Migration Of Modern Humans
Ayinde:
Source: Stanford University
Date: 2003-05-28
Scientists Use DNA Fragments To Trace The Migration Of Modern Humans
Human beings may have made their first journey out of Africa as recently as 70,000 years ago, according to a new study by geneticists from Stanford University and the Russian Academy of Sciences. Writing in the American Journal of Human Genetics, the researchers estimate that the entire population of ancestral humans at the time of the African expansion consisted of only about 2,000 individuals.
"This estimate does not preclude the presence of other populations of Homo sapiens sapiens [modern humans] in Africa, although it suggests that they were probably isolated from one another genetically, and that contemporary worldwide populations descend from one or very few of those populations," said Marcus W. Feldman, the Burnet C. and Mildred Finley Wohlford Professor at Stanford and co-author of the study.
The small size of our ancestral population may explain why there is so little genetic variability in human DNA compared with that of chimpanzees and other closely related species, Feldman added.
The study, published in the May edition of the journal, is based on research conducted in Feldman`s Stanford laboratory in collaboration with co-authors Lev A. Zhivotovsky of the Russian Academy and former Stanford graduate student Noah A. Rosenberg, now at the University of Southern California.
"Our results are consistent with the `out-of-Africa` theory, according to which a sub-Saharan African ancestral population gave rise to all populations of anatomically modern humans through a chain of migrations to the Middle East, Europe, Asia, Oceania and America," Feldman noted.
Ancient roots
Since all human beings have virtually identical DNA, geneticists have to look for slight chemical variations that distinguish one population from another. One technique involves the use of "microsatellites" - short repetitive fragments of DNA whose patterns of variation differ among populations. Because microsatellites are passed from generation to generation and have a high mutation rate, they are a useful tool for estimating when two populations diverged.
In their study, the research team compared 377 microsatellite markers in DNA collected from 1,056 individuals representing 52 geographic sites in Africa, Eurasia (the Middle East, Europe, Central and South Asia), East Asia, Oceania and the Americas.
Statistical analysis of the microsatellite data revealed a close genetic relationship between two hunter-gatherer populations in sub-Saharan Africa - the Mbuti pygmies of the Congo Basin and the Khoisan (or "bushmen") of Botswana and Namibia. These two populations "may represent the oldest branch of modern humans studied here," the authors concluded.
The data revealed a genetic split between the ancestors of these hunter-gatherer populations and the ancestors of contemporary African farming people - Bantu speakers who inhabit many countries in southern Africa. "This division occurred between 70,000 and 140,000 years ago and was followed by the expansion out of Africa into Eurasia, Oceania, East Asia and the Americas - in that order," Feldman said.
This result is consistent with an earlier study in which Feldman and others analyzed the Y chromosomes of more than 1,000 men from 21 different populations. In that study, the researchers concluded that the first human migration from Africa may have occurred roughly 66,000 years ago.
Population bottlenecks
The research team also found that indigenous hunter-gatherer populations in Africa, the Americas and Oceania have experienced very little growth over time. "Hunting and gathering could not support a significant increase in population size," Feldman explained. "These populations probably underwent severe bottlenecks during which their numbers crashed - possibly because of limited resources, diseases and, in some cases, the effects of long-distance migrations."
Unlike hunter-gatherers, the ancestors of sub-Saharan African farming populations appear to have experienced a population expansion that started around 35,000 years ago: "This increase in population sizes might have been preceded by technological innovations that led to an increase in survival and then an increase in the overall birth rate," the authors wrote. The peoples of Eurasia and East Asia also show evidence of population expansion starting about 25,000 years ago, they added.
"The exciting thing about these data is that they are amenable to a combination of mathematical models and statistical analyses that can help solve problems that are important in paleontology, archaeology and anthropology," Feldman concluded.
###
The research was supported by grants from the National Institutes of Health, the National Science Foundation and the Russian Foundation for Basic Research.
