Before discussing the dating of African fossil sites, it is necessary to explain the division and name of the Stone Age in Africa, which is different from other regions. The Stone Age in Africa is divided into early stone age, middle stone age and late stone age. 1970, Clark proposed that the Middle Stone Age (MSA) in Africa was about 40,000 ~ 65,438+million years ago, which was roughly equivalent to the middle Paleolithic period in Europe. However, in 1972, vogel and Beaumont published a series of survey data of various fossil sites in Africa 14C, which greatly revised the age of the Stone Age in Africa, and considered that the Mesolithic Age began 65,438+million years ago and ended 37,000 years ago.
According to the determination of oxygen isotopes, the deposition of caves in the border of South Africa shows that the Stone Age first began about 6,543,800 years ago. At another location, the measurement of the clarice estuary began about 654.38 million+250,000 years ago. The Stone Age in East Africa was also advanced. The Stone Age near Qiwei Lake in Ethiopia was determined by potassium argon method, which was about 18 100006 years ago and149000 0.13000 years ago respectively. The Stone Age of Ngaloba horizon in Letori, Kenya is about 1.20 million 0.30 million years ago.
Knowledge point oxygen isotope
In nature, oxygen exists in three isotopes: 16O, 17O and 18O, with relative abundances of 99.756%, 0.039% and 0.205% respectively. The oxygen isotope composition of natural substances is usually δ, which is determined by the ratio of 18O/ 16O.
Oxygen isotope is widely used in earth science to determine the source of diagenetic substances and the diagenetic and metallogenic temperature. It has broad application prospects in biology and medicine. According to various data, the transition period from the latest Achery period to the earliest Stone Age in Africa was between 6,543,800+3,000 years and 200,000 years ago. The study of boundary caves shows that the latest age is about 50 thousand years ago.
The main fossil sites related to the origin of black people found in Africa are Floresba in South Africa, border caves and the mouth of Clarice River, Omo in Ethiopia in East Africa and Ngaroba in Tanzania.
Florespa fossil was found in South Africa in 1932, and its materials include complete frontal bone, partial parietal bone and right facial bone. Its age may be 40 thousand years ago. It may be related to the group formerly called Bushmen, and now it is renamed San, but some people think that it has nothing to do with San, but has similar characteristics to the Brocken Mountain specimen.
Border caves are located in the north of natal province. From 194 1 up to now, fossils representing at least four individuals have been found there. There is evidence of long-term human habitation in the cave, but the stratigraphic records are chaotic. The latest age is 6.5438+0.5 million years ago, and the earliest age is 48,000 years ago. The soil attached to some skulls is over 6.5438+0 million years old. All the forms of human fossils obviously belong to modern people. Devi Liers of 1973 and Beaumont of 1978 emphasize that boundary cave fossils are the ancestors of modern African blacks, but other anthropologists such as Reitemeier of 1984 think it is impossible. Multivariate analysis of skull measurement shows that individuals belonging to boundary cave fossils are similar to existing male mulberry people.
Fossils from the mouth of the clarice River were found in this cave on the coast of the Cape of Good Hope. The human fossils in the cave include skull fragments and a relatively complete mandible. Its shape is completely similar to that of modern Homo sapiens. Stone tools and many animal fossils from the Middle Stone Age were found in the same place. Its earliest age ranged from 6.5438+0.2 million years ago to 6.5438+0.3 million years ago, and the latest was about 60,000 years ago. Such people have lived here for at least 60 thousand years.
Omo specimens are two skulls discovered in Kibishi Formation in Omo Basin in southern Ethiopia in 1967. Omo-2 has a large brain shell, and its brain capacity exceeds 1 400 ml. Its age cannot be determined. The age of mussel shells unearthed in the accumulation was determined by uranium thorium method, which was 654.38 0.3 million years ago. The shape of the skull is similar to that of earlier modern Homo sapiens.
1976 A well-preserved skull was found in Ngalobadipin, Letori, Tanzania, which is obviously in the form of modern Homo sapiens, but some primitive features, such as the developed eyebrow ridge, are similar to Omo's skull. From stratigraphic correlation, it can be concluded that its age is equivalent to the horizon of 6.5438+200,000 years ago.
The human fossils in Magris, south of the Mediterranean Sea and along the Moroccan Atlantic coast, are less than 50,000 years ago, which shows that Neanderthals and modern Homo sapiens are similar to Neanderthals in West Asia, so they are considered to be interrelated and have gene exchange.
Generally speaking, the above-mentioned human fossils in Africa are close to modern people; The reliability of its age is different and there are some problems. The existing evidence cannot confirm that modern Homo sapiens differentiated earlier in sub-Saharan Africa. However, the results of chronological revision show that the view that sub-Saharan Africa is backward and stagnant in technology compared with North Africa and Europe in the past is obviously incorrect. Important technological changes in sub-Saharan Africa may occur at about the same time or even earlier, although they belong to different systems in cultural nature.