British geneticist Adam Rutherford is one of the country's great science communicators, an alumnus of Nature whose work we've celebrated here for many years; with his second book, A Brief History of Everyone Who Ever Lived, Rutherford reveals how the century's astounding advances in genetic science reveal just how little we understand about our genes -- and how our ideas about race and heredity are antiquated superstitions that reflect our biases more than our DNA. (See the bottom of this post for an important update about the upcoming US edition!)

At its worst, scientific debunking can be a kind of grim and humourless exercise in which a distinguished scientist explains how you've got it all wrong and scientists really know very little about a subject that you thought they'd had nailed down, and you should really be couching all your statements about the truth of the world in so many caveats that no statements can be discerned. That's not Rutherford's style.

Rutherford is one of the most sprightly and delightful science communicators in the field, a writer who uses footnotes for comic relief with skill not seen since the heyday of Douglas Adams, whose delight in language is matched by a wonder for the things science does teach us, who uses that delight to shine a glorious light on marvels even as he pitilessly illuminates the often harmful bullshit that the public has been told to believe about what genetics says about them.

Rutherford's thesis is that the more we learn about our genome, the more we learn about ourselves as a species — and the less we can know about ourselves as individuals. Population-wide genetic sequencing reveals truths about how closely related we all are (we're all cousins, and much closer ones than you probably suspect), how little our alleged "race" predicts about us, and how much of what we think of as "heredity" is more complicated and weirder than we've been led to believe.

Brief History challenges our understanding of what a species is, and what our species is, as the extraction of genomes from living specimens and ancient fossils reveals that humans, neanderthals and other cousins co-existed for unimaginably long timescales, and crossed and re-crossed their DNA. Contrast this profligacy and its outcomes with the closely guarded, inbred "noble blood" of Europe's royal houses, whose belief in their own genetic superiority led them to breeding experiments that produced insane, pain-wracked monarchs whose reigns were marred by seizures, delusions, and violent outbursts that only ended when the lines' terminal specimens could no longer breed.

The upshot of all this is that those 23-and-me-style genetic "analyses" that you can send away for are fairy tales, describing genetic propensities that are more likely to be statistical ghosts than real phenomena, and family histories that rely on categories ("Germanic," say) that have no objective basis in reality.

But while your individual sequence won't tell you much about who you are and where you came from, these corpuses — especially the public interest ones gathered by research scientists and not private, woo-peddling companies — are revealing an astonishingly detailed picture of humanity's pre-history.

Genetics and heredity have a checkered past: at its best, our study of DNA has given us breakthroughs in fighting disease, breeding better crops, and learning about our common destiny. At its worst, it has provided demagogues with scientific cover for racist rhetoric and violence. As a new era of data-driven genomics dawns, Rutherford is determined to rescue it from being turned to evil ends and elevate it to a pedestal from which it can teach us how much we all share with one another.

A Brief History of Everyone Who Ever Lived [Adam Rutherford/Orion]

Update: Jennifer from The Experiment publishing writes, "I wanted to let you know that we're publishing a US edition on October 3. Even better, it has an entirely new chapter on the genetic history of the Americas and a brand new foreword by Siddhartha Mukherjee."