New discovery modern Humans China

[D J Thornton]

By Ann Gibbons 14 October 2015 1:00 pm
http://news.sciencemag.org/archaeology/ ... mans-china

For decades, anthropologists have tried to trace the patchy trail left by the earliest modern humans out of Africa. But they have been stymied by gaps in the fossil record or unreliable dates, especially in East Asia. Now, Chinese anthropologists report 47 teeth of Homo sapiens from a cave in southern China, dated to 80,000 to 120,000 years ago. If the dating is accurate, the discovery pushes back the appearance of our species in Asia by at least 30,000 years, wiping out a long-standing picture in which modern humans swept out of Africa in a single wave 50,000 to 70,000 years ago.

“This changes everything. It’s the best evidence we have for modern humans in East Asia this early,” says archaeologist 
Michael Petraglia of the University of Oxford in the United Kingdom, who was not part of the work but has long advocated an early migration out of Africa. Others question the dates. “This case is better than the previous similar claims, but it is not fully convincing,” says paleoanthropologist Yousuke Kaifu of the National Museum of Nature and Science in Tokyo.

Most researchers agree that modern humans arose in Africa and first ventured out of that continent into the Middle East about 120,000 to 90,000 years ago, as shown by skulls from Israel. But H. sapiens remains don’t appear in Europe, East Asia, and Australia until 40,000 to 50,000 years ago. Older fossils in Asia proposed as H. sapiens are controversial. Genetic studies, too, suggest that humanity’s great global expansion began just 50,000 to 70,000 years ago.

But Petraglia and others have unearthed sophisticated stone tools from the Arabian Peninsula and India, persuading him that modern humans left Africa as long ago as 125,000 years, settled in a then-wet Arabia, then pushed into India and eastward (Science, 29 August 2014, p. 994). Skeptics counter that other archaic humans could have made the tools, and that fossils are needed as proof. Read more

[D J Thornton]

Teeth from a cave in China suggest that modern humans lived in Asia much earlier than previously thought, and tens of thousands of years before they reached Europe, researchers say.

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 200,000 years ago in Africa. When and how the modern human lineage dispersed from Africa has long been controversial.

Previous research suggested the exodus from Africa began between 70,000 and 40,000 years ago. However, recent research hinted that modern humans might have begun their march across the globe as early as 130,000 years ago. [See Photos of Our Closest Human Ancestor]

One place that could shed light on the spread of humanity is southern China, which is dotted with fossil-rich caves. Scientists analyzed modern human teeth that they unearthed in Fuyan Cave in southern China's Hunan province, which is part of a system of caves more than 32,300 square feet (3,000 square meters) in size.

Excavations from 2011 to 2013 yielded a trove of 47 human teeth, as well as bones from many other extinct and living animals, such as pandas, hyenas and pigs. The scientists detailed their findings in the Oct. 15 issue of the journal Nature.

The researchers found these teeth are more than 80,000 years old, and may date back as far as 120,000 years. Until now, fossils from southern China confirmed as older than 45,000 years in age that can be confidently identified as modern human in origin have been lacking.

"Our discovery, together with other research findings, suggests southern China should be the key, central area for the emergence and evolution of modern humans in East Asia," the study's co-lead author, Wu Liu, of China's Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, told Live Science.

These newfound teeth are smaller than counterparts of similar ages from Africa and elsewhere in China. Instead, they more closely resemble teeth from contemporary modern humans. This suggests different kinds of humans were living in China at the same time — archaic kinds in northern China, and ones more like modern humans in southern China.

The researchers said these findings could shed light on why modern humans made a relatively late entry into Europe. There is currently no evidence that modern humans entered Europe before 45,000 years ago, even though they made it as far as southern China at least as early as 80,000 years ago. The investigators suggested that Neanderthals might have prevented modern humans from crossing into Europe until after Neanderthals began dying off. Read more
http://www.livescience.com/52481-modern ... urope.html

[D J Thornton]

