Deep Time: A Narrative Timeline of Human Evolution
From the first upright walker to the first city-dweller — and the civilizations we've lost along the way.
"The most beautiful thing we can experience is the mysterious. It is the source of all true art and science." — Albert Einstein
This timeline is not merely a list of dates. It is the story of a species — Homo sapiens — emerging from the African savanna, spreading across every continent, building empires, forgetting them, and building again. Alongside the triumphs are the losses: cities whose names we barely remember, empires whose languages we cannot read, peoples whose songs are gone forever.
What follows is both a map and a meditation on the human journey.
─────────────────────────────────────────
THE DEEP PAST: BEFORE HUMANITY
─────────────────────────────────────────
◆ 13.8 Billion Years Ago — The Big Bang
The universe begins. Space, time, matter, and energy emerge from a singularity. For billions of years, there is nothing that could be called life.
◆ 4.54 Billion Years Ago — Earth Forms
A disc of gas and dust coalesces around a young star. The planet is molten, bombarded by asteroids, shrouded in toxic atmosphere. Nothing lives here yet.
◆ 3.7–3.5 Billion Years Ago — First Life
Stromatolites — microbial mats — emerge in shallow seas. They will oxygenate the atmosphere over the next two billion years, making complex life possible. The patience of evolution is staggering.
◆ 540 Million Years Ago — The Cambrian Explosion
Animal body plans diversify rapidly. Eyes, limbs, nervous systems appear. The ancestors of every living animal are represented here, in the ancient seas.
◆ 66 Million Years Ago — The K-Pg Extinction
An asteroid strikes the Yucatán Peninsula. Three-quarters of all species are extinguished, including the non-avian dinosaurs. Small, warm-blooded mammals survive in the shadows. One lineage will eventually produce us.
◆ 55–34 Million Years Ago — Primate Origins
The order Primates diverges from other mammals. Early prosimians give way to monkeys, then apes. The African continent is key: it will be the cradle of our lineage.
◆ 20–15 Million Years Ago — The Great Apes Diverge
The common ancestor of gibbons, orangutans, gorillas, chimpanzees, and humans walks (or swings) through ancient forests. Climate shifts will gradually reshape African habitats, forcing adaptations.
─────────────────────────────────────────
7 MILLION – 300,000 YEARS AGO: HOMININS
─────────────────────────────────────────
◆ ~7 Million Years Ago — Sahelanthropus tchadensis
Location: Chad, Central Africa
Status: Possibly our oldest known ancestor
The skull nicknamed "Toumaï" was discovered in Chad's Djurab Desert in 2001. Dating to approximately 7 million years ago, Sahelanthropus tchadensis sits at or near the base of the human family tree — the point at which our lineage diverged from that of chimpanzees.
What makes Toumaï remarkable is the combination of features: a small, ape-like brain case paired with facial features that suggest a more forward-facing skull, and — controversially — possible signs of upright walking inferred from the position of the foramen magnum (the hole through which the spinal cord enters the skull). If Toumaï walked upright, it rewrites our understanding of when bipedalism began.
What we know: Brain size ~350cc. Prominent brow ridges. Forest/woodland environment near an ancient lake.
What we don't know: Whether Toumaï walked bipedally. Whether it represents a direct ancestor or a side branch. Its relationship to Orrorin tugenensis (~6 mya, Kenya).
◆ ~4.4 Million Years Ago — Ardipithecus ramidus
Location: Ethiopia's Afar region
Status: Possible ancestor; walked upright but retained tree-climbing abilities
"Ardi" was published in 2009 after fifteen years of painstaking reconstruction. She stood about 120 cm tall and weighed ~50 kg. Her feet were grasping — useful in trees — but her pelvis suggests upright walking. She lived in a woodland environment, challenging the old "savanna hypothesis" that bipedalism arose purely as an adaptation to open grasslands.
◆ ~3.9–2.9 Million Years Ago — Australopithecus afarensis
Location: Ethiopia, Kenya, Tanzania
Status: One of the best-documented early hominins; probable ancestor of Homo
The most famous specimen is "Lucy" (AL 288-1), discovered in 1974. Her skeleton — 40% complete — confirmed bipedal locomotion beyond doubt. The Laetoli footprints in Tanzania (~3.7 mya), left in volcanic ash by A. afarensis individuals, show a distinctly human walking gait.
