Neanderthals And Denisovan’s Were Mixing With Homo Sapiens

(THIS ARTICLE IS COURTESY OF CNN)

 

Neanderthals, Denisovans and our ancestors were mixing and mingling a long time ago — and some of our genetics can be traced back to these archaic humans.

In Asians, as much as 3% of an individual’s DNA may be Neanderthal. For Europeans, it’s as much as 2%. A new study has found that our ancestors interbred with two distinct Denisovan populations, increasing the probability of the presence in modern populations of DNA inherited from this ancient and mysterious people.
The study, using a new genome-analysis method to compare whole genomes of humans with Denisovans, was published in the journal Cell on Thursday.
“It is amazing that we can look into human history via current-day human genetic data, and determine some of the events that happened in the past,” study author Sharon Browning wrote in an email. Browning is a research professor with the University of Washington’s Department of Biostatistics.
“In particular, in this study we found two distinct episodes of Denisovan admixture, which adds to what was previously known about the contribution of Neanderthals and Denisovans to our genomes today.”

Denisovans pose questions

Denisovans pose particular questions for scientists because researchers have only a few bones that even point to their existence: a finger bone, toe bone and a couple of teeth. Fossilized DNA sequenced from those bones, recovered in Siberia, has allowed us to learn more about them. But we still don’t know what these extinct hominins looked like.
Neanderthal and Denisovan DNA was sequenced completely for the first time in 2010, which led to the initial discovery that they were interbreeding with our ancestors. Studies found that the population of Oceania and Papua New Guinea received the most DNA from Denisovans, around 5%.
Fifty thousand years ago, as modern humans moved out of Africa, they encountered Neanderthals and Denisovans, and the “admixing” happened. But pinning down exactly where it happened has proved difficult.
It was especially puzzling given that the fossils were found in Siberia, but Denisovans are most strongly connected to Oceania.
Denisovan ancestry was also present in Asia, although researchers believed that this occurred through migration from Oceania.
Comparing the Denisovan genome to that of 5,600 Europeans, Asians, Americans and Oceanians painted a different picture.
The data showed that Denisovans were even more closely related to modern East Asians, specifically Han Chinese, Chinese Dai and Japanese, than those from Papua New Guinea. And this second set of Denisovan ancestry was different from Oceanians and Papuans.
“It makes it clear that there were distinct populations of Denisovans, rather than a single population,” Browning said. “The fact that these populations had diverged somewhat from each other suggests that the two populations were not mixing very often with each other, perhaps due to geographical separation.”
A possible explanation is that our Oceanian ancestors encountered a southern group of Denisovans, while East Asians met a northern group.
“(This) led people to suspect that Denisovans did not just live in Siberia, but also lived elsewhere in Asia, somewhere south along the likely routes that the ancestors of Oceanians may have taken to get to Oceania,” Browning said. “This study makes this hypothesis look very likely.”
This could also mean that there were more than two distinct episodes of Denisovans mixing with modern humans, which Browning believes future analysis could reveal.
“A major novel finding is that some populations (East Asians) have evidence of multiple introgression related to Denisovans while a few others (South Asians, Papuans) have evidence of a single Denisovan introgression,” Sriram Sankararaman said in an email. “The Denisovan ancestry in South Asians is quite diverged from the sequence Denisovan while the additional component in East Asians is quite close. This suggests a complex interaction pattern of the Denisovans and modern human populations in mainland Asia.”
Follow CNN Health on Facebook and Twitter

See the latest news and share your comments with CNN Health on Facebook and Twitter.

Sankararaman, who was not involved in the study, has worked on Denisovan research and is an assistant professor at the University of California, Los Angeles, in the department of computer science and the department of human genetics.
Going forward, Browning and her colleagues plan to study other populations to look for signatures of admixture with archaic humans besides Neanderthals and Denisovans.
“I’d love to delve further into Neanderthal ancestry, and understand why East Asians have a higher rate of Neanderthal ancestry — around 3% — compared to Europeans — around 2%,” Browning said.
“It has been hypothesized that the extra Neanderthal ancestry in East Asians is due to an additional admixture event, but we didn’t find a clear sign of that in our study. That doesn’t rule out this possibility — we might need to dig a little deeper to find it.”

Very Old Tools Found In India: Question Is, Who Made Them

(THIS ARTICLE IS COURTESY OF THE WASHINGTON POST)

 

Very old, very sophisticated tools found in India. The question is: Who made them?

