Anthropology
Related: About this forumNew DNA Analysis Shows Aboriginal Australians Are the World's Oldest Society
The group was the first to split after a single wave of migration out of Africa took place between 51,000 and 72,000 years ago, study shows
By Danny Lewis
SMITHSONIANMAG.COM
SEPTEMBER 23, 2016
For centuries, Aboriginal Australians have said they belonged to the oldest sustained civilization on the face of the Earth, citing their culture and history of oral storytelling that stretches back tens of thousands of years. Now, one of the most extensive analyses of Indigenous Australian DNA to date suggests that they've been right all along.
The ancestors to modern humans first arose in Africa, but the question of where and when they began spreading out from the continent has long plagued scientists and archeologists alike. While Homo sapiens are far from the first human species to begin exploring other parts of the planet (other, older species like the Neanderthals and Denisovans made it out first), the question has long been whether the ancestors of modern non-Africans left in waves or all at once, Emily Benson reports for the New Scientist.
Nailing down the approximate times that ones ancestors left Africa is tricky business. Previous research has shown that humans began splitting into different genetic groups about 200,000 years ago, long before they first began exploring other continents. By analyzing DNA from 787 people from 270 modern cultures spread across the world, a group of scientists identified and tracked ancient genetic mutations that they believe mark when different ethnicities diverged as their ancestors settled across the world, Benson reports.
Using this genetic tracing, the researchers suggest that the first Homo sapiens began leaving Africa between 51,000 and 72,000 years ago. And the ancestors of Indigenous Australians were the first group to split off from that migration. While the ancestors of European and Asian people diverged about 42,000 years ago, the precursors to todays Indigenous Australians and Papuans diverged 58,000 years ago to head east, George Dvorsky reports for Gizmodo.
More:
https://www.smithsonianmag.com/smart-news/dna-tests-suggest-aboriginal-australians-have-oldest-society-planet-180960569/
SunSeeker
(53,720 posts)wnylib
(24,449 posts)a water barrier, which makes the ancestors of indigenous Australians likely the first humans to cross open sea in a boat or raft.
Lower sea levels due to glaciation exposed continental shelf land so that current islands in southern Asia were linked together and to the mainland except for a gap of about 50 to 70 miles beteen those Asian land areas and Australia. So they were either good at boating or excellent swimmers.
SunSeeker
(53,720 posts)The only ancient people we know for sure crossed open sea to reach their new homeland were the Polynesians. It still blows my mind how Hawaii, a rock in the middle of the Pacific 2,000 miles from the nearest land mass, was populated.
wnylib
(24,449 posts)I first learned about this a few years back at another website when chatting with an Australian anthropologist. Sumatra, Java, and Borneo, plus smaller islands in that area were all connected in a mass sometimes called Sundaland. This mass was connected to the southeast Asian mainland (Malaysia, etc.)
The other land mass, referred to in the linked Smithsonian article, was Sahul - New Guinea and Australia connected to each other. (No, my memory is not that good. I had to look up their names again.)
The land mass that Australia belonged to was never connected to the other one that extended from mainland SE Asia, but at some periods during glaciation, the distance of water between them was only 90 kilometers. Other times it was greater.
The original theory that I learned from the Australian anthroplogolist was that people traveled by land to the furthest extent of the islands connected to each other and mainland Asia, then eventually made the water trip to the Sahul and spread into what is now Australia before Australia and New Guinea were separated.
Later, another theory was that, since the connections of the islands in the SE Asian land mass fluctuated as glaciation and water levels fluctuated, people might have traveled very short distances over shallow water from one island to another. From those experiences they would have gained rafting or boating skills to go the much further distance to Australia/Sahul.
I questioned calling the trip to Australia "open sea." I learned that it was called that because, even at its narrowest, it was still a great leap in water travel for early humans. They left one land mass for another, without hugging coastlines, to deal with much deeper water and currents they had not encountered before when only hopping a couple miles between islands. It was a technological leap.
The earliest evidence for humans in Australia is over 60,000 years ago, but it consists of mostly tools and no human fossils. The earliest human remains in Australia date to about 43,000 years ago. Older remains in coastal areas were probably lost when sea levels rose.