Where did we come from?

In a glass case at eye level lies a human skeleton — long bones laid out in order, a ribcage fanned open, a skull tipped on its side, the whole of a person reduced to the parts that outlast us. On the wall beside it, a panel poses the only question a display like that can really be about. I stood in front of it long enough to copy it down.

“Modern humans evolved in Africa around 200,000 years ago. Scientists calculate there were then two waves of migration out of Africa, one around 120,000 years ago and another about 60,000 years ago … all non-Africans are largely or entirely descendants of those people in the second wave. The first-wave pioneers died out somewhere in the Middle East … But by 13,000 years ago our species was established in regions as far apart as Australia and South America.” — museum wall panel, “Where did we come from?”

It is a good, honest summary — of the science as it stood perhaps fifteen or twenty years ago. That is the quiet thing about a museum label: it freezes a field at the moment the panel was printed, and then the field keeps moving. But it also answers only a thin slice of a much older question. Pull the camera back and where did we come from runs all the way down: past our species, past our genus, past the first animals, to the first living cell — and, if you keep going, to the beginning of the universe itself. This piece follows that whole arc, with the evidence linked as it appears, so you can check each claim at its source rather than take it on my word. And where the hard science genuinely rhymes with it — only there — I set it beside the oldest written telling we have.

Before us: the first cells

Begin at the bottom. The universe began about 13.8 billion years ago; our Sun and Earth condensed from a later generation of stellar debris roughly 4.54 billion years ago. The young Earth was violent, but not for long: crystals of the mineral zircon from the Jack Hills of Western Australia show there was already liquid water at the surface some 4.4 billion years ago, far earlier than anyone once thought. The stage for life was set almost as soon as there was a stage at all.

And life did not wait. Every living thing on Earth — every bacterium, mushroom, redwood and reader — descends from a single population called LUCA, the last universal common ancestor. A 2024 analysis of the molecular clock places LUCA at around 4.2 billion years ago, already a surprisingly complex cell. The oldest direct physical traces are not far behind: layered microbial structures (stromatolites) from Greenland dated to about 3.7 billion years, contested tube-and-filament microfossils in Canada that may be as old as 3.77–4.28 billion years, and unmistakable signs of microbial life in 3.5-billion-year-old hot-spring deposits — life on land almost as early as life at all. There is even a hint of biological carbon locked inside a 4.1-billion-year-old zircon.

How non-living chemistry first crossed into life — abiogenesis, whether at hydrothermal vents, in tidal pools, or by way of a self-copying “RNA world” — remains genuinely unsolved, and I won't pretend otherwise. But that it happened early, and in water, is about as well supported as deep-time science gets. The whole rest of this story — us included — is a single unbroken thread of copying that runs back to that first cell. The timeline below is the whole span at a glance.

An older telling

Long before any of this could be measured, the same question got its most famous answer in the opening lines of Genesis. It is fashionable to treat that account and the scientific one as combatants; I think that is a category error on both sides, and it is worth being precise about exactly where they touch and where they do not. Read for chronological arithmetic — a universe a few thousand years old, made in six 24-hour days — the text simply loses to the dating, and I am not going to pretend the numbers agree when they flatly do not. But read for sequence and claim, several points genuinely rhyme, and only those I'll put beside the evidence:

• There was a beginning at all. “In the beginning…” asserts a first moment for everything. For most of the twentieth century science assumed an eternal cosmos; it was a genuine surprise when the evidence converged on a universe with a finite age and a beginning. On the bare fact of a starting point, the two now agree.
• Life came from the waters. Genesis has the waters “teem with living creatures” before the land does. The hard science likewise puts the origin of life in water — ocean, vent or hot spring — long before anything walked.
• Humanity arrives last. In the text, people come at the very end, after everything else. In the fossil record, anatomically modern humans are likewise the latest arrival, at the thin top edge of the timeline above.
• Made of the ground. Genesis forms the human “from the dust of the ground”. We are, literally: the carbon, oxygen, nitrogen and phosphorus in every cell are ordinary Earth chemistry, and the heavier atoms among them were forged in earlier stars. Dust, quite exactly.

None of that is proof of anything, and I don't offer it as such — resonance is not measurement. What it does show is that the two accounts are answering different questions: one asks how and dates it, the other asks why and means it. Notably, the tradition never actually required the short clock — long before geology it read the “days” as epochs, on the licence of texts like Psalm 90:4 and 2 Peter 3:8, “a thousand years… like a day.” With that settled, the rest of this piece stays with the measurable thread.