 February 1 at 9:40 AM 

Artifacts uncovered in the excavation at Attirampakkam. (Sharma Center for Heritage Education)

Humanity’s origin story has gotten increasingly tangled in recent years: New discoveries suggest that Homo sapiens interacted and interbred with other species and ventured out of Africa in more than one wave. Researchers have compared the ancient world to J.R.R. Tolkien’s Middle Earth — but instead of hobbits, dwarves and elves, our planet had modern humans in Africa, Neanderthals in Europe, Homo erectus in Asia.

Now, a treasure trove of ancient stone tools suggests that humans’ circuitous path to modernity also wound through India.

In a paper published Wednesday in the journal Nature, researchers described thousands of stone implements uncovered at Attirampakkam, an archaeological site in southern India. The tools span about a million years of history, they say, and illustrate the evolution of big, blunt hand axes into finely sculpted stone points. Starting about 385,000 years ago — long before modern humans are thought to have arrived in India — it appears that an advanced toolmaking culture was developing there.

How did these techniques reach India so early? “That’s the multimillion-dollar question,” said archaeologist Shanti Pappu, founder of the Sharma Center for Heritage Education and a co-author of the report.

No remains were found alongside the Indian tools, meaning it’s impossible to determine whether the tools were produced by modern humans or one of our hominin cousins. If they were produced by members of our species, it would significantly shift the timeline of human evolution. But that’s a big “if,” Pappu acknowledged.

At the very least, she said, the discovery suggests “complex interactions” between the mystery hominins in India and their relatives around the world.

“It shows that simple linear narratives of dispersal only at certain time periods is incorrect,” Pappu said.

Modern humans evolved in Africa, and the oldest known bones that could feasibly belong to our species were found in a Moroccan cave and dated to 300,000 years ago. The recent discovery of human fossils in an Israeli cave suggests that we may have ventured into other continents as early as 194,000 years ago.

 0:54
Early humans coexisted with human-like species 300,000 years ago in Africa

Scientists in South Africa unveil the first evidence that early humans co-existed with a small-brained human-like species thought to have been extinct in Africa at the time. 

Upon leaving Africa, Homo sapiens would have encountered an array of distant relatives. Paleoanthropologists believe the first hominins left Africa about 1.7 million years ago, although there’s some dispute about what species those early migrants belonged to.

With so few fossils available, reconstructing the story of human evolution and migration is a bit like trying to solve a jigsaw puzzle when you have just a handful of middle pieces and no edges or corners. Often, scientists must trace the movements of our ancestors through the stone tools we created.

The first hominins to leave Africa — whoever they were — carried with them oval- and pear-shaped hand axes used to pound and scrape food — a technology called Acheulean. The oldest tools found at Attirampakkam, which are more than 1 million years old, were crafted in this tradition.

But in a second batch of implements uncovered from a rock layer that spans 385,000 to 172,000 years ago (plus or minus about 50,000 years on either end), those heavy hand axes give way to smaller, more sophisticated points. One of the points even appears to have a groove that would allow it to be affixed to some kind of projectile, like a spear.

This kind of technology has long been associated with Neanderthals and Homo sapiens in Europe, the Middle East and Africa, and it wasn’t thought to have arrived in India until humans reached south Asia about 100,000 years ago. Known as Levallois, this technique is associated with significant advances in human cognition, because such tools can’t be crafted without the ability to think abstractly and plan ahead.

Alison Brooks, a paleoanthropologist at George Washington University, said she’s not convinced that the smaller tools described by Pappu and her colleagues are true Levallois points.

“It’s still basically a single point in a giant continent,” she added — more discoveries are required to give context to this find.

That’s what Pappu hopes for, too. She noted that relatively few paleontology resources have been invested in India. The tools collected at Attirampakkam are among the first discoveries from India for which scientists even have a date.

“We hope this will be a jumping-off point for a new look at regions like India,” she said. “They also have a story to tell.”