Lucy's brain was small (~400cc — roughly chimp-sized), but she walked upright habitually. She used tools only in the most rudimentary sense, if at all. Her social life remains mysterious, though the discovery of Selam (the "Dikika child," ~3.3 mya) suggests parental investment in young.
◆ ~2.8 Million Years Ago — Genus Homo Emerges
Location: Ethiopia
Specimen: LD 350-1 (mandible fragment)
The oldest known fossil assigned to genus Homo. The climate is shifting — Africa is becoming more arid, grasslands expanding. Hominins that can exploit new food sources, walk efficiently across open landscapes, and use tools will have an advantage.
◆ ~2.6 Million Years Ago — Oldowan Stone Tools
Location: Gona, Ethiopia
Technology: First recognizable stone tool industry
Sharp flakes struck from stone cores. These aren't fancy, but they're transformative. With Oldowan tools, hominins can access bone marrow (calorie-rich fat), process plant foods, and cut meat from carcasses. Diet diversifies; brains can grow larger, fed by better nutrition.
◆ ~2.0–1.8 Million Years Ago — Homo erectus / Homo ergaster
Location: Africa, then spreading into Eurasia
Brain size: ~900–1100cc (up from ~600cc in earlier Homo)
Homo erectus is a world traveler. By 1.8 million years ago, populations reached the Caucasus (Dmanisi, Georgia), Java (Indonesia), and eventually China. The "Turkana Boy" skeleton from Kenya (~1.6 mya) shows a tall, long-legged body plan adapted for walking and running long distances in open savanna.
Erectus likely used fire — though evidence for controlled fire is debated before ~1 million years ago. The Acheulean handaxe tradition, with its beautifully symmetrical teardrop shapes, suggests aesthetic sense as well as function.
◆ ~1.0 Million Years Ago — Controlled Use of Fire
Location: Wonderwerk Cave, South Africa
Evidence: Burned bone fragments, plant ash
Fire changes everything. Cooking breaks down proteins and starches, making more calories available. It extends the day (work and social time after dark). It provides warmth and protection from predators. Some researchers argue that cooking is what drove the final expansion of the human brain.
◆ ~600,000–300,000 Years Ago — Homo heidelbergensis
Location: Africa and Europe
Status: Likely ancestor of both Neanderthals (Europe) and Homo sapiens (Africa)
A large-brained, robust hominin that hunted big game cooperatively. Spears from Schöningen, Germany (~300,000 years ago) are masterpieces of prehistoric engineering — balanced throwing weapons that required planning, carpentry skills, and understanding of ballistics.
◆ ~300,000 Years Ago — Homo sapiens Appears
Location: Jebel Irhoud, Morocco
Brain size: ~1300–1400cc (modern range)
The oldest specimens assigned to anatomically modern humans were found at Jebel Irhoud, Morocco, in 2017. They are 300,000 years old — 100,000 years older than previously thought. Modern human origins are thus older, and possibly more geographically widespread in Africa, than the classic "Out of Africa" single-origin model suggested.
─────────────────────────────────────────
300,000 – 70,000 YEARS AGO: BEHAVIORALLY MODERN HUMANS
─────────────────────────────────────────
◆ ~200,000–100,000 Years Ago — Symbolic Behavior Emerges
Location: South Africa, Morocco
Evidence: Ochre use, shell beads, engraved patterns
At Blombos Cave (South Africa), ochre pieces engraved with geometric patterns date to ~75,000 years ago. Shell beads from Nassarius kraussianus shells were strung as jewelry. These are not survival tools — they are symbolic objects, markers of identity and group membership.
Language likely develops around this period, though it leaves no direct fossil record. The ability to communicate complex, abstract ideas — to tell stories, to discuss things that aren't present, to plan cooperatively — transforms social organization fundamentally.
◆ ~70,000 Years Ago — The Toba Catastrophe (Disputed)
Event: Supervolcano eruption in Sumatra
Possible effect: Near-extinction of human population (bottleneck)
The Toba eruption was one of the largest volcanic events in geological history, producing ~2800 km³ of magma. Some researchers argue it caused a "volcanic winter" that reduced global human populations to perhaps 10,000–40,000 individuals, creating a genetic bottleneck visible in modern DNA. Others dispute the severity of the impact on human populations. The evidence remains contested.
