Prehistory
Paleocene-Eocene Thermal Maximum: Earth's Ancient Global Warming
A rapid release of thousands of billions of tonnes of carbon warmed the planet, acidified the oceans and reshaped marine and land life.
Region
Worldwide
Prehistory
Megalodon: The Giant Prehistoric Shark and Its Extinction
The largest known predatory shark dominated the world's oceans for some 20 million years before going extinct around 3.6 million years ago.
Prehistory
Acheulean Hand Axes: The Longest-Used Tool in Human History
The Acheulean hand axe became the most long-lived tool design in human history, made by several human species over more than 1.5 million years before giving way to Middle Stone Age and Middle Palaeolithic technologies.
Prehistory
Control of Fire by Early Humans: From Wonderwerk to the Hearth
Hominins used fire at least occasionally by about 1 million years ago, and regular use of hearths became widespread after about 400,000 years ago.
Prehistory
Toba Supereruption: The Volcano and the Human Bottleneck Debate
A colossal eruption spread ash from the South China Sea to Africa, but most current evidence suggests it did not cause a near-extinction of humans.
Prehistory
Out of Africa: How Homo sapiens Spread Across the World
All living people outside Africa descend mainly from a population that left Africa in this period and mixed along the way with Neanderthals and Denisovans.
Prehistory
Quaternary Megafauna Extinction: Why the Ice Age Giants Vanished
Roughly two-thirds of the world's genera of large land mammals disappeared, transforming ecosystems on every inhabited continent.
Ancient World
Sumerian Base-60 Numbers: Origins of Our 60-Minute Hour
Mesopotamian scribes created the first known place-value number system, in base 60, whose legacy survives in hours, minutes, seconds and the 360-degree circle.
Ancient World
Invention of Paper in China: Cai Lun and the Han Papermakers
Cai Lun's improved papermaking process made paper a practical writing material in China, from where the craft spread across Asia, the Islamic world and Europe.
Early Modern
Columbian Exchange: Crops, Animals and Diseases after 1492
Plants, animals, microbes and people were redistributed across the globe, transforming diets, economies and populations on every inhabited continent.
Early Modern
Treaty of Tordesillas (1494): Spain and Portugal Divide the World
Castile and Portugal agreed a dividing meridian 370 leagues west of the Cape Verde Islands, giving Portugal Africa, the route to Asia and later Brazil, and Castile most of the Americas.
Early Modern
Cantino Planisphere (1502): A Smuggled Portuguese World Map
The earliest surviving Portuguese world chart to record the discoveries in both the Americas and the Indian Ocean.