Following the clues: evolution as a detective thriller
Review by Stuart Barlow
It is fitting that Martin Brasier’s wonderful book has been published while we are celebrating the 150th anniversary of Charles Darwin‘s On the Origin of Species. He tackles a paradox that Darwin was unable to answer: the apparent lack of physical evidence of life from the pre-Cambrian period, emerging from geological records during the nineteenth century. Fossils of major and diverse animal groups seemed to appear abruptly and fully formed in the Cambrian period, in what is described as the ‘Cambrian explosion’, an event which took place some 530 million years ago.
Brasier’s description of what he and other paleobiologists have been doing to open up this “lost world” reads like a good old fashioned ‘who done it’, or as Brasier puts it a ‘how done it’! Following the twists and turns of this story will certainly tax those ‘little grey cells’ as you trace the evolutionary threads from Fallotaspis to Chancelloria, onto Aldanella and Maikhanella. You will be taken on a tour of the world’s hottest fossil beds in North America, Siberia, China, Mongolia, Morocco, the north of Scotland and even the Charnwood Forest in Leicestershire, to track down elusive clues to this mystery. It even has a whiff of a cold war drama when the organisers of a meeting of paleobiologists in 1983, in a country house outside of Bristol, were kept on their geopolitical toes by teams from Moscow, Siberia, China, North America, Australia and Europe jockeying for position, as each claimed to hold the key to explaining what had happened across the Pre-Cambrian/Cambrian boundary.
Finally, Brasier, like all good detectives, draws the threads of the story together to expose the answers you have being trying to guess from the clues liberally spread through out the book. Brasier explains how fossils in pre-Cambrian rocks, were better preserved than later fossils but they were smaller and are visible only with microscopes and different instruments. It appears that the Cambrian explosion did occur as a qualitative change as trilobites and other arthropods emerged only at the start of the Cambrian period.
But why is this important? As Brasier points out, Darwin’s big idea was that “evolution by natural selection is the thing that explains all life and biology”. His ideas took the world by storm, shaking the establishment to its core - giving new shape to the dreams of ordinary working people and society at large. Darwin’s theory of evolution revolutionised the way we see nature and our place in it, defining the nature of the human condition. In the view of Karl Marx’s collaborator, Frederick Engels:
Darwin dealt the metaphysical conception of Nature the heaviest blow, by his proof that all organic beings, plants, animals, and man himself, are products of a process of evolution going through millions of years.
Proof, as Engels put it, that nature works dialectically.
This book provides an insight into the new 20th century science of paleobiology, or geobiology as it is sometimes known, which brings together earth science (paleo) with natural science (biology). The biochemical analysis of DNA and RNA has shed new light on Pre-Cambrian organisms.
Almost by accident, Brasier’s book shows another side of the paleobiologist’s life. The pressure to produce results, as a response to the increasing demands of funding, can lead to the “Mofaotyof” principle – my oldest fossils are older than your oldest fossils – where scientists exaggerate their finds from limited amounts of material so they can gain publicity for their institutions. Leading to what Brasier describes as “exchanging one set of creation myths for another”. Clearly academia needs to be rescued from the grip of market forces and converted into not-for-profit organisations.
In the end, I can whole-heartedly recommend Darwin’s Lost World as a thoroughly good read and a glimpse into the enduring importance of Darwin’s ideas. A low-price paperback version would make it even more accessible.
26 February 2009