Early human migrations are the earliest migrations and expansions of archaic and modern humans across continents. They are believed to have begun approximately 2 million years ago with the early expansions out of Africa by Homo erectus. This initial migration was followed by other archaic humans including H. heidelbergensis, which lived around 500,000 years ago and was the likely ancestor of Denisovans and Neanderthals as well as modern humans. Early hominids had likely crossed land bridges that have now sunk. Within Africa, Homo sapiens dispersed around the time of its speciation, roughly 300,000 years ago. The recent African origin paradigm suggests that the anatomically modern humans outside of Africa descend from a population of Homo sapiens migrating from East Africa roughly 70–50,000 years ago and spreading along the southern coast of Asia and to Oceania by about 50,000 years ago. Modern humans spread across Europe about 40,000 years ago. Early Eurasian Homo sapiens fossils have been found in Israel and Greece, dated to 194,000–177,000 and 210,000 years old respectively. These fossils seem to represent failed dispersal attempts by early Homo sapiens, who were likely replaced by local Neanderthal populations. The migrating modern human populations are known to have interbred with earlier local populations, so that contemporary human populations are descended in small part (below 10% contribution) from regional varieties of archaic humans. After the Last Glacial Maximum, North Eurasian populations migrated to the Americas about 20,000 years ago. Northern Eurasia was peopled after 12,000 years ago, at the beginning of the Holocene period. Arctic Canada and Greenland were reached by the Paleo-Eskimo expansion around 4,000 years ago. Finally, Polynesia was populated within the past 2,000 years in the last wave of the Austronesian expansion. Early humans (before Homo sapiens) The earliest humans developed out of australopithecine ancestors about 3 million years ago, most likely in Eastern Africa, most likely in the area of the Kenyan Rift Valley, where the oldest known stone tools were found. Stone tools recently discovered at the Shangchen site in China and dated to 2.12 million years ago are claimed to be the earliest known evidence of hominins outside Africa, surpassing Dmanisi in Georgia by 300,000 years. Homo erectus Between 2 and less than a million years ago, Homo spread throughout East Africa and to Southern Africa (Homo ergaster), but not yet to West Africa. Around 1.8 million years ago, Homo erectus migrated out of Africa