Israel's raid on Entebbe was almost a disaster
- В ТРАНСТЕКСТЕ сбой. Ты даешь мне ключ.
Все очень все. Разница между ураном и плутонием.
Did creation begin in Africa? The model often holds that once these people were out of Africa, a brief period of interbreeding with Neanderthals occurred, helping to explain why individuals of European and Asian heritage today retain archaic human DNA. Rewriting the history of man's migration out of Africa: Researchers suggest that early humans began crossing to Eurasia as early as , years ago. The traditional 'Out of Africa' model suggests that modern humans evolved in Africa and then left in a single wave around 60, years ago.
But advances in DNA testing and other fossil analysis techniques show that humans actually arrived in Asia much earlier than previously thought, according to a review of recent research.
The study also claims migrants dispersed across Eurasia in a number of waves across tens of thousands of years, interbreeding with their human-like cousins along the way.
The team sequenced the genomes of seven individuals who lived in southern Africa years ago. The three oldest individuals dating to years ago were genetically related to the descendants of the southern Khoe-San groups, and the four younger individuals who lived years ago were genetically related to current-day South African Bantu-speaking groups.
The authors estimate the divergence among modern humans to have occurred between , and , years ago, based on the ancient Stone Age hunter-gatherer genomes. The deepest split time of , years ago represents a comparison between an ancient Stone Age hunter-gatherer boy from Ballito Bay on the east coast of South Africa and the West African Mandinka.
Scientists working in Daoxian, south China, have discovered teeth belonging to modern humans that date to at least 80, years ago. This is 20, years earlier than the widely accepted "Out of Africa" migration that led to the successful peopling of the globe by our species.
This discovery yields new information about the dispersal of modern humans from Africa to the rest of the world, and could shed light on how modern humans and Neanderthals interacted, the scientists added. Modern humans first originated about , years ago in Africa.
When and how the modern human lineage dispersed from Africa has long been controversial. A comparison with genetic material from today's Africans reveals how our ancient ancestors mixed and moved around the continents. This finding may helps scientists reconstruct how humans evolved as they wandered across the globe, the researchers added.
Modern humans first arose about , years ago in Africa south of the Sahara. When and how the modern human lineage crossed the Sahara and dispersed from Africa has long been controversial. Previous research suggested the exodus from Africa started between 70, and 40, years ago. However, a recent study hinted that modern humans might have begun their march across the globe as early as , years ago, and continued their expansion out of Africa in multiple waves.
Our modern human ancestors evolved in Africa, then swept across Eurasia beginning some 60, to 50, years ago. Now, a pair of American archaeologists claim to have uncovered the route those early Homo sapiens took on their way to populating the planet. By following the broken trail of stone tools that modern humans left behind like bread crumbs marking their path, researchers propose that our ancestors took a circuitous path through Arabia, pausing there for some 50, years when it was a green oasis.
Then they journeyed on to the Middle East, where they first encountered Neanderthals. This migration led to the colonization of the entire planet by our species, as well as the extinction of other human groups such as the Neanderthals. The skull from Manot Cave dates to 55, years ago and may be the closest we've got to finding one of the earliest migrants from Africa. Modern humans originated about , years ago in Africa.
However, scientists have long debated when and how the modern human lineage spread out of Africa. They have discovered there are marked differences in the way stone tools were made, reflecting a diversity of cultural traditions. The study has also identified at least four distinct populations, each relatively isolated from each other with their own different cultural characteristics.
The new findings are in line with earlier estimates, but contradict a more recent study that put humans' first exodus from Africa least , years ago. The new results "agree with what we know from archaeology," said study co-author Alissa Mittnik, a biologist at University of Tubingen, in Germany.
This expansion, detailed by three Stanford geneticists, had a dramatic effect on human genetic diversity, which persists in present-day populations.
As a small group of modern humans migrated out of Africa into Eurasia and the Americas, their genetic diversity was substantially reduced. The discoveries suggests that at least three distinct species of humans co-existed in Africa. The research adds to a growing body of evidence that runs counter to the popular perception that there was a linear evolution from early primates to modern humans. Although modern humans, Homo sapiens, are the only human species alive today, the world has seen a number of human species come and go.
Other members perhaps include the recently discovered "hobbit" Homo floresiensis. The human lineage, Homo , evolved in Africa about 2. For the first half of the last century, conventional wisdom was that the most primitive member of our lineage was Homo erectus, the direct ancestor of our species. However, just over 50 years ago, scientists discovered an even more primitive species of Homo at Olduvai Gorge in Tanzania they dubbed Homo habilis, which had a smaller brain and a more apelike skeleton.
