250 likes | 325 Views
Homo sapiens sapiens. A short history of the ideas concerning modern human orgins.
E N D
A short history of the ideas concerning modern human orgins • 1943 Franz Weidenreich proposes that the present-day “racial” variation was traceable back to population of Homo erectus that settled the world 1 million years ago. This became the multiregional continuity model. • In 1987 this model is challenged by the outcome of a comparative study of mitochodrial DNA carried out by Alan Wilson, Rebecca Cann, and Mark Stoneking of UC Berkeley.
mitochondrial DNA (mtDNA) can only be inherited maternally. • Like nuclear DNA over time neutral mutations will appear, and the rate of the acquisition of these mutations by a population is assumed to be somewhat constant. This is the basis of the molecular clock. • As populations diverge and become isolated, they will acquire mutations that are unique to them. The more modern populations differ genetically, the more time is assumed to elapsed since they diverged. The population with the most variable DNA will be the oldest.
This work determined the African mtDNA to be the most variable. They posited the origins of H. sapiens sapiens in Africa. The presumed ancestor was estimated to have lived between 285,000 and 142,000 years ago. This became the basis for the Out of Africa model, aka Recent African Origins.
A massive comparative study of nuclear DNA, published in 1994, supported this conclusion.
Homo sapiens idaltu The remains of a number of individuals were found eroding out a the Awash river near the village of Herto remains were found in the Afar triangle in 2003 by a team that included Timothy White. One adult cranium has an endocranial volume of 1450 ml. The crania show cut marks and polish.
Bulging supraorbital torus Orthograde face Large teeth
Klassies River Mouth, South Africa • Excavated in the 1960’s. • Remains at the caves reflect a lifestyle of gathering shellfish, and hunting seal and antelope (but no fishing).
Date is estimated at 100,000 years BP based on oxygen istopes.
H. Sapiens and H. sapiens sapiens in the Levant A number of caves in the hills surrounding Haifa were excavated in the 1920’s and 1930’s. Mugharet es-Skhul (Cave of the Kids) and Mugharet et-Tabun (Cave of the Oven) were excavated in 1929-34 by Dorothy Garrod of Cambridge University. The skeletal material was analyzed and published by Theodore McCowen in 1939.
Skhul V, individual was buried clutching the jaw of a wild boar.
Kebara Cave (Mugharet al-Kebara) was initially tested in 1927 by Moshe Stekelis. • 1930-31 Dorothy Garrod and Francis Turville-Petre conducted an extensive excavation. • Stekelis returned in 1951, 1965, and 1966 to excavate again. • A third excavation was carried out by Ofer Bar-Yosef in the early 1980’s.
Skeleton of a male archaic Homo sapiens found by Ofer Bar-Yosef.
The levallois points are assumed to have been hafted onto spears
Initially all of the remains found at Tabun and Skhul were assumed to have been from one highly variable population, and to have dated to 40,000-50,000 years BP. Excavations at Tabun were carried out over 1967-1972 by Arthur Jelinek. He refined the stratigraphy, and examinations of New dates from the Mt. Carmel caves have been generated by thermoluminesence and electron spin resonance.