Two timelines, one question

Where we all
came from

Everything below is anchored to a published source — journal, volume, year, DOI — with the dating method named and the level of disagreement stated. Where specialists are still fighting about a date, you will see the fight rather than a tidy number.

—dated finds
—citations
4.5 Gacovered
scroll

Start here

The two clocks are not the same clock

The brief asked for continental drift and human migration on one timeline. They belong on one page, but you should see immediately why they cannot share an axis. Each bar below is drawn to true scale against the age of the Earth.

Pangaea finished breaking apart 175 million years ago. The genus Homo appears 2.8 million years ago. Our species appears 315,000 years ago. By the time there is anyone to migrate, the continents are already sitting almost exactly where they sit now.

Continental drift did not move humans around. Sea level did. Every land bridge that matters — Beringia, Sundaland, Sahul, Doggerland — is a continental shelf that drained when ice sheets locked up the water, and flooded again when they melted. The plates were bystanders.

Act I

What the continents actually did

From molten rock to the map on the wall. The land moves; watch the ocean gateways, because those are what change the climate that everything else depends on.

Act I · The Earth
horizontal →

Act II

The human record

Every card is a specific find, in a specific place, dated by a named method, reported in a named paper. Colour marks how much argument surrounds it. The teal band at the end is the dispersal that everyone alive outside Africa descends from — note how many earlier attempts precede it, and how few of them left any descendants.

Act II · The human record
2 million years ago

Checked against the record

The claims in the brief

Four things were asserted going in. Here is what the literature says about each — including the one that is essentially right, and the one that is out by a factor of thirty thousand.

Everything, listed

Sources

Deduplicated from every card above. Links resolve to DOIs where one exists. Nothing on this page is stated without one of these behind it.

    How to read the dates

    Radiocarbon (¹⁴C)
    Organic material only, and useless past about 50,000 years. Almost every date older than that on this page comes from something else.
    Luminescence (OSL, TL, pIR-IRSL)
    Measures how long since a mineral grain last saw sunlight or fire. Dates the sediment around a find, not the find. This is the workhorse for the 10,000–500,000 year range.
    Uranium-series & ESR
    Uses uranium decay taken up by teeth, bone and cave carbonate. Powerful, but sensitive to assumptions about how uranium moved through the sample — which is why several disputes on this page are U-series disputes.
    ⁴⁰Ar/³⁹Ar
    Dates volcanic layers. Where a fossil sits between two ash falls, this brackets it precisely. It is why the Ethiopian rift record is the best-dated in the world.
    Molecular dating
    Reads mutation accumulation and the length of inherited DNA blocks. Dates events, not objects — which is why it can bracket "when we left Africa" without any fossil at all.

    Built as a research artefact. Where a published rebuttal exists, it is cited next to the claim it attacks rather than omitted. Compiled July 2026 — palaeoanthropology moves, and several dates here have already changed once.