Humans left Africa long before Homo sapiens even existed
Until the early 1980s, researchers assumed early humans stayed in Africa until roughly 800,000 years ago. Now possible stone tools in central China are dated to 2.12 million years, and skulls from Dmanisi in Georgia to 1.8 million. Several waves of archaic humans spread across Eurasia, collectively nicknamed Out of Africa I.
These dispersals ran from about 2.1 million to 0.2 million years ago, well before modern humans made their own exit, sometimes called Out of Africa II. Our genus probably arose roughly 2.8 million years ago, and Kenya's Lake Turkana has yielded Homo habilis, and Homo erectus arose just after 2 million years ago, sharing East African landscapes with habilis for close to 500,000 years. Even older tools, retouched stones from Lomekwi in Kenya dated to 3.3 million years, predate Homo altogether.
Dmanisi has yielded the oldest human bones outside Africa, classified as Homo erectus georgicus. One skull belonged to an elderly individual who had lost almost all teeth long before death. David Lordkipanidze and colleagues argued this person probably survived only with help from others, perhaps including softened food, making it possible early evidence of caring for the old or infirm.
Once in the Caucasus, erectus spread fast: fossils appear at Yuanmou in China by 1.7 million years ago and at Sangiran on Java by 1.66 million. Ferring and colleagues proposed that the first arrivals in West Asia were Homo habilis, with erectus evolving there before fanning out to East Asia, Java, Europe and even back into Africa. Europe was settled later; the earliest firm site, Barranco León in Spain, dates to 1.4 million years and is linked to Homo antecessor. Early humans there seem to have been sensitive to cold, failing to spread north of the Alpide mountain belt. Further waves around 0.8 million years ago brought cleaver-making groups linked to Homo heidelbergensis.
The tiny Homo floresiensis of Indonesia complicates things. Its anatomy most resembles Australopithecus sediba, Homo habilis and the Dmanisi people, and a 2017 analysis placed its lineage before erectus, implying an unknown migration earlier than 2.1 million years ago.
Source: Early expansions of hominins out of Africa