Relevant Web URLs:
http://www-evo.stanford.edu/
http://news-service.stanford.edu/news/2003/january8/genetics-18.html
http://news-service.stanford.edu/news/november8/chromosome-1108.html
http://www.neanderthal-modern.com/genetic1.htm
Ras Mandingo:
Greetings Ayinde,
One question.
I remember you explaining how the melanin has the funtion of protecting the body from the sunlight, absorbing also essential nutrients from the sunlight.
White people got their amount of melanin reduced to adapt to the lack of sunlight, to make them able to use all the light they could get.
Am I right in this interpretation?
Well, so my question is, do black people suffer from the lack of light by living in places in cold paces with short light presence, like in the north emisphere like Europe and US? If so, how does this happen?
Give thanks,
Mandingo.
RasIene:
Iance and Greetings, Brethren Ayinde. Much Raspect to the I continued academic research. I feel that Information is power...parth of the Rasta mantra: word, sound and Power. Now! I want to know if the research intend to show that all races are result of certain African Tribe migration. And that migration may have caused the spin off of other race from Africa, but over time were able to adopt to climatic condition. All of that happen when the less successful pygmy against the Bantu-s who out maneuvored them. I want to know why you think given Africa's vast land why would they have left Africa for other world? And too why is that one Tribe could succedd while the other fail- considering that they both are from the same Africa land.
"In their study, the research team compared 377 microsatellite markers in DNA collected from 1,056 individuals representing 52 geographic sites in Africa, Eurasia (the Middle East, Europe, Central and South Asia), East Asia, Oceania and the Americas." I have not heard any of the African countries I and I know today mention here.
Brethren Ayinde! how could Idren such as yourself obtain soem of these funds so that we can carry out our own research and gather information of this calibre?
I shall read up more on the links you have provided. It is an interesting point. I would like to know more about that aspect of the DNA. A lot of time brethrens submit to Blood test or paternity test, yet they do not overstand what goes into the interpretation of those results. but give that they only took a "1056 people from 52 different geographic area in Africa. Would not that make the research not a full conclusion or a representative of the African population. I know that Africa has a lot of Tribe, but why just the two mentioned in your post? I'Yah, I hope that you will shed more light as you go Idren. Iance
RasIene.
Ayinde:
Quote
Greetings Ayinde,
I remember you explaining how the melanin has the funtion of protecting the body from the sunlight, absorbing also essential nutrients from the sunlight.
White people got their amount of melanin reduced to adapt to the lack of sunlight, to make them able to use all the light they could get.
Am I right in this interpretation?
Yes you are correct.
The skin is the place where Vitamin D is synthesized using ultraviolet rays to catalyze the reaction. So you need some ultraviolet light to penetrate the skin in order to make Vitamin D. Vitamin D turns out to be critical to your body because it provides the means whereby you absorb calcium from your food in your digestive system. So if you don't have Vitamin D, you can't absorb calcium from your food and you can't build strong bones.
Making the proper skin color turns out to be a balancing act between having enough natural sunscreen to prevent a lot of damage to the contents of the blood system. On the other hand, you have to let in enough ultraviolet light to still permit the formation of Vitamin D in your skin. So people who live in conditions of lower ultraviolet light, away from the tropics and toward the poles, have to have lighter skin than those people who live closer to the tropics or closer to the equator. Those people really have to have darker skin to protect themselves from ultraviolet light.
Those who are sort of in the middle, like inhabitants of most of North America and most of Eurasia, have to have skin that is capable of some level of tanning so that we can protect ourselves from lots of ultraviolet radiation in the late spring and summer. But we can de-pigment ourselves as ultraviolet light becomes less intense in the winter so we can take advantage of the ambient ultraviolet radiation that does exist.
If we look at our earliest Homo sapiens ancestors (about 100 to 150 thousand years ago in eastern Africa), we can reconstruct that those ancestors would have had dark skin to protect themselves from the deleterious effects of ultraviolet light. But those populations began to move out of the tropics and colonize areas that were much less intense in terms of ultraviolet light. As they first moved into the Circum Mediterranean, Western Asia, then onward into Eastern Asia, Europe, Southeast Asia, Australia and so forth, these populations would have to undergo some depigmentation in order for them to be able to synthesize enough Vitamin D in their skin.