Fossil finds from China have shaken up the traditional narrative of humankind's dispersal from Africa.
http://www.bbc.com/news/science-environment-34531861
Scientists working in Daoxian, south China, have discovered teeth belonging to modern humans that date to at least 80,000 years ago.
This is 20,000 years earlier than the widely accepted "Out of Africa" migration that led to the successful peopling of the globe by our species.
Details of the work are outlined in the journal Nature.
We need to re-think our models. Maybe there was more than one Out of Africa migration
Dr María Martinón-Torres, UCL
Several lines of evidence - including genetics and archaeology - support a dispersal of our species from Africa 60,000 years ago.
Early modern humans living in the horn of Africa are thought to have crossed the Red Sea via the Bab el Mandeb straits, taking advantage of low water levels.
All non-African people alive today are thought to derive from this diaspora.
Now, excavations at Fuyan Cave in Daoxian have unearthed a trove of 47 human teeth.
Ancient diaspora
"It was very clear to us that these teeth belonged to modern humans [from their morphology]. What was a surprise was the date," Dr María Martinón-Torres, from University College London (UCL), told BBC News.
"All the fossils have been sealed in a calcitic floor, which is like a gravestone, sealing them off. So the teeth have to be older than that layer. Above that are stalagmites that have been dated using uranium series to 80,000 years.
This means that everything below those stalagmites must be older than 80,000 years old; the human teeth could be as old as 125,000 years, according to the researchers.
Image copyrightScience Photo Library
Image caption
Modern humans reached the Levant 125,000 years ago, but this migration has been regarded as a failed foray outside Africa
In addition, the animal fossils found with the human teeth are typical of the Late Pleistocene - the same period indicated by the radioactive dating evidence.
Some fossils of modern humans that predate the Out of Africa migration are already known, from the Skhul and Qafzeh caves in Israel. But these have been regarded as part of a failed early dispersal of modern humans who probably went extinct.
However, the discovery of unequivocally modern fossils in China clouds the picture.
"Some researchers have proposed earlier dispersals in the past," said Dr Martinón-Torres.
"We really have to understand the fate of this migration. We need to find out whether it failed and they went extinct or they really did contribute to later people.
"Maybe we really are descendents of the dispersal 60,000 years ago - but we need to re-think our models. Maybe there was more than one Out of Africa migration."
'Game-changer'
Prof Chris Stringer, from London's Natural History Museum said the new study was "a game-changer" in the debate about the spread of modern humans.
"Many workers (often including me) have argued that the early dispersal of modern humans from Africa into the Levant recorded by the fossils from Skhul and Qafzeh at about 120,000 years ago was essentially a failed dispersal which went little or no further than Israel."
"However, the large sample of teeth from Daoxian seem unquestionably modern in their size and morphology, and they look to be well-dated by uranium-thorium methods to at least 80,000 years. At first sight this seems to be consistent with an early dispersal across southern Asia by a population resembling those known from Skhul and Qafzeh.
"But the Daoxian fossils resemble recent human teeth much more than they look like those from Skhul and Qafzeh, which retain more primitive traits. So either there must have been rapid evolution of the dentitions of a Skhul-Qafzeh type population in Asia by about 80,000 years, or the Daoxian teeth represent a hitherto-unsuspected early and separate dispersal of more modern-looking humans."
Dr Pontus Skoglund, from the department of genetics at Harvard Medical School, told BBC News: "The genetic evidence we have puts strong constraints on some aspects of human history, but less so on the timing of the out of Africa event. Most genetic reconstructions based on modern data relies on assumptions on the mutation rate, for which there are still some real uncertainties.
"In terms of direct genetic evidence, we already have a 45,000 year-old genome from Siberia (Ust Ishim) and a ~40,000 year old individual from Europe (Oase) that are consistent with being from now-mostly-extinct lineages. "
"The conclusion is perhaps that the genetics does allow an 80,000 year old East Asian population to contribute some ancestry to present-day people, but I think not very much. It is a very interesting discovery that is hard to fit in our current thinking, but not impossible. We are just starting to cope with this data point."
Dr Martinón-Torres said the study could also shed light on why it took Homo sapiens another 40,000 years to settle Europe.
Perhaps the presence of the Neanderthals kept our species out of westernmost Eurasia until our evolutionary cousins started to dwindle in number. However, it's also possible that modern humans - who started out as a tropical species - were not as well-conditioned as the Neanderthals for the icy climate in Europe.
She noted that while modern humans occupied the warmer south of China 80,000 years ago, the colder regions of central and northern China appear to be settled by more primitive human groups who may have been Asian relatives of the Neanderthals.