◆ ~65,000–50,000 Years Ago — Out of Africa Migration
Route: Across the Arabian Peninsula, into South Asia, East Asia, and Australia
Modern humans spread out of Africa in one or more waves. By ~65,000 years ago, they reached Australia (the Madjedbebe site). By ~45,000 years ago, they are in Europe, where they encounter the Neanderthals.
Crucially, modern humans did not simply replace other archaic human species — they interbred with them. Modern non-African humans carry ~1-4% Neanderthal DNA. Indigenous Australasians and Melanesians carry ~4-6% Denisovan DNA. We are hybrids.
◆ ~40,000 Years Ago — Upper Paleolithic Revolution
Location: Europe and beyond
Evidence: Cave paintings, figurines, musical instruments, complex tools
The Chauvet Cave paintings (France, ~36,000 years ago) and Altamira (Spain, ~14,000–36,000 years ago) demonstrate sophisticated representational art. The Venus of Hohle Fels (~40,000 years, Germany) is the oldest known figurine. Flutes made from bird bone and mammoth ivory date to ~40,000 years.
This is the full flowering of human cognition — the same capacity for art, music, story, and abstraction that we possess today.
─────────────────────────────────────────
12,000 – 3,000 BCE: THE AGRICULTURAL REVOLUTION AND THE FIRST CITIES
─────────────────────────────────────────
◆ ~11,000 BCE — The First Domestications
Location: The "Fertile Crescent" (modern Iraq, Syria, Turkey, Levant)
Species: Wheat, barley, lentils; sheep, goats, cattle, pigs
In the hills of the Zagros Mountains and the Levantine corridor, people begin to deliberately plant seeds and tend animals. This is not a sudden invention but a gradual intensification of relationships between humans and certain plant and animal species.
The consequences are enormous: permanent settlements, population growth, social stratification, surplus food, specialization of labor, and eventually — writing, taxation, and empire.
Göbekli Tepe (~9600 BCE, Turkey): Monumental stone pillars with carved animals, built by hunter-gatherers before agriculture. It challenges assumptions about what "complex society" requires.
◆ ~7000–5500 BCE — Çatalhöyük
Location: Central Anatolia (modern Turkey)
Population: ~5,000–10,000 people
Status: One of the earliest known proto-cities
Çatalhöyük had no streets — houses were entered through holes in the roof. The dead were buried under the floors of living spaces. Walls were plastered and repainted with elaborate hunting scenes and abstract designs. There is little evidence of hierarchy: no palace, no obvious elite district.
It challenges our assumption that cities require kings.
◆ ~5000–4000 BCE — The Copper Age (Chalcolithic)
Location: Near East, Europe, South Asia
Metalworking begins with copper — easier to work than bronze (which requires tin alloying). Copper tools supplement but don't yet replace stone. Metallurgy spreads along trade networks, connecting communities across hundreds of kilometers.
◆ ~3500–3100 BCE — The First Writing Systems
Location: Sumer (modern Iraq) and Egypt
The Sumerians develop cuneiform writing — wedge-shaped marks pressed into clay tablets — initially for accounting: records of grain, livestock, and trade goods. Within centuries, it evolves to record laws, literature, and religious texts.
The Egyptians develop hieroglyphics contemporaneously (possibly independently, possibly influenced by contact with Sumer). Writing transforms civilization: now knowledge can outlive individuals, laws can be standardized, and stories can travel without a human carrier.
The Epic of Gilgamesh (~2100 BCE in written form, but drawing on older traditions): The oldest surviving work of literature. A king seeks immortality and finds wisdom instead. Its themes — friendship, mortality, hubris, the search for meaning — are as fresh today as they were four thousand years ago.
◆ ~3100 BCE — Egypt Unified
Pharaoh: Narmer (or Menes)
Capital: Memphis (and the mysterious Thinis)
─────────────────────────────────────────
THE MISSING PERSONS: LOST CITIES AND VANISHED CIVILIZATIONS
─────────────────────────────────────────
History remembers the victors and the survivors. But some of the most fascinating chapters are the ones we've nearly lost — cities whose ruins we have never found, empires whose collapse remains mysterious, peoples whose very names we know only from enemies' records.
