What does it mean to be human?

At its heart, anthropology is driven by a single, profound question: what does it mean to be human? I was drawn to the study of anthropology as I was fascinated by human behaviour and how this influenced history. I soon became focused on the influence of evolution on the human psyche and how this ‘dictated’ our behaviour.

As a student, however, I soon discovered that there were many ‘anthropologies’.  The path taken to answer the question of what it means to be human can look remarkably different depending on which anthropology you are looking at; for example, the study of anthropology in the USA and in Britain, while sharing common ancestors and a passion for understanding humanity, has evolved into two distinct traditions, each with its own foundational structure, core focus, and historical drivers. This divergence shapes not only how the discipline is taught in universities but also the very questions it seeks to answer.

In the United States, anthropology is traditionally a "holistic" enterprise. Following a four-field approach championed by the influential Franz Boas, it brings together cultural anthropology, biological/physical anthropology, archaeology, and linguistic anthropology under one intellectual roof. The goal is to understand humanity in its entirety, integrating evidence from our bodies, our languages, our past, and our beliefs to explore the why of human diversity. An American anthropologist might study everything from ancient pottery to primate behaviour and human genetics.

Across the Atlantic, British anthropology—more precisely termed social anthropology— has charted a different course. Closer in spirit to sociology, its focus is trained intently on the intricate mechanics of society. Born from research within the British Empire, its primary concern has been to understand how social structures, kinship systems, and institutions function and are maintained. This tradition emphasises deep, immersive ethnographic fieldwork, pioneered by Bronislaw Malinowski, to grasp the complex web of relationships that bind communities together.

Social anthropology, therefore, is tied to understanding how cultures operate, whereas the physical side of anthropology attempts to understand evolution through palaeontology, biology and archaeology. This blog has been triggered by a birthday present. I was given Tom Higham’s book, The World Before Us, which reminded me of the huge advances that have been made in physical anthropology.

For most of our history, we believed we were alone, and the story of human origins was told as a linear ascent, a triumphant march where our species, Homo sapiens, emerged from Africa and simply outcompeted all other, ‘lesser versions’ of humans until only we remained. It was a clean, simple narrative of survival of the fittest. That simple story, however, is not just incomplete but now appears to be plain wrong. Higham’s central thesis is that a recent revolution in archaeological science—powered by ancient DNA analysis and advanced dating techniques—has torn up the old narrative and replaced it with something far more complex, intimate, and perhaps unsettling. We now know that we were not always alone, and that the survival of our species was not a foregone conclusion, but a nuanced outcome shaped by chance, climate, and the very DNA we inherited from the other humans we met along the way.

The traditional view painted a world where Homo sapiens were the sole protagonists. But modern research forces us to see the prehistoric world as a crowded stage. Fifty thousand years ago, our planet was home to at least four other distinct human species. There were the familiar Neanderthals, of course, but also the mysterious Denisovans, known only from a sliver of bone found in a Siberian cave. There was the diminutive Homo floresiensis, the "Hobbit" of Flores, and the recently discovered Homo luzonensis from the Philippines. The book’s thesis insists that our history is not one of simple replacement, but one of profound coexistence and admixture. We did not simply eradicate them; we lived alongside them, and as we now know, we mixed with them.

The "hard evidence" of bones and stones is no longer sufficient on its own to tell the full story. A new kind of archaeology has emerged, one that extracts history from the invisible world of molecules. By using ancient DNA to pull genetic information from fossils that are tens of thousands of years old, and even from the very dirt of cave floors where ancient humans once walked, scientists can now detect the presence of species that left no skeletal remains behind. The discovery of the Denisovans stands as the ultimate proof-of-concept for this argument. An entirely new branch on the human family tree was identified not from a grand skeleton, but from the DNA of a single, unassuming finger bone. It was a discovery that would have been impossible just a generation ago, and it fundamentally proves Higham’s point: that a hidden world of human interaction was waiting to be revealed by science.

The most profound implication of this new science is the thesis’s culminating idea: we are a hybrid species. The extinction of the Neanderthals and the Denisovans as distinct populations does not mean they are truly gone. Through interbreeding, their genes flowed into the Homo sapiens gene pool and have persisted down through the millennia to us. Higham argues that this is not a trivial or romantic footnote to our history; it is a significant part of our biological reality. This genetic inheritance has tangible, measurable effects on modern human health and survival. The ability of modern Tibetans to thrive in the low-oxygen conditions of the high Himalayas is a gift from their Denisovan ancestors. Conversely, our risk for certain conditions, like Type 2 diabetes, can be traced back to Neanderthal genes. We are, quite literally, walking mosaics, our very selves a product of this ancient, intertwined world.

Finally, woven through this scientific detective story is a subtle but powerful argument for the role of contingency. In Higham’s telling, the survival of Homo sapiens was not an inevitable victory of a superior model. It was a far more precarious affair, shaped by luck and circumstance. For thousands of years, we shared the planet with these other humans, and the outcome was anything but certain. Our eventual dominance was likely tipped by a combination of our own capabilities, the advantageous genes we acquired from our cousins, and perhaps a greater resilience to a changing climate that pushed other species to the brink. We survived, but the book suggests it could easily have been a different story.

In the end, the thesis of The World Before Us is a powerful and humbling one. It asserts that to truly understand ourselves—Homo sapiens—we must first understand the world that came before us. It was a world populated by other humans whose lives, deaths, and genetic contributions are now being illuminated by the very science they made possible. They are not just footnotes in our history; they are a part of our present, their ancient world forever encoded in our DNA.