Coexistence circa 1.8M: Paranthropus boisei, Homo rudolfensis, H. habilis and H. ergaster foraged in the same area around Lake Turkana.
In Africa, H. erectus may have evolved into H. heidelbergensis, but in Asia a dead end.
Morphological traits typical of Neanderthals began to appear in European hominids at least 400,000 years ago and about 150,000 years ago in western Asia.
Neanderthal sites: at least 30 (Neander Valley, Germany, 1856; Sipka, Moravia 1880; Spy, Belgium 1886; Krapina, Croatia, 1899-1906; Ehringsdorf, Germany 1908-1925; Le Moustier, France 1908; St. Brelade, Channel Islands, 1911; Kiik-Koba, Crimea, 1924; Mount Carmel, Palestine, 1929; Teskhik-Tash, central Asia, 1938; Saccopastore, Italy, 1929; Guattari/Circeo, Italy, 1939; Shanidar, Iraq, 1953; Amud, Israel, 1961; Kebara, Israel, 1964; Dederiych, Syria, 1993; St. Cesaire, France 1979; Zaffaraya, Spain, 1983; Lakonia, Greece, 1999)
All modern human genes originated in Africa; in past 2 MYA, Africa was source of emigration of a H. ergaster hominin, then a H. heidelbergensis hominin, then several waves of modern humans; modern humans are derived from relatively recent, ca. 50-45 kya migration out of East Africa.
Homo sapiens sites: Pestera cu Oase, Romania, c. 35 kya; Kent’s Cavern, England, c 30 kya; Bacho Kiro & Temnata, Bulgaria 43-40 kya; Papua New Guinea, Australia, Tasmania, 40 kya; Oceania, 35-30 kya; Arctic Circle, 27 kya; preClovis culture, Texas, 15 kya, Monte Verde, Chile, 12.5 kya; Clovis culture, before 11 kya
Homo sapiens: migration out of Africa, then interbreeding with Neanderthals in Western Asia (65,000–90,000 years ago); (contributed 1-4% of their DNA to Homo sapiens); then a move to Southeast Asia; ancestors of East Asians and Western Indonesia arrived later, between 38-25TYA
2 migrations into Asia from Africa
1 - Denisovans: a common ancestor with anatomically modern human and Neanderthal mtDNAs about 1.0 million years ago. This indicates that it derives from a hominin migration out of Africa distinct from that of the ancestors of Neanderthals and of modern humans; 4-6% DNA to New Guinea, Melanesia, Aborigines by 44 TYA; human migration to SE Asia between 75 and 62TYA
2 – No Denisovan DNA: To East Mainland Asia (Han Chinese) and Western Indonesia
Bernard Wood – Human Evolution, 2011
Richard Klein – Richard G. Klein, 2009
Modern Human vs. Chimpanzee Skeleton (after B. Wood):
Hip joint: outer/cortical bone is thickest at top and bottom of neck
The Toba catastrophe theory suggests that a bottleneck of the human population occurred c. 70,000 years ago, proposing that the human population was reduced to perhaps 15,000 individuals when the Toba supervolcano in Indonesia erupted and triggered a major environmental change. The theory is based on geological evidences of sudden climate change and on coalescence evidences of some genes (including mitochondrial DNA, Y-chromosome and some nuclear genes) and the relatively low level of genetic variation with humans.
However, such coalescence is genetically expected and does not, in itself, indicate a population bottleneck, because mitochondrial DNA and Y-chromosome DNA are only a small part of the entire genome, and are atypical in that they are inherited exclusively through the mother or through the father, respectively. Most genes in the genome are inherited from either father or mother, and thus can be traced back in time via either matrilineal or patrilineal ancestry. Research on many genes finds different coalescence points from 2 million years ago to 60,000 years ago when different genes are considered, thus disproving the existence of more recent extreme bottlenecks (i.e., a single breeding pair).
On the other hand, in 2000, a Molecular Biology and Evolution paper suggested a transplanting model or a 'long bottleneck' to account for the limited genetic variation, rather than a catastrophic environmental change. This would be consistent with suggestions that in sub-Saharan Africa numbers could have dropped at times as low as 2,000, for perhaps as long as 100,000 years, before numbers began to expand again in the Late Stone Age.