Read more:

Oldest Homo sapiens fossils discovered in Morocco

Scientists discover the oldest human fossils outside Africa

Archaeology shocker: Study claims humans reached the Americas 130,000 years ago

The Oldest Human Fossil Outside of Africa Has Been Found

(THIS ARTICLE IS COURTESY OF TIME NEWS AND THE AP)

 

This undated photo provided by researcher Gerhard Weber shows a portion of the upper left jaw and teeth from the Misliya-1 fossil. Researchers found the jawbone in an Israeli cave, indicating that modern humans left Africa as much as 100,000 years earlier than previously thought. (Gerhard Weber/University of Vienna via AP)
This undated photo provided by researcher Gerhard Weber shows a portion of the upper left jaw and teeth from the Misliya-1 fossil. Researchers found the jawbone in an Israeli cave, indicating that modern humans left Africa as much as 100,000 years earlier than previously thought. (Gerhard Weber/University of Vienna via AP)
Gerhard Weber—University of Vienna/AP

By SETH BORENSTEIN / AP

January 25, 2018

(WASHINGTON) — A fossil found in Israel indicates modern humans may have left Africa as much as 100,000 years earlier than previously thought.

Scientists say that an ancient upper jawbone and associated stone tools could also mean that Homo sapiens — modern humans — arose in Africa far earlier than fossils now show. And it may cause rethinking about how we evolved and interacted with now-extinct cousin species, such as Neanderthals.

“When they start moving out of Africa and what geographical route they choose to do it are the two most important questions in recent human evolution,” said Tel Aviv University anthropologist Israel Hershkovitz, lead author of a study published in the journal Science .

The jawbone, complete with several well-preserved teeth, was found to be somewhere between 177,000 and 194,000 years old.

Previously, the oldest fossils of modern humans found outside of Africa were somewhere from 90,000 to 120,000 years old, also in Israel. So given the range in both those estimates, the jawbone might be about 50,000 to 100,000 years older.

The jaw was found in 2002 in the collapsed Misliya (miss-LEE-uh) cave on the western slope of Mount Carmel. Researchers spent the last decade-and-a-half looking for more remains and other fossils before publishing their study. They say the jaw belonged to a young adult of unknown gender.

The Science paper suggests modern humans could have left Africa 220,000 years ago, with some of the authors saying maybe it was even earlier. That’s in part because the cave also contained about 60,000 flint tools, mostly blades and sharp points, some of which are 250,000 years old, said study co-author Mina Weinstein-Evron.

“Now we have to write another story,” Weinstein-Evron said. “People were moving all the time.”

Scientists believe our species dispersed from Africa more than once.

The tool supply in the cave and other evidence were so complete it basically showed “industry” by the early modern humans, she said. “This guy or woman would have been very busy,” she said. “He didn’t have enough time do this. He couldn’t have made all of it. He must have had some friends.”

One of the interesting things about the tools is that while they were used on animal hides for meat and skin use, they were more frequently used on vegetables, Weinstein-Evron said.

Eric Delson, a paleoanthropologist at Lehman College and the American Museum of Natural History who wasn’t part of the study, said in an email, “Misliya may be one of several ‘out of Africa’ migrations” and even though it is the oldest modern human fossil, there may have been even earlier migrations.

He and others said the jawbone finding makes sense and is an exciting discovery.

Israel Hershkovitz, an anthropologist at the Tel Aviv University in Israel and the study’s lead author, said the ages of the jaw and the tools suggest our species had left Africa 200,000 years ago or earlier. And that, he said, suggests we may have appeared in Africa as long as 500,000 years ago. The oldest known fossils of our species are about 300,000 years old.

Weinstein-Evron and Hershkovitz insist those tools could only have been made by Homo sapiens.

But Delson and two other experts unconnected to the study disagreed, saying the tools may have been made by Neanderthals or another of our evolutionary cousins.

There is “very solid data” that Neanderthals used the same type of tool about 290,000 years ago in western Europe, and that species was around western Europe from 400,000 years ago until about 40,000 years ago, said Paola Villa of the University of Colorado Museum of Natural History.

SPONSORED FINANCIAL CONTENT

Poetry For Healing

Words from the Heart

Sun in Gemini

SteveTanham - writing, mysticism, photography, poetry, friends

HR'S wat's this plant?

A new series on interactive plant identification

ABDUL SHOP

We make buying easy!

On The Minds

Between the lines

Stella, oh, Stella

Garten - Reisen - Lesen - Musik - Handarbeiten - Motorbike no more! - Wandern ...

campogeno

die welt aus der sicht eines einsiedlers

roxy743

Learning Experience

Geek Mamas

A Parenting and Lifestyle Blog with a Dash of Geek

%d bloggers like this: