History Podcasts

Prehistoric Humans Cross the Atlantic

Prehistoric Humans Cross the Atlantic


Hieroglyphics of the Mi’kmaq

Written languages are almost nonexistent in Native American cultures to the extent that only a single written language is known to have existed in all of America and Canada. That single language belongs to the Mi’kmaq—a culture that lived along the Atlantic Coast—and it happens to share a bizarre number of similarities with Egyptian hieroglyphics.

A comparison of Egyptian and Mi’kmaq hieroglyphs. Credit: Barry Fell. (Author provided)

In the early 18th century, a French missionary by the name of Pierre Maillard meticulously documented the hieroglyphs of the Mi’kmaq culture during his time in the area. However, it wasn’t until the 1970’s that professor Barry Fell meticulously poured over the missionary’s work and published a comprehensive side-by-side of the Mi’kmaq writing with ancient Egyptian hieroglyphics. He’d found an astonishing number of similarities between the two forms, which led him to suggest that the Egyptians must have reached the Atlantic Coast at some point in the past: as that seemed more reasonable than simply dismissing it all as a staggering coincidence.

Viewing the research, academics agreed that the similarities were too great for it all to simply be a coincidence. However, with isolationism still in full swing, the idea of Egyptians reaching America was written off as nonsensical. Instead, an alternative explanation was devised: the French missionary must have made it all up. This new theory, being the only explanation that fits conventional history, posits that Maillard devised the entire system of writing in order for the Mi’kmaq to be able to record the teachings of Christianity.

Why he would use hieroglyphics—the writing of a pagan culture—instead of his own native writing is baffling. Yet the theory becomes even more absurd when one remembers that hieroglyphics weren’t translated until the next century. So how did he manage to match so many of the symbols and concepts?

Further examples of similar Egyptian and Mi’kmaq hieroglyphs. Credit: Barry Fell. (Author provided)

Top image: San Lorenzo Colossal Head 1, Olmec culture, Museo de Antropología de Xalapa , Mexico. ( CC BY-SA 3.0 )


Prehistoric Humans Cross the Atlantic - HISTORY

(CNN) -- It's a discovery that could rewrite the story of southeastern United States. Stone tools and mastodon bones found at the bottom of a Florida river point to humans living in the region 14,550 years ago. That's more than 1,500 years earlier than previously believed, scientists say.

"This is a big deal," said Jessi Halligan, one of the study's authors and an assistant professor of anthropology at Florida State University.

"It's pretty exciting. We thought we knew the answers to how and when we got here, but now the story is changing." The discovery on the Aucilla River was reported Friday by the journal Science Advances. Here are some of the details:

Butchered bones, knives

The four-year study included sending divers to the Page-Ladson site, a deep hole 30 feet underwater in the Aucilla River, researchers said. There, divers excavated artifacts such as butchered bones of extinct animals, a mastodon tusk and a biface, which is a knife fragment with sharp edges.

 Divers excavated bones and tools from the Page-Ladson, which is 30 feet underwater in the Aucilla River. "At Page-Ladson, hunter-gatherers, possibly accompanied by dogs, butchered or scavenged a mastodon carcass at the sinkhole's edge next to a small pond at around 14,550 years ago," the authors said in Science Advances.

What was once a pond was buried beneath the murky waters for a series of reasons, including centuries of civilization, rising sea levels and layers of sediment. "These people had successfully adapted to their environment they knew where to find freshwater, game, plants, raw materials for making tools, and other critical resources for survival." The scientists used radiocarbon dating techniques to find out how old the artifacts are.

Aaaah! What about the Clovis?

Until that point, researchers had believed the Clovis people were among the first inhabitants of the Americas about 13,000 years ago, according to the study. Page-Ladson is the first pre-Clovis site documented in the southeastern part of North America, it said. "The new discoveries at Page-Ladson show that people were living in the Gulf Coast area much earlier than believed," said Michael R. Waters, director of Texas A&M's center for the study of the first Americans. Waters was one of the study's lead authors.

In the 1980s, other researchers had retrieved several stone tools and a mastodon tusk from the site, but their discovery did not make much news. Halligan and her colleagues returned to the site in 2012 and expanded on the previous research and archaeological finds. In one of the instances, a mastodon tusk recovered earlier had deep grooves. They concluded the grooves were made by humans during the tusk's extraction.

