The World Before Us: how science is revealing a new story of our human origins

After decades of slowly piecing together the puzzle of our human origins, the last ten years have seen a gigantic leap forward in our knowledge, spurred by advances in aDNA (see CA 338), radiocarbon dating, and other areas of archaeological science. This new book by Tom Higham draws all of these recent discoveries together into a comprehensive, yet engaging account of how we came to be human and of the close relatives we lost along the way.

As the Director of the Oxford Radiocarbon Accelerator Unit (ORAU), Tom has been at the forefront of some of the biggest of these advances – leading the way in compound-specific dating (see CA 336), which has allowed for more precision in radiocarbon-dating particularly old organic samples, and helping to revolutionise the timeline for Denisovans and Neanderthals. His experience and love of the topic shine through, drawing readers in with his excitement about specific discoveries and technological advances.

Over the course of the book, Tom transports us back into the distant past, first to our earliest origins in Africa. Some previous narratives of our route ‘out of Africa’ have been problematic, over-simplified for the public to the point that they have been used to help reinforce stereotypes of a simple linear progression from the ‘primitive’ to the ‘evolved’. In this book, though, the complexities of the ‘out of Africa’ models (as there were at least two separate diaspora events) are highlighted, demonstrating that evolution is not a one-way street, but instead a complex maze of tree branches. This section, as well as subsequent chapters, also does a brilliant job of emphasising that human evolution is a story of all of our hominin ancestors, because to understand Homo sapiens’ success as a species we also have to understand why the many other branches flourished and then died out.

Emphasising this point, other chapters cover some of our non-African relatives from the well-known Neanderthals to the tiny Homo floresiensis, popularly known as ‘Hobbits’ and only found on the Flores island of Indonesia. The chapters on the Denisovans (a hominin that flourished in eastern Asia and which was contemporary to Neanderthals and Homo sapiens) and, in particular, the identification of them as a new, separate species are some of the most compelling in the whole book. As part of the team that has been working for the past couple of years in Denisova Cave, where the new hominin species was first found, Tom’s in-depth knowledge of the research involved paints a vivid picture of discovery, transporting the reader to the buzzing atmosphere of the laboratory as the researchers slowly realised what they had found.

Interspersed between the chapters on particular hominins are ones focused on the technological advances that have made these discoveries possible. Tom does a good job of synthesising what can be quite complex scientific jargon into an easily digestible read, although complete novices to the field might struggle a bit with some definitions. Perhaps unsurprisingly, given it is his area of expertise, the chapter on radiocarbon dating is particularly detailed and makes for a great lay introduction to the topic, including the complicated Bayesian modelling that has become so crucial for accurate dating analysis (see CA 259).

Inevitably for a book that covers such a large range of topics, some sections are quite brief, only touching on the highlights. As a reader, this can leave you yearning for more information. The book is also slightly skewed towards areas that Tom has the most knowledge of, with more attention and detail given to the Denisovans and radiocarbon dating than to other hominins and scientific techniques. This lack in some areas, though, allows for a wealth of details in others, giving Tom space to tell more first-hand stories that give the book a very personal touch. Overall, the breadth of topics covered is remarkable, serving as a brilliant introduction to our current state of knowledge of where we as humans came from and who helped us along the way.

The World Before Us: how science is revealing a new story of our human origins, Tom Higham, Viking Press, £20, ISBN 978-0241440674.
Review by KK.