ENVIRONMENT

The Fall of the Giants

~50,000 to 10,000 years ago

Palaeolithic · Upper Palaeolithic · Last glacial

In the last act of the ice age, Earth lost around half of its large mammal species: giant kangaroos and marsupial lions in Australia, mammoths and woolly rhinos in Eurasia, ground sloths, mastodons and native horses in the Americas. The century-old question, climate or people, has been tested worldwide: extinction severity follows the map and timing of human expansion far better than any climate signal, hitting hardest where humans arrived as strangers.

Why it matters

This is the first planetary-scale transformation of the living world by our species, and it happened deep in the ice age. Losing the giants rewired whole ecosystems, from seed dispersal to fire regimes, and left most continents with a fauna that is, ecologically speaking, missing its upper floors, Africa least of all. The elephants and rhinos that survive today are the remnant of that world, and the debate over their ancestors' fate is also an argument about ours.

Dating & uncertainty

The losses were staggered, continent by continent, and that is precisely the evidence: severity tracks the geography of human arrival, and weighs heaviest where hominins came last. How much still falls to climate is unsettled, from at most a weak, Eurasia-specific link in one global analysis to a real but secondary role in another, which also admits it cannot account for the low extinction rate of mainland Asia. The anchor sits mid-interval: Australia's giants went early, the Americas' near the close of the glaciation, and islands like Wrangel held survivors for millennia more.

Sources

1. Sandom et al. (2014), Proceedings of the Royal Society B · Global late Quaternary megafauna extinctions linked to humans, not climate changedoi:10.1098/rspb.2013.3254
2. Bartlett et al. (2016), Ecography · Robustness despite uncertainty: regional climate data reveal the dominant role of humans in explaining global extinctions of late Quaternary megafaunadoi:10.1111/ecog.01566
3. Lemoine et al. (2023), Anthropocene · Megafauna extinctions in the late Quaternary are linked to human range expansion, not climate changedoi:10.1016/j.ancene.2023.100403

Our species’ history as one day

21:42:512 h 17 min before midnight

if the 315,000 years of Homo sapiens were compressed into a single day