Now. more discoveries that have been suppressed because of politicizing the "Native Americans came from Asia" theory. Enter -- the European SOLUTREANS!

Scallop fishermen net historic artifacts

Tasty deep-sea scallops like to burrow deep in the ocean floor. Fishermen plow and trawl the sea bottom far off shore, pulling up thousands of scallops at a time in their nets. Sometimes they also find other things.

In 1971 a scallop boat, the Cinmar, was fishing 60 miles east of the Virginia cape, in 240 feet of water when they pulled up part of the jaw from an ancient mastodon -- a large extinct elephant from the last ice age. Along with this catch they also found a curious stone spear point that resembled the famous Clovis points from 13,000 years ago.

The area where these artefacts were found was once dry land. During the last ice age the oceans of the world were much lower. Much of their water was locked up in huge glaciers that covered the Northern latitudes. The bones and spear were likely remnants of pre-historic hunting by some of the earliest inhabitants of North America. But there were even more surprises to come.

Carbon dating of the mastodon bone indicated it was 22,760 years old. Researchers also scrutinized the blade. It had not been smoothed by wave action or tumbling. They concluded the blade had not been pushed out to sea but had been buried where the Cinmar found it.

Chemical analysis of the spear point showed that it originated from flint in an area that is now France! Analysis of the way it was made showed that it was not a Clovis point at all, but a hand crafted point made by European humans known as the Solutreans.

The first humans entered North America from Western Europe -- not Asia

[Above:] The coastline of the continents was very different at the height of the last ice age. It was then that mysterious Stone Age European people known as the Solutreans paddled along an ice cap jutting into the North Atlantic. They lived like Inuits, harvesting seals and seabirds.

Most archaeological evidence of the Solutreans indicates they originated in what is now Spain, Portugal and southern France [ A ] beginning about 25,000 years ago. No skeletons have been found, so no DNA is available to study.

The Solutreans had a distinctive way of making their stone blades and this same skill and technology has been found in numerous archaeological sites along the East coast of North America [ B and C ].

Stone tools recovered from two other mid-Atlantic sites -- Cactus Hills, Va., 45 miles south of Richmond, and Meadowcroft Rockshelter, in southern Pennsylvania -- date to at least 16,000 years ago. Those tools also strongly resemble Solutrean blades found in Europe.

The Solutreans eventually spread across North America, carrying their distinctive blades with them and giving birth to the later Clovis culture, which emerged some 13,000 years ago. Clovis gets its name from Clovis, New Mexico, where the first such blade was discovered.

Old Paradigms Die Slowly

Until very recently the dominant theory of human migration to North America had Asians crossing the Bering Straits [ F ] to Alaska and coming through a narrow ice free corridor [ E ] that allowed access to the Central Plains. This was supposed to have happened around 15,000 years ago. A major archaeological site used to support the Asian "first" migration was the Dyuktai culture in Ushki, Siberia however this site has recently been re-dated to a much younger 10,000 years old. Despite the much older dates of the Solutreans in eastern North America, many anthropologists continue to cling to the Beringia idea.

It is inevitable that these old ideas will give way to the Solutrean hypothesis. I'll give some of the reasons in this article, including some new discoveries in Nevada [ D ] and also:

  • Evidence of knapping (stone tool making) techniques
  • Evidence of DNA markers
  • Evidence of ice flow data
  • Evidence of cultural data

I think you will see that it is time to rewrite history and give credit to the Solutreans, not only for the Clovis Culture, but for the paleo-Indians of North America.

Evidence of stone tool techniques

Despite the best efforts of archaeologists and other researchers, the Siberian archaeological record has yet to yield compelling evidence to link the first American settlers with Siberia. One of the ways to establish such a link would be to find evidence in Siberia of the Clovis points that are found at most early American sites.

Excavation at the Dyuktai Cave site in north eastern Siberia revealed an assemblage that included stone spear points similar to Clovis points [ A ], as well as small stone tools known as microblades [ D ], and the remains of large mammoth and musk-ox. A series of similar sites were later found in the region, and some archaeologists have suggested that it was the people of the Dyuktai culture who crossed the Bering Land Bridge and settled the Americas.