From one cell to many

Having life by ~3.7 billion years ago, Earth then did almost nothing with it for an extraordinarily long time. For roughly two billion years the planet was a world of single cells. The first great turning point was chemical: some microbes learned to photosynthesise, and their waste product — oxygen — slowly poisoned and then remade the atmosphere in the Great Oxidation Event around 2.4 billion years ago. Only then did complex cells with nuclei (eukaryotes, our own kind of cell) take hold, with good fossils by about 1.6 billion years ago.

Animals came late and then all at once. Large, soft-bodied Ediacaran creatures appear around 575 million years ago; then, in a geological eyeblink around 539 million years ago, nearly every major animal body plan we know bursts into the record in the Cambrian explosion. From there the familiar reel runs fast: fish, the move onto land, the age of dinosaurs, and then the asteroid of 66 million years ago that ended it — clearing the stage on which mammals and the first primates radiated. Our own branch split from the chimpanzee lineage roughly seven million years ago; the genus Homo appears by about 2.8 million years ago; and Homo erectus had already walked out of Africa and across Asia by 1.8 million years ago. Which finally brings us to the sliver of time the museum panel is actually about.

Older than the label says

Start with the birthday. “Around 200,000 years ago” was, for a long time, the textbook figure — anchored to the Omo Kibish fossils from Ethiopia, first dated to about 195,000 years. Then in 2017 a team re-examined a site called Jebel Irhoud in Morocco and dated a cluster of Homo sapiens-like remains — a face strikingly like ours, on a braincase still a little archaic — to roughly 300,000 years ago. The find did two things at once. It pushed the origin of our lineage back by a hundred millennia, and it moved the cradle: not a single Garden-of-Eden valley in East Africa but a process spread across the whole continent, with populations mixing and diverging over a vast span of time. (Omo Kibish, for its part, was itself re-dated in 2022 to at least 233,000 years, tugging in the same direction.)

So the honest modern answer to “when did we evolve?” is not a date but a range with a fuzzy leading edge: our anatomy assembled gradually across Africa over something like the last 300,000 years, and “fully modern” is a line we drew afterwards, not one nature marked. The timeline below zooms in on that final sliver.

Many doors, mostly closed

The panel's cleverest move is the idea of waves — that we left Africa more than once, and that only the last departure has living descendants outside Africa. That framing has aged well. What has changed is how many doors we now know our ancestors tried, and how early.

The panel dates the first wave to about 120,000 years ago, and there is good evidence for people at exactly that time: the Skhul and Qafzeh caves in what is now Israel held anatomically modern burials from roughly 90,000 to 120,000 years ago. But the door had been opened earlier still. In 2018 a fossil upper jaw from Misliya Cave, also in Israel, was dated to between about 177,000 and 194,000 years — pushing the earliest known human presence outside Africa back by tens of thousands of years. There are hints of modern humans in Arabia around 85,000 years ago, and contested claims of teeth in southern China older still. The out-of-Africa turnstile, it turns out, was spinning for a very long time.

And here the panel's melancholy little phrase — the first-wave pioneers died out — holds up. Genetically, these early excursions left almost no trace in people alive today. Whether they perished, retreated, or were simply swamped, the Skhul–Qafzeh and Misliya populations are, as far as our DNA can tell, dead ends. The ancestry of every non-African alive today funnels back through a single later dispersal, usually put at around 50,000 to 60,000 years ago — the “second wave” the label rightly singles out. On that number, the panel and the genome agree.

We did not travel alone

The single biggest thing the old panel could not have said — because the evidence did not exist yet — is that the pioneers who left Africa walked into a world that already had people in it, and started families with them. In 2010 the first draft Neanderthal genome revealed that everyone outside Africa carries a sliver of Neanderthal DNA, on the order of 1.5 to 2 per cent. A companion discovery the same year, from a single finger bone in a Siberian cave, introduced an entirely new human population — the Denisovans — known first from their genome and only later from a handful of bones and teeth.

The archaic inheritance is not spread evenly, and its pattern is a map of the journey. Neanderthal ancestry is found in every non-African population at roughly the same low level (a touch higher in East Asians). Denisovan ancestry, by contrast, is concentrated spectacularly in one direction: the peoples of New Guinea and Aboriginal Australians carry something like 4 to 6 per cent Denisovan DNA — a genetic fingerprint left by encounters somewhere along the long coastal road to Sahul. Recent work on the Neanderthal side has even pinned down when the main mixing happened: a narrow window around 47,000 years ago, shortly after the exit, in the Middle East or thereabouts — almost exactly where the panel says the first-wave pioneers died.

