Evolution of Earth timeline. Computer illustration of a timeline showing the evolution of Earth,from its creation (far left) to the emergence of modern humans (far right),and how the emergence of more complex lifeforms coincided with a sharp increase in the Earth's atmospheric oxygen level (blue). From left to right: the Big Bang,formation of the Moon,formation of the oceans,emergence of sulphate-reducing bacteria,emergence of oxygen producing bacteria,first eukaryotes,emergence of exoskeleton animals,dinosaurs and humans |