Another difference in Asian v. European blades in that both Solutrean and Clovis are bi-facial, meaning that each side was completely flaked. In Asian blades the flute (i.e. a flaked or thinned zone at the base to accommodate fastening to a shaft) is absent and usually flaked more on one side than the other. Although the flute is dramatic on Clovis points, Solutrean points have a more subtle thinning at the base.

Although both the Dyuktai and Clovis sites exhibit evidence of big-game hunting, there are significant differences between them. For example, the Dyuktai points do not display the characteristic Clovis "flute" [ B ] . In addition, the microblade tools (i.e. several sharp pieces of stone were placed in grooved bone) which are common at the Dyuktai sites are not found at early archaeological sites in the Americas. Also, as we stated earlier, the Dyuktai site is much younger than Clovis.

Like cutting diamonds

Stone tools may seem primitive in today's world but, before the invention of metallurgy and electricity, these artifacts were the hi-tech of their time. Using these sharp instruments for hunting and cutting was vital to human survival. The designs had to evolve to be reliable and highly efficient. Once a particular design or production technique was perfected it was duplicated by the artisans and tool makers of that particular culture.

Archaeologists and anthropologists have spent years examining the stone knives and spear points of various ancient cultures. They have looked at every detail -- every step -- involved in shaping a rough stone to a streamlined spear point. Many, like Dennis Stanford and Bruce Bradley [1], have even attempted to duplicate the production of stone points from sites around the globe.

Finding the right type of stone is critical. Flint, quartz and jasper were prized for their strength and flaking abilities. Various techniques were used to remove flakes and shape the stones. Sometimes the stone was struck with another stone and other times the technique called for a softer implement such as an antler bone and just the right pressure to carefully crack and remove flakes from the surface or edge of a stone point.

By understanding the various techniques used by different cultures they determined that the Clovis and older Solutreans had developed something special -- called "over flaking" -- where a large flake was removed laterally across the point instead of many smaller flakes. This was a dangerous technique if not done with a high degree of skill. One wrong move, or too much pressure, and the knife or spear point would be ruined.

It is this skill that they saw exhibited by the Solutreans, and later the Clovis culture, that convinced them of an ancestral link. No such technique appears in stone points from Siberia.

Once you make the connection between Clovis artifacts and the Solutreans, the distribution of Clovis in the East makes perfect sense. The origin of earliest inhabitants of North america did not come from the Northwest -- they came from Europe by way of the North Atlantic ice sheet and moved West across the continent.

The map [above] also suggests that they preferred to live near rivers, perhaps the preferential habitation of game. The map also suggests that the Clovis migration took them North through the ice-free corridor, although only a few artifacts have been found there.

Some die-hard archaeologists have denied the eastern origins of Clovis, claiming that they originated in the West, migrated South to Central America where they crossed over to the East coast and moved North. This complicated migration is used to explain the multitude of Clovis artifacts found in the East. Their evidence for this is a recent find of Clovis points in Alaska. But critics point out that the dates of these points are about 12,000 years ago -- well after the arrival of Clovis in the western continent. [source]

It is important to remember that the proponents of the Clovis/Solutrean hypothesis do not deny that a prior substantial migration to the Americas from Asia took place. It is possible that the continent was inhabited by humans tens of thousands of years before either group was in North America. What we are discussing here is the migration of a culture with historic traits such as tool making, hunting patterns and presumably a common language and social organization. We can only discover this kind of unique population if consistent evidence of these cultural traits is found.

Most certainly, migrations from Asia did eventually overcome those of the Solutreans and subsequent Clovis culture. Stone tool development changed as mastodons were replaced by smaller game. Rival tribes may have annihilated each other, as we have seen such violence in the Kennewick Man's remains. [source]

Intentionally buried time capsules

Most of the finds involving caches of Clovis artifacts were intentionally buried with the blades carefully stacked together and placed in a vertical alignment to avoid being crushed. The reason for these burials is unclear but may have been for safe keeping and re-use by hunters when their supply of blades or the stones to make them became scarce.

Also, archaeologists have found giant Clovis blades that are too big for hunting and appear more ornamental than utilitarian. Were these enlarged teaching tools to help future artisans? Or perhaps they had some religious or totem significance? We just do not know.