None of this fits on a wall panel from the 2000s, and it changes the emotional register of the whole story. We are not the last twig of a tree that shed every other branch; we are a mosaic, still carrying working genes from cousins who vanished forty thousand years ago — some of them, like the high-altitude adaptation Tibetans inherited from Denisovans, doing useful work in living bodies today.

The far shores came early

The line that has aged least well is the last one: by 13,000 years ago our species was established in regions as far apart as Australia and South America. Both halves of that sentence are now thought to be far too young.

Take Australia. The rock shelter of Madjedbebe in Arnhem Land was re-excavated and, in 2017, dated to about 65,000 years ago — not 13,000. Even allowing for the genuine controversy over that figure (some researchers favour a more conservative 50,000–55,000), the first Australians arrived tens of millennia before the panel's date. Reaching Sahul at all was an extraordinary feat: even at the lowest Ice-Age sea levels it required open-water crossings of tens of kilometres, the earliest evidence anywhere of humans deliberately going to sea.

The Americas have moved even more dramatically. For most of the twentieth century the “Clovis first” consensus held that people arrived only around 13,000 years ago — exactly the panel's number. That wall has fallen. Monte Verde in Chile pushed the date to about 14,500 years ago decades ago; and in 2021 a set of fossilised human footprints at White Sands, New Mexico, was dated to roughly 21,000–23,000 years ago, a result defended by independent methods in 2023. People were in the Americas during the coldest depths of the last Ice Age, thousands of years before the date on the wall.

The label and the latest

Set the panel's figures beside today's best estimates and a clear pattern jumps out. Almost every date has moved the same way — further back in time — and the two that moved most are the far shores, Australia and the Americas. The one number that barely budged is the one the panel got most right: the ~60,000-year dispersal that founded everyone alive outside Africa.

Where might it go?

If the question runs all the way down, it also runs forward. A common assumption is that human evolution has stopped — that medicine, comfort and culture have switched off natural selection. That is not what the genomes show. Reading DNA from ancient skeletons, researchers can watch selection working within the last few thousand years: on height, on immunity, on the ability to digest milk into adulthood — lactase persistence, which swept through dairying populations in Europe and Africa only after farming began. Evolution did not stop; it changed targets. What we eat, the diseases we crowd together to share, even the age at which we have children, are all still quietly editing the species.

What is genuinely new is that, for the first time in four billion years, one of the copied things can read and rewrite its own copying instructions. We now sequence genomes for the price of a meal and, since 2018, have crossed the line into editing the human germline — changes that pass to children. That turns evolution, in principle, from something that happens to a species into something a species might partly choose: an extraordinary power freighted with equally extraordinary ethical weight, and I'll flag clearly that everything past this sentence is informed speculation, not evidence.

Given that, the long-run shape is a fork. Down one path lies convergence: a globally mobile, interbreeding humanity blends, and regional differences that took tens of millennia to accumulate slowly wash together. Down another lies divergence: should we ever settle other worlds, small isolated founder populations under strange new pressures are exactly the recipe that produced new species in the past. And cutting across both is design — deliberate change by our own hand, faster than selection has ever worked. The diagram sketches the three.

Why the numbers keep moving

It would be easy to read all this as the museum getting it wrong. It is closer to the truth to say the museum got it right for its moment, and the moment passed. Three engines keep dragging the dates around, and all three ran hard in the years after that panel was printed.

The first is simply more digging: a single well-dated site — Jebel Irhoud, Misliya, Madjedbebe, White Sands — can reset a number the instant it is published, because in this field the oldest secure date wins, and there is always an older one waiting to be found. The second is better clocks: advances in dating methods, from luminescence to refined radiocarbon calibration, have let us read ages off sediments and footprints that older techniques could not touch. And the third, the real revolution, is ancient DNA — a technology that barely existed when the panel was written and has since let us read the genomes of the dead, discover whole human populations like the Denisovans from a fingertip, and watch our species interbreed with its cousins in something close to real time. It is the difference between reconstructing a journey from the bones left at the roadside and reading the travellers' own diaries.

