250 thousand years ago: origin of Homo sapiens.
The origin of Homo sapiens is dated 250 to 300 thousand years ago, which does not mean that humans appeared abruptly. All it means is that those individuals alive 250 thousand years ago, descendants of ancient ancestors, were already “modern humans.” Any of them all dressed up in suit and tie would go unnoticed walking down a street in Paris.
There are no fossils dated 250 thousand years ago, so the origin of humankind is estimated based on all the tools found and the trend in the size of the skull in all other hominids.
In 1871, Darwin said Africa would turn out to be the cradle of humanity, since our closest relatives, the great apes─gorillas and chimpanzees─live there. Until 1925, nobody believed Darwin. Most scientists thought humans had appeared in Asia since the first fossils of Homo erectus─Java Man in 1891 and Peking Man in 1929─had been found there. It was not until the second half of the 20th century when a vast number of fossils of different species of hominids were found in East Africa, that Darwin’s original idea was accepted.
Today there is no doubt Homo sapiens evolved in Africa and is the only surviving species of all the hominids that lived in the Rift Valley for the last 7 million years.