Why Skin Comes in Colors
Ayinde:
Another article for consideration
by Clyde Winters
In ancient times a wonderful civilization existed in the Highland regions of Middle Africa. In this wonderful civilization 6000 years ago lived the ancestors of the Dravidians, Black Africans, Elamites and the Sumerians. Today we call this Proto-Saharan civilization the "Fertile African Crescent", because the highland regions in which the Proto-Saharans l lived formed a crescent shape across the Saharan region of middle Africa.
Pastoralism and fishing preceded food production in the ancient Sahara. It appears that a hunter-fisher-gatherer group which clearly specialized in the hunting of animals (as evidenced by the arrowheads) became animal herders, since they were keenly aware of the habits of game and therefore made the shift from hunter-fisher-gatherer to animal husbandry rapidly once climatic conditions in the Sahara made it impossible to collect grains.
Moderate climatic conditions made it possible for the Proto-Saharans to engage in intensive plant domestication. Food surpluses led to the rise of towns and cities, complex political organization. social ranking of individuals in society, and craft specialization as certain clans and ethnic groups became more sedentary.
The linguistic evidence indicates that the Proto-Saharans practiced a form of intensive agriculture characterized by the use of the hoe, related water storage and irrigation techniques plus the application of fertilizers to the cultivated land.
The ability to produce surplus food led to an increase in population, changes in social organization and class distinctions. Naturally, population increases forced the ancestors of the Proto-Saharans to spill over into more marginal areas. This population pressure probably forced many Proto-Saharan clans to domesticate plants and animals to preserve traditional levels of food production.
The ancestors of the Dravidians, Manding and Sumerians were organized into a federal system during the neolithic subpluvial. These early Proto- Saharans made adequate uses of local game and plant life and they established permanent and seasonal settlements around well stocked fishing holes. They lived on plains, punctuated by mountains and numerous points of inundation due to the frequency of rain in the ancient Sahara.
The early ability to find permanent sources of food and shelter during the neolithic by the Proto-Dravidians, and other Proto-Saharans led to increased domestic functioning of the woman, since hunting wild game and the constant need of the Proto-Saharans to provide food and the search for herds of game, as a source of food was no longer that important. The stability of the hearth maintained by the women led to the development of a matriarchal system. In addition to a matrillineal pattern of inheritance among these people, women had equal rights to the men.
Women created agriculture. Thus, the term"Ma",appears in the languages spoken by the descendants of the Proto-Saharans to denote both "mother" and "earth area".
The Proto-Saharans claimed descent from the Maa or Fish Confederation. The Maa Confederation includes the Egyptians, Elamites, Dravidians, Manding and Sumerians. In honor of the great ancestor: Maa, they worshipped a god called: Amun, Amon, or Amma. In honor of this great ancestor the descendants of the Proto-Saharans use the term Ma, to denote greatness or highness, e.g., Manding " Maga" and Dravidian Ma. Other Proto-Saharan tribes claimed direct descent from the great Maa, founder of the Fish Confederation. For example, the Manding call themselves Ma-nde: children of Ma, while the Sumerians were called Ma-Gar-ri (exalted God's children).
The Proto-Saharans share place names. Evidence for shared place names has been discovered by Dr. Vamos-Toth Bator. Dr. Vamos-Toth Bator, calls this ancient civilization ---root culture-- Tamana. The term Tamana can be interpreted in the Manding and Dravidian language as "Strongplace","Stronghold" or "Original Settlement". The term Tamana is one of over 1,000,000 place names Dr. Vamos-Toth has found which link Africa, Asia, and Europe.
The term Tamana, was a popular place name for the Proto-Saharans, as they expanded out of the nuclear Proto-Saharan region, to signify a colonial city or trade center established among hostile alien tribes.
The Proto-Saharans also had their own writing system. This writing system was used by the Dravidians in the Indus Valley, the Manding in the Western Sahara, and the Egyptians.
