This watery barrier—likely not more than five kilometers wide—would have been but a small obstacle for a group of modern humans accustomed to navigating African lakes with boats and rafts. But this short crossing, enabled by coincidental climate change, might have led the species—possibly for the first time— out of Africa and into Arabia, and eventually deeper into Asia, Europe and the rest of the globe.
Genetic mapping of Y chromosome data indicates that a third migration out of Africa occurred around 55, BP during a warming trend. These elements then diverged in separate directions. Some headed westward along the northern shores of the Caspian and Black in to Europearriving around 40, BP.
Others headed eastward through Siberia, China, and Mongolia to Beringia, where the existence of a land bridge enabled them to cross into Alaska and North American by 25, BP. Other migrating elements independently moved eastward along the Indian Ocean to repopulate those areas abandoned during the earlier migration.
This is the only viable explanation for the marked genetic divide that exists between people living today in east Asia, New Guinea, and Australia, and those living in India and farther west.
This picture is complicated even more by genetic markers indicating that other humans descended from the time of the earlier migration in 84, BP had by this time likewise made their way to China and Japan. These humans also migrated across Beringia into the Americas.
Before this occurred, however, another glacial era descended on the planet between 35, and 24, BP. The millennia between 20, and 18, BP in particular represented a period of unrelenting cold throughout the planet, culminating in the 3km tall ice sheets mentioned above.
Sea levels plunged by m. The LGM appears to have wiped out the Neanderthal populations in Europe and unquestionably impaired the progress of modern humans as well. Fortunately, these latter populations were sufficiently well situated by this time, and adequately armed with tools and technologies to hunker down in their various regions of the world and survive.
It is important to recognize that the bulk of the modern human population remained in Africa throughout these eras.
This had an enormous impact on the way humans evolved. One researcher compared the repeated exodus of small groups of modern humans to the equivalent of removing the playing cards, 7, 8, and 9, from a deck of Those populations that remained in central Africaby and large thrived in its moderate climate, continued to mix their gene pool, and otherwise developed attributes of "complex societies.
Although the archaeological evidence for these attributes of modern human cultures does not occur in combination at any one place or time in Africathe overall picture suggests that their packaging was assembled prior to the departure of migrating bands to distant continents around 84, BP.
These same attributes become manifested as rock art in Australia, cave art in Spain and France, a bone flute found in Germany 39, BPkiln-fired ceramic figurines in Moravia 20, BPkiln-fired pottery in Japan 14, BPand exotic grave good in the Middle East and Europe, the last mentioned demonstrating the existence of social hierarchy and trading networks.
What is more, the variability of the Pleistocene era with its repeated, sustained periods of intense cold inevitably reduced those populations that migrated out of Africa significantly.
Fluctuations in human populations had a huge impact on the rate at which natural selection operated, leading to a phenomenon known as genetic drift. During genetic drift decline in breeding numbers induced changes in the genetic composition of an isolated human population.
As population levels fell to very low numbers, simple chance allowed some genetic variations to spread through the surviving population in lieu of others that disappeared altogether. As human populations declined everywhere except Africa aroundBP, for example, those small elements that survived would have found themselves dispersed into geographically separated groups.
As populations rebounded tens of thousands of years later, each group started from what was essentially a separate genetic base. In Africa the DNA evidence indicates that these separated elements of modern humans continued to mix with one another as their populations expanded and merged.
In essence they forged a genetic bottleneck out of which all non African based populations of modern humans ultimately arose.
It is generally assumed, for example, that such a bottleneck occurred aroundBP for the reasons given above.Apr 14, · Blombos Cave is a South African coastal site located KM east of Cape Town. It is currently the oldest known site containing solid evidence of symbolic thinking and behavior by Homo sapiens, with its earliest faunal and archaeological deposits dated to the Middle Stone Age period between ,, BC. .
Middle Eastern Stone Age Tools Mark Earlier Date for Human Migration out of Africa. Thanks to climatic shifts, early modern humans might have crossed a shallow sea from Africa to a verdant Arabian.
Paleolithic settlement Earliest developments The period of human activity to the end of the last major Pleistocene glaciation, about bce, is termed the Paleolithic Period (Old Stone Age); that part of it from 35, to bce is termed the Upper Paleolithic.
The Stellenbosch and Fauresmith together constitute what is called the South African Older Stone Age, a period roughly corresponding to the Lower and Middle Paleolithic stages of Europe.
|Paleolithic||Paleolithic settlement Earliest developments The period of human activity to the end of the last major Pleistocene glaciation, about bce, is termed the Paleolithic Period Old Stone Age ; that part of it from 35, to bce is termed the Upper Paleolithic. The climatic record shows a cyclic pattern of warmer and colder periods.|
On the other hand, the South African Middle Stone Age belongs to the later part of the Upper Pleistocene. It is characterized by a series of more or less contemporary flake-tool assemblages, each of which displays local features.
Discoveries of the Paleolithic Age By Maria Kielmas; Updated April 23, As the earliest part of the Stone Age, the Paleolithic era derives its name from the Greek words “paleos,” meaning “old,” and “lithos,” meaning “stone.”.
of Africa, this time is known as The Paleolithic Age (Old Stone Age) •These people survived by hunting and gathering. II. Obtaining Food •Food supply and Population is directly related •Humans had a very short life expectancy •Childhood illnesses .