13 chapitres Terminé About 1.5 billion years ago, the single-celled eukaryotes became the common ancestors of all multicellular plants, animals, and fungi.
Fish evolved a primitive lung sac and four limbs, 350 million years ago, so they could crawl between fresh water swamps.
About 250 million years ago, the ancestors of all mammals, were tiny nocturnal insectivores and, about 6 million years ago, we began walking on two legs.
The most recent Ice Age (2.6 million to 12,000 years ago), severely reduced rainfall in Africa, where Homo habilis was evolving.
In Homo erectus (1.9 to 0.5 million years ago), cranial capacity increased to between 850 and 1000 cm3 implying the phenomenal increase of 125,000 more neurons with each generation.
Between 70 and 50 thousand years ago, Homo sapiens spread out from east Africa.
Then, about 20,000 years ago, evolution made a sharp change in direction. After 250 million years, we ceased to be hunter gatherers. The Neolithic Revolution meant we could never go back.
WHO THE HELL ARE WE? is a series of short books and videos describing the evolution of civilization.
Almost everyone on the planet is five times wealthier than their ancestors only 50 years ago. This astonishing phenomenon has also improved health, education, and longevity. The cause; an explosive growth in ideas and productivity.
It began when we learned to control fire, evolved articulate speech and stumbled onto the way to create infinite wealth; free trade. The discovery of agriculture made us richer but we also learned how to destroy wealth. Great civilization grew up but then disappeared leaving only incredible ruins and ideas.
Later books detail some of the ideas and developments that increased the average life span from about 40 years to more than 80 and the average world income from less than $3 to more than $33 per person per day (and to $140 per day in some countries).