The finds, announced in the prestigious scientific journal Nature on August 9, include a face, a remarkably complete lower jaw, and part of a second lower jaw. Following Genetic Footprints out of Africa: Using mitochondrial DNA analysis, which traces the female line of descent and is useful for comparing relatedness between different populations, the researchers compared complete genomes from Arabia and the Near East with a database of hundreds more samples from Europe.
They found evidence for an ancient ancestry within Arabia. This date is considerably older than geneticists have put forth for the modern human exodus from Africa, who estimate the dispersal of our species occurred between 70, and 40, years ago. Even more surprising, all of the Nubian MSA sites were found far inland, contrary to the currently accepted theory that envisions early human groups moving along the coast of southern Arabia.
They determined some of the human X chromosome originates from Neanderthals, but only in people of non-African heritage. One key finding from the Wellcome Trust Sanger Institute's study is that African and non-African populations continued to exchange genetic material well after migration out-of-Africa 60, years ago. This shows that interbreeding between these groups continued long after the original exodus.
Climate change, reduction in populations and harsh conditions may have caused and maintained the separation. Now, University of Utah geologists are calling renewed attention to the idea that ground movements formed mountains and valleys, creating environments that favored the emergence of humanity.
Scientists had always thought the exodus from Africa around 70, years ago took place along a northern route into Europe and Asia. But according to a genetic study, early modern humans followed the beach, possibly lured by a seafood diet.
They quickly reached Australia but took much longer to settle in Europe. That must be it! The road would be described by Kenyans as "corrugated" meaning that we had to get out in some places to look for it on our way to the Turkana region--not too far from where the most ancient hominid fossils had been found by Richard Leakey, Director of the National Museums. We had heard of an ancient astronomy site in this region made up of basalt pillars that were magnetic, so needed to be remeasured using something other than compasses.
We had camped with hippos at Lake Nivasha, swum in Lake Turkana known to have over 3 million crocodiles in it, watched as several million pink flamingos had taken to the air around Lake Nakuru, and seen the migration of a couple million wildebeests across the Masaai Mara plains, all on our roundabout safari to this ancient astronomy site. The pillars were known as "Namoratunga" or "stone people" in the Turkana language. They had been said to have been built for an astronomical purpose, to reckon the Borana calendar, and were reputed to be a couple of thousand years old.
They had petroglyphs on them, some matching the ancient property symbols of the Kush, a people of the Sudan who had once conquered Egypt in the 8th Century B. From maps of ancient Kush, I knew that the front of almost all their pyramids appeared to face the star Sirius , which has not changed its position in the sky very much for the last several thousand years.
We had a description of the Borana calendar, but this did not make astronomical sense. For example, the new year of the Borana calendar was said to occur when the star beta Triangulum was "in conjunction" with the new moon new, give or take a couple of days. A new moon is, of course, close to the sun i. However, the star beta Triangulum is a 3rd magnitude star and could not been seen in twilight. Thus, we could not even get the Borana new year started according to the description we had from anthropologists.
The fossils help fill a huge gap in the evolutionary history of African mammals known as the "missing years," shedding light on the origin and distribution of the famed beasts that roam Africa today. The crania of two adults and a child, all dated to be around , years old, were pulled out of sediments near a village called Herto in the Afar region in the east of the country.
They are described as the oldest known fossils of modern humans, or Homo sapiens. What excites scientists so much is that the specimens fit neatly with the genetic studies that have suggested this time and part of Africa for the emergence of mankind. Three fossilized skulls unearthed in Herto, Ethiopia are said by scientists to be among the most important discoveries ever made in the search for the origin of humans.
The fossilized skulls of two adults and one child discovered in the Afar region of eastern Ethiopia have been dated at , years, making them the oldest known fossils of modern humans, or Homo sapiens. The skulls, dug up near a village called Herto, fill a major gap in the human fossil record, an era at the dawn of modern humans when the facial features and brain cases we recognize today as human first appeared.
The fossils date precisely from the time when biologists using genes to chart human evolution predicted that a genetic "Eve" lived somewhere in Africa and gave rise to all modern humans. The most ancient populations include the Sandawe, Burunge, Gorowaa and Datog people who live in Tanzania.
Researchers found a very high amount of genetic variation, or diversity, between the mitochondrial DNA of different individuals in these populations.
Mitochondrial DNA is passed down exclusively through the maternal line. The longer a population has existed, the more variation accumulates in its DNA lineages.