Which is the quiet lesson standing in front of that glass case. The skeleton is permanent; the label is a draft. “Where did we come from?” has a stable answer in outline — a single thread of life running back nearly four billion years, out of Africa more than once, mingling with others as we went — and a moving answer in every particular, because we are still, right now, finding out. The best any panel can do is tell you the truth as of the year it was printed, and trust the visitor to know that the field kept walking after the sign went up.

Sources & notes

• The universe and the early Earth. The ~13.8-billion-year age of the universe from NASA / WMAP (consistent with the ESA Planck results); Earth's ~4.54-billion-year age from the U.S. Geological Survey; and evidence of surface liquid water by ~4.4 billion years from Wilde et al., Nature (2001) on the Jack Hills zircons, with possibly biogenic carbon in a 4.1-billion-year zircon in Bell et al., PNAS (2015).
• The origin of life. The ~4.2-billion-year estimate for LUCA is from Moody et al., Nature Ecology & Evolution (2024). Oldest physical traces: Nutman et al., Nature (2016) on ~3.7-billion-year Isua stromatolites; Dodd et al., Nature (2017) on putative 3.77–4.28-billion-year vent microfossils; and Djokic et al., Nature Communications (2017) on 3.5-billion-year hot-spring (land) life. How abiogenesis actually occurred remains unresolved.
• Oxygen, complex cells and animals. Lyons, Reinhard & Planavsky, Nature (2014) on the Great Oxidation Event (~2.4 Ga); Bengtson et al., PLOS Biology (2017) on ~1.6-billion-year eukaryotes; and Erwin et al., Science (2011), “The Cambrian conundrum,” on the ~539-million-year animal radiation.
• Mammals to hominins. O'Leary et al., Science (2013) on the placental-mammal radiation after the 66-million-year extinction; Brunet et al., Nature (2002) on Sahelanthropus (~7 Ma) near the human–chimp split; Villmoare et al., Science (2015) on the genus Homo by ~2.8 Ma; and Lordkipanidze et al., Science (2013) on Homo erectus at Dmanisi (~1.8 Ma).
• Oldest H. sapiens fossils. Jean-Jacques Hublin et al., “New fossils from Jebel Irhoud…,” Nature (2017), dating the remains to ~300,000 years; and the 2022 re-dating of Omo Kibish to at least ~233,000 years. Overview at the Smithsonian Human Origins program.
• Earliest exit from Africa. Israel Hershkovitz et al., “The earliest modern humans outside Africa,” Science (2018), on the Misliya Cave maxilla (~177,000–194,000 years); with the Skhul and Qafzeh burials (~90,000–120,000 years) as the classic “early wave.”
• Neanderthal and Denisovan ancestry. Richard Green et al., “A draft sequence of the Neandertal genome,” Science (2010); David Reich et al. on Denisovan admixture in Oceania (~4–6% in Papuans and Aboriginal Australians), American Journal of Human Genetics (2011). On the timing of Neanderthal gene flow (~47,000 years ago), see Iasi et al., Science (2024).
• Australia. Chris Clarkson et al., “Human occupation of northern Australia by 65,000 years ago,” Nature (2017), on Madjedbebe — noting the ongoing debate over the 65,000-year date.
• The Americas. Matthew Bennett et al., “Evidence of humans in North America during the Last Glacial Maximum,” Science (2021), on the White Sands footprints (~21,000–23,000 years), with independent dating support in Science (2023); and the earlier Monte Verde, Chile evidence (~14,500 years).
• Ongoing and future evolution. Mathieson et al., Nature (2015), “Genome-wide patterns of selection in 230 ancient Eurasians,” on recent natural selection in humans; and Tishkoff et al., Nature Genetics (2007) on the convergent evolution of lactase persistence. The “where it might go” section beyond this is clearly-flagged speculation.
• The older telling. Genesis 1:1, 1:20, 1:26–27 and 2:7, read for sequence and claim rather than chronology; on the long-standing non-literal reading of the “days,” Psalm 90:4 and 2 Peter 3:8. The concordances noted are on the fact of a beginning, life from water, humanity's late arrival and our elemental make-up; a literal young-Earth chronology is not supported by the dating and is not claimed here.
• General. The Smithsonian National Museum of Natural History Human Origins program and the Natural History Museum human-evolution pages give accessible, regularly updated overviews. Dates throughout are approximate and, in several cases, actively contested — this piece favours the order of magnitude over the last digit.