Besides stone blades, hooks and sewing needles made from bone have been found at some sites. It is thought that the Solutreans and later Clovis cultures must have been adept at making warm and durable clothing from animal skins to survive the cold climates.

This introduces another interesting hypothesis. The Inuit in alaska make sea worthy boats from animal skins. It is certainly possible that the Solutreans, having mastered the sewing of animal skins, could have done the same thousands of years earlier.

NEXT -- DNA Evidence linking American Indians to Europeans

Notes:
[1] Dennis J. Stanford and Bruce A. Bradley, ACROSS ATLANTIC ICE: The Origin of America's Clovis Culture, University of California Press, 2012, ISBN 978-0-520-22783-5 (available from amazon.com)

Little did Domingo "Buzzy" Ybargoitia know that by drilling a well to bring water to his sheep, he would change the way we view the history of humans in the New World.

"My girls need to drink, that's all I was thinking about. It gets mighty dry around here come late summer anymore. I don't know what's going on, but I do know my granpoppa never had any trouble keeping his flock watered, and my pop didn't either. But I've had to truck it in from Marsing when it gets really hot."

Ybargoitia manages his family's sheep operation in Idaho's lonely Owyhee Mountains, an hour's drive over rough roads from the tiny Oregon village of Jordan Valley. Two years ago this coming April, he brought a drilling contractor from Nampa to install a dependable well. It was tough drilling until they got through the dense lime deposits, or caliche, that underlies so much of this remote southwest corner of Idaho.

"A couple of times, I was afraid those boys were going to give up," says Ybargoitia. "They'd pull their bit out of the shaft and just shake their heads when they saw how chunked up it was getting."

On the second morning of drilling, they unearthed an astonishing surprise. The hole was below the caliche, down to about 26 feet, when Ted Burquart of the drill crew pulled what looked to be a child's doll from the mud and sand accumulating next to the hole.

"At first, I just thought it was just one of those Troll dolls you see hanging from rearview mirrors," explained Burquart. "I wiped the crud off and took a better look at it. It was whittled out of rock, I could tell that much. And what I thought was crazy Troll hair all flattened out was really a funny little cap. Like a beret, maybe."

Ybargoitia knew immediately what it was. As a youth, he had spent too many years with the Oinkari folk dancers of Boise to not recognize a traditional Basque txapela, even if it was small enough to top a five-inch figure. He stopped the drilling and sifted through the pilings with his fingers, wondering what else might have been brought up. Within minutes, he had found several blades, chipped to a razor's edge on both sides, ranging from 9 to 20 centimeters long. Each one had a notch into which a spear shaft could be set. He also found a small, partially eaten and mummified sheep thigh, impaled on a nearly petrified willow skewer.

"Back then, I didn't know a Clovis point from a Buck knife, but I sure as heck know a lamb kebab when I see one."

He was also relatively certain that all of these items -- particularly the primitive figurine -- were highly unusual coming from so far below the surface. Ybargoitia sent the drill crew home, gathered up everything he'd found into his lunch box, and called the Treasure Valley Community College in Ontario, Oregon. He was referred to the Cultural Anthropology Department.

"When Buzzy showed me those things, I about fell out of my chair," said Dr. Benton Schrall, the department head. "North American artifacts aren't exactly my field. Still, I recognized immediately that he had stumbled onto something very significant."

That afternoon, Dr. Schrall e-mailed a colleague at Washington State University in Pullman, who put him in touch with Dr. Lawrence Riggs, the chairman of WSU's Archaeology Department. Said Dr. Schrall, "When I described to Larry what I had, right there on my desk, the first thing out of his mouth was, 'Whatever you do, don't tell any Indians about it!' I guess he got burned pretty bad on that Kennewick Man deal."

With two of his brightest grad students in tow, Dr. Riggs drove to Ontario the next day. As soon as he saw the artifacts, he knew exactly what he would be doing for the next several summers. "Clovis points in Idaho? And from 7 meters down! That alone is an archaeologist's dream, without even considering the totem figure."

Fearful of letting that figurine out of his sight, Dr. Riggs shaved a thin specimen from the bottom of one tiny foot and sent it to Le Duchamp Laboratoire in Lyons, France, a world leader in intra-spectral comparative analysis. He then spent the next six weeks organizing what would become the largest -- and most covert -- archaeological dig in Idaho's history. Even Ybargoitia was sworn to secrecy.

