Darwin's Unfinished Symphony

This is a very impressive interdisciplinary work about cultural evolution that draws on the author's research over a 30-year period about the ways in which culture drives the development of the human mind, addressing the fundamental question about how evolutionary processes have resulted in our unique human heritage. It covers social learning across many species in terms of imitation and copying, showing how 'the learned and transmitted activities of our ancestors shaped our intellect through accelerating cycles of evolutionary feedback.' In other words, culture has been a fundamental driving force mediated by its co-evolution with genes. In this respect, I was surprised not to find any mention of epigenetics in the index, as this deals with gene expression shaped by lifestyle and therefore culture. It also seemed to me that the author has not fully absorbed the implications of Gaia theory articulated by Lovelock and Margulis where organisms and environment are closely intertwined rather than the latter exerting selection pressure on the former to adapt in certain specific ways. This systems way of thinking has yet to permeate biology.

The two parts address the foundations of culture in terms of copying, imitation, innovation and creativity, then evolution of the mind, the need for accuracy in social transmission, the origins of language and the foundations of cooperation. There is a fascinating chapter on the evolutionary roots of the arts, especially rhythm and dance. We have enormous adaptive plasticity, which we are now coming to appreciate also in relation to the brain. The argument for the culture drive hypothesis is entirely convincing in my view, and nicely illustrated in a diagram on page 129 where one can appreciate the feedback loop between high fidelity copying and the evolution of larger brains. Agricultural settlement is another key staging post enabling the development of civilisation and more specific shaping of the environment to human use. This effectively creates a congenial niche as well as an upsurge in innovation and greatly increased population; as we know, however, each advance brings its own corresponding challenges. Settlements provide new opportunities for cooperation - including trade - but also for rivalries. In our current situation, it has become crucial to enhance our capacity for cooperation on a larger scale beyond the nation state. These thoughts were developed by Kropotkin and others in terms of mutual aid, a feature also emphasised by Margulis and more recently by Elisabet Sahtouris. The author remarks that the scale and complexity of human cooperation is unprecedented, but we now need to take things to the next stage, and this book provides the necessary evolutionary background and understanding.