All modern humans may have descended from people in what is today Botswana, according to scientists.
Researchers think they first discovered the & # 39; cradle of humanity & # 39; where the first modern humans evolved before spreading around the world.
They are believed to have flourished in the prehistoric wetland of Makgadikgadi – Okavango, south of the Zambezi River.
A study of DNA records and migration patterns has proven, scientists say, that the genetic root of all modern humans has come from this region for 200,000 years.
The swamp was a hot, lush green garden of Eden, in which early humans prospered before migrating when a wobble on the earth's axis 130,000 years ago caused the climate to dry up.
And direct descendants of these pioneers can still be found living in the arid Kalahari desert today.
The first humans are believed to have developed in the prehistoric wetland of Makgadikgadi – Okavango, just south of the Zambezi River. Their direct descendants – the Khoe San people – still live there today.
The Zambezi River flows into Victoria Falls near the Khoe San homeland of Botswana
Researchers believe that this area, which is now Makgadikgadi Pans National Park, is where the last common ancestors of modern humans around the world can be traced.
Scientists say all the genes of modern humans can be traced back to a population that lived in Makgadikgadi's prehistoric wetland – Okavango, just south of the Zambezi River – the area is now the arid Makgadikgadi saline (photo) and most of people migrated far away when the climate changed
"It has been clear for some time that anatomically modern humans appeared in Africa about 200,000 years ago," said lead researcher Professor Vanessa Hayes.
"The exact location of this emergency and the subsequent dispersal of our earliest ancestors have long been debated."
Professor Hayes of the University of Sydney has studied the DNA of more than 1,200 living African peoples to identify the origin of modern humanity.
She collected samples from people named Khoe San, who live in rural Africa and who are known to be most closely related to the original humans, and people genetically linked to them.
Like the once flourishing wetland is now an arid saline (but comes alive again after the rains)
When humans first lived there, the Makgadikgadi – Okavango Wetland, south of the Zambezi River, was a perfect prosperous oasis for the development of life.
But the climate has changed, drying up the land and making the wetland become what is now a salt and desert region, and forcing the first humans to migrate.
The area is now covered by the Makgadikgadi Pans National Park, which houses one of the largest salt marshes in the world.
For much of the year, the only life that can survive in pans is a thin layer of algae, but after annual rainfall it becomes an important habitat for migrating animals and birds, including one of the largest zebra populations in the world. Africa.
The rainy season also brings migratory birds such as geese, ducks and large white pelicans. The area also houses one of two large flamingos breeding populations in southern Africa.
His team was able to trace common ancestors from all distinct groups to the area of Makgadikgadi in Botswana, which they considered the origin of man.
The results, published in the Nature magazine, add existing geological and fossil evidence that proves that Lake Makgadikgadi was home to early humans.
In the past, scientists have suggested that smaller pockets of humans evolved in various parts of Africa before spreading.
But Professor Hayes said the original humans evolved in the Makgadikgadi – Okavango wetland and remained there for 70,000 years.
"There was a very big lake," she said. "When modern humans arrived, he was splitting into smaller ones – creating a swamp."
And she claims that & # 39; green corridors & # 39; vegetation grew out of the wetland, which developed from a lake twice the size of Lake Victoria, with 23,000 square miles in Tanzania and Uganda, allowing people to migrate northeast and southwest.
Wetlands are one of the healthiest life-sustaining ecosystems and would have been abundant enough for the human species to settle.
The climate then changed, drying up the land and making the wetland become what is now a salt and desert region – this forced people to migrate.
Professor Hayes said: “The first migrants ventured into the northeast, followed by a second wave of migrants traveling southwest.
& # 39; A third population remained in their homeland to this day.
"In contrast to northeastern migrants, southwestern explorers seem to flourish, experiencing steady population growth."
