Pre-industrial humans drove megafaunal extinctions wherever they newly arrived.

Evidence

Not only did ancient hunter-gatherers expand into most of the earth’s terrestrial ecosystems, we probably also contributed to the extinction of much of its megafauna—that is, to the extinction of large vertebrates like mammoths, mastodons, giant deer, woolly rhinos, immense ground sloths, and giant armadillos, as well as some species of elephants, hippos, and lions. While climatic shifts were also likely contributors to these extinctions, the disappearance of many megafaunal species eerily coincides with the arrival of humans on different continents and large islands. For example, before we showed up in Australia around 60,000 years ago, the continent was home to a menagerie of large animals, including two-ton wombats, immense meat-eating lizards (see figure 2.1 ), and leopard-sized marsupial lions. These, along with 55 other megafaunal species, went extinct in the wake of our arrival, resulting in the loss of 88% of Australia’s big vertebrates. Tens of thousands of years later, when humans finally arrived in the Americas, 83 genera of megafauna went extinct, including horses, camels, mammoths, giant sloths, lions, and dire wolves, representing a loss of over 75% of the existing megafauna. Similar patterns emerged when humans arrived at different times in Madagascar, New Zealand, and the Caribbean. — Joseph Henrich, The Secret of Our Success, 64

Categorization

• XREF: Connects to the reader’s earlier extract on human effects on megafauna and to the Osage-orange thorns vs. extinct megafauna point from the trees article. — connects to: Humans began migrating from Africa to other continents about 40,000 years ago. — Neil MacGregor, A History of the World in 100 Objects, 122; Human arrival caused most global megafaunal extinctions. — Joseph Henrich, The Secret of Our Success: How Culture…, 65
• ADDENDUM: Supports the tamarisk/megafauna theme in ‘Grafting & Growth: On Trees as Infrastructure’ by establishing that pre-modern humans already shaped ecosystems at scale.

Broader Connections

• Humans began migrating from Africa to other continents about 40,000 years ago. #responds-to (0.75) — Neil MacGregor, A History of the World in 100 Objects, 122