Although many words have been written attempting to show the unity of the human species, Steve Olson makes yet another attempt. He feels the need is there to be met. Instead of basing his effort on philosophical or moral grounds, he turns to our genetic record to make his point. It's a valid quest using unimpeachable methods and Olson presents it well. Some of the material, such as Wilson and Cann's "mitochondrial Eve" may be a bit shopworn, but it's an essential element of Olson's scenario. He builds his structure carefully and solidly, so a bit of used material isn't out of place. After all, he's not attempting any new, revolutionary concept in this book. He merely wishes to displace old, traditional ideas with a new reality.
Given the entrenched thinking about "race" in human cultures, calling Olson's task daunting is grievous understatement. The human diaspora from Africa he traces reaches across 150 millennia. Unlike most other species, humanity developed at an astonishing rate. Tracing genetic changes with humans migrating across the planet, not always in one direction is staggeringly difficult. Olson struggles, usually successfully, to reconcile the paleoanthropological finds with genetics research. He demonstrates the likely origins of the Chinese, Europeans, Australian and Western Hemispheric Aborigines. One subset of our species, the Jews, receives some special attention.
Olson recognises that much of the information he addresses is "highly contentious", but he bravely sets out to reconcile the views of many researchers. He examines in some detail, for example, hotly disputed notions about linguistic evolution. Given that the human population at the beginnings of language was already "on the road", his own description of language origins seems a bit thin. It would be unfair to fault him for this section, however, particularly since his aim isn't to prove or disprove any of the theories, but to use linguistic evolution as a metaphor. A full analysis of the topics in historical linguistics would double the size of the book. Readers interested in the topic should start with Olson's bibliography and keep reading.
Does Olson succeed in his quest? With the advances made in genetic analysis over the past generation, the origin of our species in Africa is now beyond dispute. Whether there's been enough time for local populations to form genetically distinct sub-species of Homo sapiens, Olson deftly refutes. There's been far too much intermingling and interbreeding to establish the kinds of races birds have done. That cultural ties keep groups with some identifiable physical traits such as the epicanthic folds of some Asian peoples doesn't justify labelling them with racial identities. A broadening of marriage traditions would quickly blend out the trait, as it already has in some areas.
Olson has performed a monumental task in defining our species. He covers the globe over an immense time span. He traces, as best he can with current evidence, the various tracks our ancestors took in occupying the planet. There's little doubt he's built a solid case for our identity as a single, if widespread, species. He helps his theme with some useful maps and other diagrams. Clearly our common ancestor denies the notion of "separate races".
On the other hand, why did he feel the need to make this effort. Clearly, "race", whether or not biologically valid, is a strong element in human thinking. Why this should be doesn't appear to be something we can identify through genetic analysis. The cause is ultimately, as Olson tentatively concedes, cultural. Bring up your children to hate someone identifiable, and they likely will do so. In Hawaii, likely the planet's most ethnically blended society, intermarriage, mixed schools and churches and full job opportunity, still has not shed divisions among its people. Olson would like his book to help overcome those divisions. It isn't likely to happen unless every human alive reads this book. And accepts his conclusions. [stephen a. haines - Ottawa, Canada]