Two chapters, the same questions asked of both
Put two Deep Time chapters next to each other — their evidence base, the dating methods behind them, the live debates, and the questions still open.
Homo Erectus
The first long-distance migrants — fire, hand axes, and a two-million-year run.
Open full chapter →Neanderthals
Burial, pigment, and the genomic evidence for interbreeding with modern humans.
Open full chapter →A comparatively rich fossil sample across Africa and Asia, Acheulean handaxe assemblages, and site-level evidence of fire.
Skeletons, Mousterian tool assemblages, burials, pigment and shell use, and sequenced ancient genomes.
| Method | What it constrains |
|---|---|
| Palaeomagnetic and radiometric site datingSediments and volcanic layers at Eurasian and African sites | Establishes presence at a place and time; it does not trace a migration route. |
| Postcranial morphologyLimb bones and reconstructed skeletons | Indicates stature and locomotor efficiency. Behaviour is inferred. |
| Microstratigraphy of combustion featuresAsh, burnt bone and heated sediment in hearth-like deposits | Can show fire in a place. Distinguishing controlled fire from natural burn requires context. |
| Method | What it constrains |
|---|---|
| Ancient DNA sequencingBone and tooth powder, and sediment DNA from cave floors | Establishes population relationships and admixture. Contamination control is the whole ballgame. |
| Radiocarbon with ultrafiltrationCollagen from bone near the limit of the method | Improved pretreatment pushed many 'late' dates older, revising overlap estimates with modern humans. |
| Uranium–thorium dating of carbonate crustsFlowstone over cave art and structures | Gives a minimum age for what lies beneath the crust, not the act itself. |
When did habitual control of fire begin?
Claims range across hundreds of thousands of years depending on how strictly evidence is defined.
One widespread species or several regional ones?
Asian and African samples differ enough that some researchers split them.
How much symbolic behaviour is securely Neanderthal?
Several claimed cases turn on whether the dated crust really postdates the mark.
Why did they disappear as a distinct population?
Competition, climate, demography and absorption by admixture are all on the table.
- What drove the first sustained dispersals out of Africa?
- Why did the Acheulean remain stable for so long?
- How is the Asian material best classified?
- How large were their populations, and how fragmented?
- How much of the assimilation happened where and when?
- What did their language capacity actually look like?