Professor Hayes and her colleagues suggest that when the climate changed about 130,000 years ago and the wetlands where humans lived began to dry up, they migrated to the northeast (blue and green arrows) and southwest (deep purple arrow)) from Africa. L0a, L0k and L0d1 & # 39; 2 are different variations of the original ancestral genes known as L0
People still live in the salt flats of Makgadikgadi, Botswana. These are groups like these whose DNA gave scientists insight into how modern humans might have been born of populations in southern Africa. (Photo: A group of Basarwa hunters / gatherers set off on a salt pot forage expedition together)
The researchers collected samples from people named Khoe San, who live in rural Africa and are known to be closest to the original humans.
Professor Vanessa Hayes discussing the significance of the region with the head ǀkun ǀkunta of an extended Ju / ho hoansi family – Ikun is one of over 1,000 Africans who allowed their DNA to be analyzed to trace the roots of modern man.
The researchers tracked different populations of the KhoeSan people, which are known to be closest to the first modern humans that emerged about 200,000 years ago in Africa.
What do we know about our ancestors?
Four important studies in recent times have changed the way we view our ancestral history.
The Simons Genome Diversity Project Study
After analyzing the DNA of 142 populations worldwide, the researchers conclude that all modern humans living today can trace their ancestors to a single group that emerged in Africa 200,000 years ago.
They also found that all non-Africans appear to be descended from a single group that separated from the ancestors of the African hunters about 130,000 years ago.
The study also shows how humans appear to have formed isolated groups in Africa, with populations on the continent separating.
KhoeSan in South Africa, for example, split from Yoruba in Nigeria about 87,000 years ago, while Mbuti split from Yoruba 56,000 years ago.
Study of the Human Genome Diversity Panel of the Estonian Biocenter
This study examined 483 genomes from 148 populations worldwide to examine the spread of Homo sapiens outside Africa.
They found that indigenous populations in modern Papua New Guinea owe two percent of their genomes to a now extinct group of Homo sapiens.
This suggests that there was a distinct wave of human migration outside Africa about 120,000 years ago.
The Australian Aboriginal Study
Using genomes from 83 Australian Aborigines and 25 New Guinea Papuan, this study examined the genetic origins of these early Pacific populations.
These groups are thought to have descended from some of the first humans to leave Africa and raised questions about whether their ancestors were from a migration wave prior to the rest of Eurasia.
The new study found that the ancestors of modern Australian and Papuan Aborigines separated from Europeans and Asians about 58,000 years ago after a single migration out of Africa.
These two populations later diverged about 37,000 years ago, long before the physical separation of Australia and New Guinea some 10,000 years ago.
The Study of Climate Modeling
Researchers at the University of Hawaii at Mānoa have used one of the first models of integrated human-climate migration computers to recreate the spread of Homo sapiens over the last 125,000 years.
The model simulates glacial eras, abrupt climate change and captures the arrival times of Homo sapiens in the Eastern Mediterranean, Arabian Peninsula, Southern China and Australia, in close agreement with paleoclimatic reconstructions and fossil and archaeological evidence.
They found that modern humans first left Africa 100,000 years ago in a series of slow-moving migration waves.
They estimate that Homo sapiens arrived in southern Europe about 80,000 to 90,000 years ago, much earlier than previously thought.
The results challenge traditional models that suggest that there was a single exodus in Africa about 60,000 years ago.
Their success was probably adaptation to marine fodder – even learning how to harvest seafood, including fish, with their hands.
Professor Hayes's research is based on DNA studies of people living in southern Africa, which allowed them to track the proximity of people.
She studied something known as mitochondrial L0 DNA, which people inherit from her mother.
"Mitochondrial DNA acts as a time capsule of our ancestral mothers, slowly accumulating change over generations," she said.
"Comparison of the complete DNA code, or mitogenome, of different individuals provides information on how closely they are related."
His international team collected blood samples from 1,217 people to establish a comprehensive catalog of the 'L0' lineage.
Professor Hayes said: This allowed us to identify the ancestral homeland of all human beings. This is the first time the exact location has been identified.
Professor Hayes learns how to set fire to Ju'anans hunters in the now dry land of Namibia's Great Kalahari
Makgadikgadi Lake, once covered …
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