◆ THINIS — The First Capital of Egypt
Period: ~3100–2686 BCE (Early Dynastic period)
Location: Probably near modern Girga, Upper Egypt
Status: Location unconfirmed; possibly destroyed or buried
Thinis (also spelled Tjeni or This) is named in ancient king lists as the capital of the first pharaohs who unified Egypt — the dynasty of Narmer and Hor-Aha. According to ancient texts, the Early Dynastic pharaohs were buried nearby in the necropolis of Abydos. Yet Thinis itself has never been found.
What we know: Ancient Greek historians mention it. It was likely on the Nile's west bank, near the bend at Girga. Abydos is nearby, confirming the general region.
What we don't know: Its precise location. Its size. What it looked like. Why it was abandoned (it likely declined when Memphis, further north, became the dominant capital). Whether its ruins lie beneath modern sediment or were simply dismantled and reused.
Thinis is a ghost city — we know it existed, we cannot find it. The first capital of one of history's greatest civilizations has vanished.
◆ AGADE (AKKAD) — Capital of the World's First Empire
Period: ~2334–2154 BCE
Civilization: Akkadian Empire under Sargon the Great
Location: Somewhere in central Mesopotamia (modern Iraq)
Status: Completely unlocated
Sargon of Akkad built history's first true empire — a polity that ruled by military conquest and administrative control over disparate peoples. At its peak, the Akkadian Empire stretched from the Persian Gulf to the Mediterranean. Its capital, Agade, was described as magnificent: rich with temples, storehouses, quays loaded with trade goods from across the known world.
Then it fell. Around 2154 BCE, the empire collapsed — possibly due to a prolonged drought (the 4.2-kiloyear event), internal revolt, or pressure from the Gutians. Agade was sacked and apparently abandoned so thoroughly that subsequent generations couldn't find it either.
What we know: Agade was probably on the Tigris River, near modern Baghdad. It was large enough to be an imperial capital. After its fall, it became a byword for greatness lost — Babylonian texts mourned its destruction for centuries.
What we don't know: Almost everything. Its exact location. Its layout. The language of its people beyond what was written in cuneiform. Whether it lies beneath an unexcavated tell, beneath a modern city, or was deliberately obliterated. No ruin has ever been definitively identified as Agade.
A city so important it invented empire, so thoroughly lost that even its ruins are unknown.
◆ PUNT — Egypt's Mysterious "Land of the Gods"
Period: Referenced from ~2400 BCE to ~1100 BCE
Location: Somewhere on the Red Sea coast — East Africa or Arabian Peninsula
Status: Location hotly debated
The ancient Egyptians called Punt "Ta Netjer" — the Land of the God. They sent expedition after expedition there to bring back incense trees, ebony, gold, animal skins, live animals, and resins used in religious ceremonies. Queen Hatshepsut's famous expedition (~1490 BCE) is depicted in stunning relief on the walls of her mortuary temple at Deir el-Bahri — showing the foreign landscape, the queen of Punt, and the goods exchanged.
What we know: Punt had incense trees (probably myrrh and frankincense), cattle, and specific wildlife including baboons. Its coastal access suggests a Red Sea location. Isotopic analysis of baboon mummies from Egypt suggests an East African origin (possibly Eritrea/Ethiopia region or even Yemen/Somalia coast).
What we don't know: The definitive location. Whether Punt was a single kingdom or a trade network. Why Egyptian references to it cease after ~1100 BCE. Whether its people are ancestors of modern Somali, Eritrean, Yemeni, or other populations.
Egypt's most treasured trading partner, the source of sacred incense for a thousand years — and we cannot say with certainty where it was.
◆ TARTESSOS — The Silver Kingdom at the Edge of the World
Period: ~900–500 BCE
Location: Southern Iberian Peninsula (modern Andalusia, Spain)
Status: Core city unlocated; may be in the Guadalquivir River marshes
To the ancient Greeks, Tartessos was at the edge of the known world — beyond the Pillars of Hercules (Strait of Gibraltar), rich in silver and metals, governed by a legendary king named Arganthonios who lived to 120 years and was renowned for his generosity. The Tartessians traded silver and copper with the Phoenicians, Greeks, and Carthaginians.
