Why, of all the species that have ever existed, have only us humans reached this unparalleled level of intelligence and social organisation? When a senior scientist such as Edward O. Wilson trains his mind on such a question, you hope to be in for a treat.
Wilson is considered the father of sociobiology and specialises in the biology of ants and social insects more generally. Now rapidly approaching 90 years of age, he has in recent years written more widely outside of his field of biological expertise, pondering human evolution in books such as The Social Conquest of Earth, The Origins of Creativity, and The Meaning of Human Existence. In Genesis, he forges a bridge between that work and his original love, the social insect.
The major transitions in evolution as outlined by John Maynard Smith and Eörs Szathmáry in their eponymous book serve as the starting point for Wilson’s argument. Briefly, these were: life’s origin; complex, eukaryotic cells; sexual reproduction; multicellularity; animal societies; and language (see The Major Transitions in Evolution and The Major Transitions in Evolution Revisited). He then quickly focuses on eusociality: the ability to cooperate and divide labour, i.e. behave in an altruistic manner. As he points out, each of these transitions depends on altruism of a sort, as it requires parts to cooperate to come together into larger wholes.
It is the fifth step, animal societies, that is truly an evolutionary challenge, writes Wilson. According to this book, amongst all the insects and vertebrates, there are at least 17 species known to have reached this stage. That is not many at all. Wilson here really drew me in with a clever building of tension and asking of questions. He spends several chapters on social insects, his area of expertise. Termites (see my review of Underbug: An Obsessive Tale of Termites and Technology) and ants were some of the first. But they were also some of the few. Despite insects being a fascinating group showing so many gradations of social complexity, only very few have evolved what Wilson calls true eusociality, with a specialized reproductive caste and a non-reproductive worker caste that labours in the colony. Wilson walks the reader through some of these gradations, along the way making the interesting observation that close kinship is not a cause but a consequence of eusociality.
“[…] the fifth [great transition in evolution], animal societies, is truly an evolutionary challenge”
A key precondition, says Wilson, is the raising of young in a protected setting such as a nest. But this is common, so why do we not see more eusociality? Wilson’s answer is intriguing for sure: mutations in one or more genes can make a eusocial colony, but the remainder of the original genome is, at this point, still adapted for a solitary life. And that is the barrier to eusociality. To overcome it requires group selection: the selection of genes that prescribe social traits. He quotes David Sloan Wilson – who argued that selfish individuals will beat altruistic ones, but groups of altruistic individuals will beat groups of selfish ones – and proceeds to give some examples from the social insect world.
This is where I felt the book was starting to falter a bit. The problem is that group selection is not a widely accepted idea amongst evolutionary biologists, who instead favour kin selection and inclusive fitness theory. A 2010 Nature publication on which Wilson was one of three authors resulted in a rebuttal authored by no fewer than 137 contributors (see also Evolutionary Restraints: The Contentious History of Group Selection). Wilson here continues his criticism of this rival idea, but remains silent on group selection’s contested status. As a consequence, I also feel he does not explain it as thoroughly as I would have liked so as to fully understand it.
At this point, Wilson is six chapters into a seven-chapter book. So, what about humans and human societies then? He basically retreads Wrangham’s thesis outlined in Catching Fire: How Cooking Made Us Human. Fire gave rise to cooking and with it shared meals and thus a powerful opportunity for social bonding. And here language would have been favoured too.
“[…] David Sloan Wilson argued that selfish individuals will beat altruistic ones, but groups of altruistic individuals will beat groups of selfish ones”
Wilson ends his argumentation very abruptly, in his last paragraph still explaining the minutiae of a study before in one sentence wrapping it up. I hate to say this, but it feels rushed, almost as if someone took the manuscript from his hands as he was writing it (“Sorry, Professor Wilson, but your time for this assignment is up, could you please write your last sentence and then put your pen down?”). There is very little in the way of an overview of the thinking on language evolution (see e.g. How Language Began: The Story of Humanity’s Greatest Invention, The Evolution of Language, or Why We Talk: The Evolutionary Origins of Language), its cognitive and neurobiological underpinnings (see e.g. Language in Our Brain: The Origins of a Uniquely Human Capacity or The Social Origins of Language), its roots in more primitive forms of communication (see e.g. The Truth about Language: What It Is and Where It Came from or How Language Began: Gesture and Speech in Human Evolution), the study of extant languages (see e.g. Language in Prehistory), or why it only evolved in humans (see e.g. Why Only Us: Language and Evolution or my review of Why Chimpanzees Can’t Learn Language and Only Humans Can). From the hands of Wilson, you would expect a very capable and readable overview, so this feels like a missed opportunity.
Genesis is certainly an intriguing read that it is well presented: each chapter features a nice illustration, a stand-out full-page summary or comment mid-way, and nice chapter headings. At 125 pages, this novella-length book is a quick read, and I have to say that Wilson writes beautifully – I will certainly seek out his other books. True to its subtitle, it discusses the (very) deep origins of societies by focusing on social insects and his ideas on group selection, but the human evolution story seems an afterthought. With the book ending so abruptly, it is hard not to come away feeling that Genesis could have been more fully developed.
Disclosure: The publisher provided a review copy of this book. The opinion expressed here is my own, however.
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