Narrator: In 2012, under a drab city council car park in Leicester, England, archaeologists unearthed a skeleton. The bones were twisted by a severely curved spine and marked by the brutal wounds of battle, including a fatal blow that had sliced away part of the skull. Historical records suggested this might be the long-lost grave of King Richard III, the last English king to die in combat, but for over 500 years, his final resting place was a mystery. How could anyone be sure? The answer came not from a dusty chronicle, but from the king’s own DNA, extracted from his teeth and compared to that of his living relatives.

This remarkable discovery encapsulates the core argument of Adam Rutherford's groundbreaking book, A Brief History of Everyone Who Ever Lived. It posits that our DNA is not just a biological blueprint; it is the most detailed historical document ever written. It is an epic poem, passed down through millennia, that tells the true, unvarnished story of our species—a story of migration, sex, war, and survival that is far more complex and interconnected than we ever imagined.

Narrator: The traditional image of human evolution—a linear march from stooped ape to upright modern human—is a comforting but deeply misleading fiction. The reality, as revealed by ancient DNA, is a messy, tangled web of inter-species encounters. For much of our history, Homo sapiens were not the only humans on the planet.

The story of this revelation begins with the work of geneticist Svante Pääbo, who achieved what was once thought impossible: sequencing the genome of a Neanderthal. When he compared this ancient genetic code to that of modern humans, he found undeniable proof of interbreeding. People of non-African descent today carry, on average, around 2% Neanderthal DNA. This means that tens of thousands of years ago, our ancestors met, and had children with, their evolutionary cousins.

The story gets even more complex. In a Siberian cave, scientists found a tiny fragment of a finger bone and a tooth from an entirely new type of human, now known as the Denisovans. They were not Neanderthals, nor were they modern humans. Yet, their DNA also lives on in us today, particularly in the populations of Melanesia and parts of Asia. Rutherford explains that our ancestors were both "horny and mobile," and wherever they went, they mixed. The analysis of the Denisovan genome even hints at a "ghost population"—another, even more ancient human species that interbred with them, a group we only know from the spectral echo they left in the DNA of another extinct human. Our family tree is not a tree at all; it’s a dense, interwoven thicket.

Narrator: If our deep past is a story of inter-species mixing, our more recent history is one of constant migration and replacement. No modern population is a pure, unbroken lineage from ancient times. Instead, we are all mosaics, our genomes assembled from the contributions of successive waves of migrants.

Rutherford uses the genetic history of Europe as a prime example. For a long time, it was debated whether agriculture was a cultural idea that spread or if it was brought by migrating farmers who replaced the local hunter-gatherers. Genetics has settled the debate. Modern Europeans are a blend of at least three major ancient populations. First came the indigenous hunter-gatherers, like an 8,000-year-old man found in Luxembourg whose genes show he had dark skin and blue eyes. Then, around 7,500 years ago, a wave of early farmers swept in from the Near East, bringing with them not only agriculture but also genes for lighter skin. Finally, a third group, the Yamnaya pastoralists from the Russian steppes, migrated into Europe around 5,000 years ago, bringing horses, the wheel, and possibly the precursor to Indo-European languages.

This process of migration and mixing is not unique to Europe. It is the story of everyone, everywhere. The genetic map of the British Isles, for instance, doesn't show a clear divide between "Celts" and "Anglo-Saxons." Instead, it reveals a complex tapestry woven from Picts, Angles, Saxons, Vikings, and Normans, with no single group ever completely wiping out the others. Our identities are layered, and our DNA is the archive.

Narrator: Evolution is not just about adapting to climate or landscape; it is also a relentless arms race against disease. Major pandemics act as powerful engines of natural selection, culling those with susceptible genes and favoring those who, by chance, have a genetic advantage. The scars of these ancient battles are still visible in our DNA today.

The most dramatic example is the Black Death. In the mid-14th century, the bacterium Yersinia pestis killed as much as half the population of Europe. By extracting DNA from the teeth of plague victims buried in mass graves, scientists have been able to sequence the genome of the very pathogen that caused the pandemic. But more profoundly, they have seen its impact on our own genome. The plague created an intense selective pressure on the human immune system. People with certain variations in their immune-related genes were more likely to survive and pass those genes on.

As a result, modern Europeans—and other populations like the Roma, who were in Europe at the time—show a distinct genetic signature. Their immune systems have been shaped by the legacy of the plague. This is a stark reminder that history is not just something that happens to us; it becomes a part of us, written into our biological code.

Narrator: Perhaps the most powerful and controversial revelation from modern genetics is its complete demolition of the concept of biological race. The categories we use to define race—black, white, Asian—are social constructs that have no meaningful basis in our DNA.

This idea was first quantified in 1972 by geneticist Richard Lewontin. He analyzed variation in blood group genes across different global populations and made a landmark discovery: about 85% of all human genetic variation exists within any single population, for example, among the French. Only a tiny fraction of the remaining 15% accounts for the average differences between populations, such as between the French and the Japanese. In other words, two random people from Nigeria are likely to be more genetically different from each other than one of them is from a random person in Norway.

The physical traits we associate with race, like skin color, are biologically superficial. They are recent adaptations to local environments, driven by factors like UV radiation levels, and they represent a minuscule portion of our overall genetic makeup. Rutherford argues that while racism is undeniably real, race itself is a fiction. The beautiful irony of genetics, a field once co-opted by the eugenics movement to justify racial hierarchies, is that it has ultimately provided the most definitive evidence that race does not exist.

Narrator: A common question is whether humans are still evolving. The answer, Rutherford asserts, is an unequivocal yes. We are a species not of mutants, but of constant mutations. However, the forces driving our evolution have fundamentally changed.

Rutherford recounts being asked by a TV producer when humans would evolve to fly. His answer was that we already have. We didn't evolve biological wings; we invented airplanes. Our "superpower" is our massive, creative brain, which has allowed us to manipulate our environment and extract ourselves from many of the traditional pressures of natural selection. Medicine saves people who would have once died from infection. Agriculture provides a steady food supply. We have, in effect, changed the rules of the evolutionary game.

But evolution continues. Instead of being driven purely by survival of the fittest in a natural environment, it is now shaped by culture, technology, and medicine. Studies of long-term genealogical records, like those in Finland and Framingham, Massachusetts, show that traits related to reproductive success are still being selected for, even in modern societies. Our genomes are accumulating new mutations at a rapid rate, many of them arising in just the last 5,000 years. We are not the end point of evolution; we are a transitional species in a story that is still unfolding.

Narrator: The single most important takeaway from A Brief History of Everyone Who Ever Lived is that our DNA tells a story of radical interconnectedness. We are one, sprawling, surprisingly recent human family. The divisions we erect—based on nation, ethnicity, or race—are social fictions that crumble when confronted with the biological reality of our shared ancestry. Everyone is a mix, and our pedigrees intertwine constantly as we look back in time.

The book leaves us with a profound challenge to our sense of self. We are each utterly unique, the product of a 4-billion-year-long chain of cosmic and biological happenstance. Yet, we are also fundamentally the same, carrying the history of everyone who ever lived within our cells. If our genes tell a story of constant mixing, migration, and shared origins, how can we continue to justify the divisions that cause so much conflict in the world?