ENVIRONMENT

The Fall of the Giants

~50,000 to 10,000 years ago

Palaeolithic · Upper Palaeolithic · Last glacial

Over the last ice age's final act, 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 debate over the cause, climate or people, has been tested globally: extinction severity follows the map and timing of human expansion far better than any climate signal, hitting hardest exactly where humans arrived as strangers.

Why it matters

This is the first planetary-scale transformation of the living world by our species, ten thousand years before farming. Losing the giants rewired whole ecosystems, from seed dispersal to fire regimes, and left every continent but Africa with a fauna that is, ecologically speaking, missing its upper floors. 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, which is exactly the evidence: extinction severity tracks the geography of human arrival, striking hardest where hominins came last, with at most a weak, Eurasia-specific link to climate. The anchor sits mid-interval; Australia's giants went early, the Americas' around the ice age's end, 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