Around 500 BCE, Tartessos simply disappears from the historical record. The city is never found. The Carthaginians' commercial monopoly in the western Mediterranean may have been a factor in its decline, or it may have been flooded by rising sea levels in the Guadalquivir delta.
What we know: Tartessian inscriptions exist — in a language not yet fully deciphered, written in a semi-alphabetic script. Gold and silver objects of Tartessian origin show sophisticated metallurgy. The culture influenced local Iberian development.
What we don't know: Where the capital city was. The political structure. The language (though inscriptions survive). Whether it was destroyed, abandoned, or simply absorbed.
A kingdom of silver at the edge of the ancient world — its coins survive, its inscriptions speak an unreadable language, its city is nowhere.
◆ CARAL-SUPE — The Oldest Civilization in the Americas
Period: ~3000–1800 BCE
Location: Supe Valley, coastal Peru
Status: Known and excavated, but poorly understood; no writing system found
Caral challenges everything. Here, in coastal Peru, a complex civilization arose at the same time as the Old Kingdom of Egypt — with monumental pyramid-like platforms, plazas, circular sunken courts, and a complex urban plan covering 626 hectares. And yet there is no pottery, no evidence of warfare in the earliest phases, and no writing.
Their recording system appears to have been the quipu — knotted strings that may encode complex information — but the quipu remains undeciphered. Caral's people ate fish and grew cotton for fishing nets; they appear to have been a maritime-agricultural economy that traded widely.
What we know: Six major pyramid complexes. Sophisticated urban planning. Evidence of music (flutes). A population estimated at 3,000–5,000 in the capital, perhaps 30,000 across the Norte Chico region.
What we don't know: Their language. Their religious beliefs in detail. Why the civilization collapsed around 1800 BCE. Whether the quipu tradition of the later Inca was descended from Caral's recording system.
The oldest city in the Americas — older than the Olmec, contemporary with ancient Egypt — and we cannot read a single word they wrote (if they wrote at all).
◆ CAHOKIA — The Largest City North of Mexico
Period: ~600–1400 CE (peak: ~1050–1200 CE)
Location: Near modern East St. Louis, Illinois, USA
Status: Ruins survive; people and culture still unclear
At its peak around 1100 CE, Cahokia had a population of 10,000–20,000 people — larger than London at the same time. Monks Mound, the central platform, is larger at its base than the Great Pyramid of Giza. A complex of 120 earthen mounds, wooden palisades, and arranged plazas dominated the Mississippi floodplain.
And then — within a few centuries — everyone left. By 1300–1400 CE, Cahokia was abandoned. No descendants have definitively claimed it. The people dispersed into surrounding cultures.
What we know: A sophisticated cosmological worldview expressed in the layout of mounds. Long-distance trade networks stretching to the Gulf Coast and Rocky Mountains. Evidence of human sacrifice (Mound 72). Agriculture centered on maize. A ruling elite.
What we don't know: The name of the city (Cahokia is a French colonial name of a different tribe). The language. The specific reasons for abandonment — climate change, social collapse, disease, drought, political fragmentation? The fate of the population.
The greatest city in pre-Columbian North America — and we don't know what its inhabitants called it, what language they spoke, or why they left.
◆ OTHER VANISHED WORLDS (Brief Entries)
The Indus Valley Civilization (~2600–1900 BCE)
Mohenjo-daro and Harappa: cities with advanced urban planning, sanitation systems, a script still undeciphered after 150 years of effort. They traded with Mesopotamia. Then the cities were abandoned. We cannot read their language.
The Minoan Civilization (~2700–1450 BCE)
Centered on Crete, with palace complexes like Knossos and a writing system (Linear A) still undeciphered. Possible connection to the mythical Atlantis in Plato's account (via the Thera volcanic eruption ~1600 BCE). Absorbed or destroyed by Mycenaean Greeks.
Nan Madol (~1200–1500 CE, Micronesia)
92 artificial islands built on a reef, connected by canals, constructed from basalt boulders up to 50 tons each — without metal tools. The builders' identity and the source of the megaliths remain puzzling.
