Posted by:
anybody
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Date: April 04, 2021 10:19AM
Forget snakes, apples, and angels with flaming swords.
A changing climate forced our distant ancestors to migrate.
https://en.wikipedia.org/wiki/Lake_Makgadikgadihttps://i.redd.it/txoyyxkvvvvz.jpghttps://www.telegraph.co.uk/science/2019/10/28/homeland-humans-lush-garden-eden-south-zambezi-river/The homeland of all humans was a lush Garden of Eden situated to the south of the Zambezi River, in northern Botswana, a major study of DNA has concluded.
For the first time, researchers have traced back the maternal genetic lineage of anatomically modern humans (Homo sapiens sapiens) and found it most closely resembles people living in a small area of southern Africa.
Although the area now sits in the Kalahari desert, the region was once covered by an enormous lake, around in which our ancestors thrived for 70,000 years.
But a dramatic change to the climate caused by an alteration in the orbital tilt of the Earth allowed populations to move northwards.
Professor Vanessa Hayes, a geneticist at the Garvan Institute of Medical Research in Australia, said: “It has been clear for some time that anatomically modern humans appeared in Africa roughly 200,000 years ago but what we haven’t known is where that homeland is.
“What has been long debated is the exact location of this emergence and subsequent dispersal of our earliest ancestors.
“It’s an extremely large area, it would have been very wet, very lush, it would have provided a suitable habitat for modern humans and wildlife to have lived.
“It’s something that fascinates all humans. If we really want to understand our future we need to understand our past, who we are and where we all come from.”
Professor Hayes and colleagues collected blood samples from study participants in Namibia and South Africa and looked at their mitochondrial DNA (mtDNA) which comes through the maternal line.
As mtDNA is passed from mother to child through the egg cell, so its sequence stays the same over generations, making it a useful tool for looking at maternal ancestry.
The team focused their research on the L0 lineage - modern human's earliest known population - and compared the complete DNA code (mitogenome) from different individuals - including other sub lineages across various locations in Africa - to see how closely they were related.
The researchers then combined genetics with geology and climatic physics, to paint a picture of what the world looked like 200,000 years ago.
Geological evidence suggests the homeland region once housed Africa's largest ever lake system, known as Lake Makgadikgadi.
And climate computer model simulations indicate that "the slow wobble of Earth's axis" brought "periodic shifts in rainfall" across the region.
Professor Axel Timmermann, a climate scientist at Pusan National University in South Korea, said: "These shifts in climate would have opened green, vegetated corridors, first 130,000 years ago to the north east, and then around 110,000 years ago to the south west, allowing our earliest ancestors to migrate away from the homeland for the first time."
Prof Hayes concluded: “We observed significant genetic divergence in the modern humans' earliest maternal sub-lineages that indicates our ancestors migrated out of the homeland between 130,000 and 110,000 years ago.
“The first migrants ventured north east, followed by a second wave of migrants who travelled south west.
“A third population remained in the homeland until today.”
The research was published in the journal Nature.
Edited 3 time(s). Last edit at 04/04/2021 10:43AM by anybody.