The ancient Proto-Saharan script was a logo syllabic system. The words used to write this script were monosyllabic.
This writing was engraved on rocks, a stylus was used to engrave wet clay. This view is supported by the fact that the term for writing in Dravidian and Egyptian has supported by the fact that the term for writing in /l/, /r/ or /d/. For a U attached to initial consonants usually /l/, /r/ or /d/. For example, writing in Sumerian was Ru and Shu, Elamite: Talu, Dravidian: Carru and Egyptian: Mdu. These terms agree with the Manding terms for excavate or hollow out: du, do, kulu, tura, etc. This shows that the Proto-Saharan term for writing denoted the creation of impressions on wet clay or hard rock. The Sumerians term for carving was du.
A comparative study of the Proto-Saharan languages (PS), gives us a very clear indication of their cultural traits, at the time of separation. Suzanne Romaine, makes a good case for the separability of the linguistic area of research and that of socio-cultural research and the synchronic with the diachronic historical areas. This use of linguistic data to highlight the cultural history of related groups of speakers, was also supported by Labov , who suggested that people having similar scoio-cultural traits, would also be linguistically similar. As will soon be illustrated in this book, this theory is supported by the analogy between the Dravidian, Manding and Sumerian languages.
It is interesting to note that although the Dravidians, Manding and Sumerians live in varying topography and climate, and in self supporting semi-isolated regions they used the same terms to denote the earliest elements of civilization. Terms which show little phonological divergence. Moreover, these terms are mutually intelligible. This shows that the speakers of these languages came from a common ancestral language: Bafsudraalam.
The early contact between the Dravidians, Manding and Sumerians in the Proto-Sahara led to great resemblances in the area of the cultural lexicon. This is particularly evident in the affinity between culture terms referring to the Proto- civilization of the speakers of these languages. The sedentary lifestyle of the Proto-Saharans emphasize the role of culture as a determinant of linguistic structure and vocabulary.
An examination of the Proto-Saharan languages illustrates that the speakers of these languages lived in cities PS *uru, and had chiefs PS *sar. In addition to living in cities the Proto-Saharans had built extensive roads called PS *sila.
The PS term for people or humanity was PS *oku. The mother of the family was called PS *amma or *ma. and the father was called PS *pa. The children both boys and girls were usually referred to as PS *de/di/du. They lived in houses called PS *-u/*lu.
The Proto-Saharans used the suffix PS *-ta to indicate a place of habitation. Cultivation was called PS *ga(n); cultivatable barren land near water was referred to as PS *de/i(n).
The Proto-Saharans were great sailors. They used celestial navigation to make long voyages. The Proto-Saharans also used boats called PS *kalam.
Hunting was an important aspect of Proto-Saharan life. As a result the bow and arrow was a popular weapon, e.g., arrow PS *kaka.
Many of the long distance voyages made by the Proto-Saharans were made in search of precious metals. The Proto-Dravidians dominated trade in lapis lazuli for hundreds of years. As a result they were familiar with mining. They therefore share the term for digging: Dravidian tulai, Manding du, tyolo, and Sumerian dul, tul,: PS*tul.
These people probably knew about blacksmithy e.g., Tamil: irumbu,Telugu : inamu, Manding: numu, umu "forge". These Proto-Saharans were familiar with many metals including copper: Dravidian uruttiran, Sumerian urdu, and Manding: kura, kuta: PS *urut; gold: Dravidian: kaani, Kaanam, Sumerian: Gush-kin, and Manding: saani, PS *aani; and Steel, Dravidian: alavu, urukku, Elamite: ufat and Manding tuufa PS *ufa.
Above we have discussed many of the cultural first which the Proto-Saharans created in ancient Africa. The linguistic evidence clearly indicates that the Dravidians, Elamites, Black Africans and Sumerians formerly lived in the Highland regions of the Sahara until after the Sahara began to dry up. As the highland regions of the Sahara became a desert the Proto-Saharans spread from middle Africa to America, Europe, Asia and throughout Africa.
http://homepages.luc.edu/~cwinter/proto2.htm
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