Great Zimbabwe (~1100–1420 CE)
Stone-walled enclosures housing a gold-trading kingdom. The name Zimbabwe means "houses of stone." For colonial-era Europeans, the idea that Africans had built such structures was literally unthinkable — they invented absurd theories about Phoenicians or the Queen of Sheba. The builders were the Shona people.
─────────────────────────────────────────
THE GREAT MILESTONES IN CONDENSED FORM
─────────────────────────────────────────
| Date | Event | Significance |
|---|---|---|
| 7 Mya | Sahelanthropus tchadensis | Possible first hominin |
| 3.7 Mya | Laetoli footprints | Confirmed bipedalism |
| 2.6 Mya | Oldowan tools | First technology |
| 1.9 Mya | Homo erectus spreads | First intercontinental migration |
| ~1 Mya | Controlled fire | Cooking, warmth, social bonding |
| 300,000 BP | Homo sapiens emerges | Modern anatomy |
| 100,000 BP | Symbolic behavior | Language, art, identity |
| 65,000 BP | Out of Africa | Global colonization begins |
| 40,000 BP | Upper Paleolithic art | Full behavioral modernity |
| 11,000 BCE | Agriculture begins | Civilization engine |
| 9600 BCE | Göbekli Tepe | Monumental architecture before farming |
| 3500 BCE | Writing invented | Knowledge escapes mortality |
| 3100 BCE | Egypt unified | First nation-state |
| 2334 BCE | Sargon of Akkad | First empire |
| 776 BCE | First Olympic Games | Shared cultural identity |
| 551 BCE | Confucius born | Axis Age philosophy |
| 500 BCE | Athenian democracy | Political experiment |
| 44 BCE | Julius Caesar assassinated | Empire replaces republic |
| 570 CE | Muhammad born | Islam emerges |
| 1066 CE | Norman Conquest | Medieval Europe reshaped |
| 1347 CE | Black Death reaches Europe | 1/3 of Europe dies |
| 1440 CE | Gutenberg press | Information democratized |
| 1492 CE | Columbus reaches Americas | Old World meets New World |
| 1687 CE | Newton's Principia | Scientific revolution matures |
| 1776 CE | American Declaration | Democracy re-emerges at scale |
| 1859 CE | Darwin's Origin of Species | Humanity understands its past |
| 1945 CE | Atomic bomb | Species-level existential risk created |
| 1969 CE | Moon landing | Humans leave the planet |
| 2003 CE | Human genome sequenced | We read our own code |
| 2022 CE | AI systems reach human-level language | New form of intelligence emerges |
─────────────────────────────────────────
CODA: THE SHAPE OF DEEP TIME
─────────────────────────────────────────
If the entire history of Earth were compressed into a single calendar year, humans appear on December 31st — in the last few hours before midnight. Agriculture, writing, and all of recorded history occupy the final few seconds.
This perspective is not humbling in a diminishing sense. It is humbling in the way that standing at the ocean is humbling: you are small, yes, but you are part of something immeasurably vast and old. Every civilization discussed in this document — from the lost splendor of Agade to the mystery of Cahokia — was built by beings with the same cognitive hardware you are using to read these words.
They loved, feared, wondered, built, mourned, and eventually were forgotten. The Akkadians mourned Agade for a thousand years; the Egyptians sent ships to Punt for fifteen hundred; the descendants of Cahokia's builders are still here, in communities across the Midwest, carrying genes and stories that connect to those mounds.
The deep time perspective does something else: it reveals contingency. Homo sapiens nearly went extinct at least once. The agricultural revolution happened in at most a handful of places before spreading globally. Writing was invented independently perhaps three times. These are not inevitable developments — they are improbable survivals, lucky turns, narrow passages through which all subsequent history was threaded.
We are the survivors of multiple near-misses, the heirs of unknown millions, the temporary custodians of a four-billion-year biological legacy. The Observatory Almanac exists in part to help us remember this — to look at the world with the depth of time it deserves.
What we have lost, we can mourn. What survives, we must treasure.
Sources and further reading: Ian Tattersall — The Fossil Trail; David Reich — Who We Are and How We Got Here; Charles Mann — 1491; David Wengrow & David Graeber — The Dawn of Everything; Yuval Noah Harari — Sapiens; Andrew Robinson — The Story of Writing.