Grass conquers the world
A plant that survives being eaten — and reshapes every animal
See it on the timeline →In depth
Grasses arose in the Cretaceous, but grassland as an ecosystem spreads only in the Miocene, strongly accelerated by C4 photosynthesis, which is efficient at low CO₂ and high temperature. The coevolution with grazers is among the best documented in the fossil record: horse teeth become high-crowned as silica from the grass wears them down, and leg length increases. Grass is also the basis of modern nutrition — wheat, rice, maize, barley, millet and sugar cane are all grasses. Without Miocene grasslands, neither the savanna humans evolved on nor the agriculture they later invented would exist.
For children
Grass grows from the base, not the tip. That is why it survives being grazed down again and again. As grasslands spread, animals followed: horses, antelope and wildebeest with tall teeth that resist wear, and long legs for outrunning predators in the open.
Connects to
Part of Terra Saga — the story of Earth on a timeline. terrasaga.org