Repeated glacial and interglacial cycles caused large sea-level swings. Homo sapiens emerged and spread across the globe, reaching the present day.
Explore the Quaternary Earth in 3D →Pleistocene glacial-interglacial cycles began. Massive ice sheets periodically covered the Northern Hemisphere, with sea level swings of 120m+. Profoundly shaped human migration and evolution.
Homo erectus began controlling fire. Cooking, warmth, and predator defense enabled dramatic brain development and social structure advancement.
Modern humans, Homo sapiens, appeared in Africa. From ~70,000 years ago they spread across the globe, becoming Earth's dominant species.
About 74,000 years ago, the Toba volcano in Sumatra erupted in the largest eruption of the past 2 million years, triggering a volcanic winter lasting years. The 'bottleneck hypothesis' — that it reduced human population to thousands — is being reassessed in light of archaeological continuity found in Africa and India. The actual human impact remains debated.