin selection as a mechanism for cooperation: "I still believe that kin selection is a valid mechanism if properly formulated."
Kin selection and inclusive fitness theory has been one of the corner stones of our understanding of the evolution of social behaviour. Hamilton's rule, b/c>1/r, was the e=mc2 of sociobiology until very recently when Nowak, Tarnita and Wilson in an Analysis article in Nature claimed that it's theoretical basis is mistaken, Hamilton's rule almost never holds and decisive empirical tests of inclusive fitness theory have never been performed. This article induced a strong reaction in the huge community of well-established researchers that made their career with studying kin selection. In SuperCooperators Nowak explains his criticism. In "The math of kin selection" he reviews the history of the concept, from Haldane's answer to whether he would risk his life to save a drowning man: "No, but I would do it for two brothers or eight cousins", to Hamilton, Price and Maynard Smith's final version. Around explaining the Price equation, the basis of current inclusive fitness theory, we learn about the biography of Bill Hamilton and George Price, and why Price's equation is the mathematical equivalent of a tautology.
In the chapter "The decline of inclusive fitness" Nowak writes: "Equations seemed to arise out of nowhere in kin selection. There were many attempts at calculations that had no precise formulation of the underlying mathematical model ... This is a recipe for disaster", and "We found that in this special world (`inclusive fitness land') where inclusive fitness theory works, the calculations yield up exactly the same prediction as standard natural selection theory. Hence inclusive fitness theory comes up with no novel predictions or insights." Nowak offers a new model for the evolution of eusociality where relatedness is a consequence rather than the cause of social behaviour: A mutant determines that daughters just stay with the nest and thus happen to stay with their mother to help raising further offspring. However, what if they happen to stay with someone unrelated? Why do parents insist on caring for their own offspring? - because they happened to be close at birth and not because they are related? As an empiricist I see many empirical results supporting the relatedness cause: e.g., the sex ratio in singly mated ants is closer to the workers' benefit than to the queen's, it's the contrary in slave maker ants where workers are in an evolutionary dead end. I expect a new "properly formulated" theory of social evolution based on relatedness will be compatible with existing evidence and include Hamilton's rule "of thumb". It will offer a plethora of new predictions enthusiastically tested by next generation students of sociality.
Nowak strongly objects also to punishment being an effective method for promoting cooperation. "But this view is mistaken in my opinion" and he dissects Fehr and Gächter's classic paper to depict any shortcomings. On this topic the winning team "Nowak & Sigmund" seem to be split: Sigmund: "Punish or Perrish", Nowak: "Punish and Perrish". Nowak, the theorist, even performed experiments to show that "Winners don't punish." Indeed, we do not know yet, how punishing ultimately pays off for the punisher. In another experiment Nowak tried to prove that positive (reward) rather than negative interactions (punishment) promote public cooperation, which turned out to be only wishful thinking. As with his attack on the basis of kin selection theory, Nowak challenges the established view on the evolution of punishment, potentially stirring up novel yet un-thought ideas.
SuperCooperators is also Nowak's autobiography. He reveals his private life - how he coming from an all-boys school met his wife - and his way of interacting with his supporters: mountain climbing with Peter Schuster, walking through Rauriser Urwald with Karl Sigmund, playing soccer with Bob May, or dining with Jeffrey Epstein, the Wall Street tycoon, who built an institute for him, at the beach of Epstein's Carebian island of paradise. Nowak has also some personal sentences about each of his successful collaborators and some pages on how "the eternal symphony" (Mahler's Song of the Earth) carried a deep resonance for him and his work.
Finally, Nowak describes the game that all people on Earth are playing - the climate game: "unless people fully realize the extent to which the planet is in peril, people will fail to do enough to save it .... I believe that climate change will force us to enter a new chapter of cooperation." In search of a deeper concept that underpins all apparently different approaches to cooperation he presents the solution: "Corina's theorem will hold for any evolutionary process on Earth, in this galaxy, as well as all the others, from those nearby to agglomerations of ancient stars that lurk in the faintest, farthest reaches. It applies to any and every game in the cosmos....."