"Larry Riggs had me sign a paper that said as long as I didn't tell anyone else about what I'd found, his university would foot the bill for another well. He came down on spring break, along with a nine-seater van full of students, and they set up a cyclone fence around that spot and put a tent over the hole. It about killed me that I couldn't tell anybody. It was like getting to be in a movie or something, only I couldn't even let my friends know I was in it."

The excavation proper began after the semester ended on May 21, 2005, and by Labor Day of that year, Dr. Riggs had confirmed what his instincts had been telling him since he first saw the figurine. Le Duchamp lab sent him their analysis of the sample in early July. They had tested the specimen three times, and for further confirmation, they had sent a portion to another independent laboratory in Quebec to verify their findings. There could be no mistake: The sample was from a unique soapstone found only in a region of northern Spain, on the southern slopes of the Pyrenees Mountains.

It took 10 weeks of excruciatingly detailed soil removal for the team to get down as far as the drill bit had reached, but at a depth of just under 8 meters -- the investigators came across a strata of soot and charcoal, indicating the remains of an ancient campfire. Within a 5-meter radius of that fire pit, they uncovered a dozen more spear tips -- sophisticated Clovis points, all of them -- the gnawed bones of several seemingly domestic sheep, a shredded remnant of what appeared to be a leather drinking sack (a bota), and a human skull.

By summer's end, Dr. Riggs had circumstantial evidence that early humans had migrated to this hemisphere from the Iberian Peninsula. But most astounding was the level at which this body of evidence had been found. The geological strata in which the items lay dated from a very narrow (and little understood) time frame known as the Proto-Paleolithic, indicating that human beings had put their footprint on the New World 40,000 years before anyone had previously believed possible.

Even more momentous were the "associative implicatory collateral traces," as they are called in the field of paleoanthropology, which implied that wherever these people came from, they brought their sheep with them.


  • Researchers suggest early humans left Africa in small groups 120,000 years ago
  • These early movements were followed by a large wave around 60,000 years ago
  • Our ancestors interbred with Neanderthals and other human-like species
  • Researchers came to their conclusions as part of a review of recent research into human migration across Asia

Published: 19:00 BST, 7 December 2017 | Updated: 14:49 BST, 8 December 2017

The date the first humans migrated from Africa has been pushed back 60,000 years by scientists.

Researchers suggest that early humans began crossing to Eurasia as early as 120,000 years ago.

The traditional 'Out of Africa' model suggests that modern humans evolved in Africa and then left in a single wave around 60,000 years ago.

But advances in DNA testing and other fossil analysis techniques show that humans actually arrived in Asia much earlier than previously thought, according to a review of recent research.

The study also claims migrants dispersed across Eurasia in a number of waves across tens of thousands of years, interbreeding with their human-like cousins along the way.

Researchers suggest that early humans began crossing to Eurasia as early as 120,000 years ago. Pictured is a map of sites and migratory pathways taken by modern humans dispersing across Asia according to findings from a new study

WHEN DID HUMANS LEAVE AFRICA?

The researchers reviewed a flood of new early human discoveries reported from Asia over the past ten years.

Homo sapiens reached distant parts of the Asian continent, as well as Near Oceania, much earlier than previously thought, recent findings show.

For example, H. sapiens remains have been found at multiple sites in southern and central China that have been dated to between 70,000 and 120,000 years ago.

Based on these studies, humans could not have come in a single wave from Africa 60,000 years ago, the study found.

Instead, multiple, smaller movements of humans out of Africa beginning 120,000 years ago were then followed by a major migration 60,000 years ago.

The researchers, from the Max Planck Institute for the Science of Human History in Jena, Germany, reviewed research on early human migration spanning the past decade.

Recent findings show that the 'Out of Africa' theory does not tell the full story of our ancestors, the study found.

Instead, multiple, smaller movements of humans out of Africa beginning 120,000 years ago were then followed by a major migration 60,000 years ago.

Most of our DNA is made up of this latter group, but the earlier migrations, also known as 'dispersals', are still evident.

This explains recent studies finding that all modern non-African populations branched off from a single group in Africa around 60,000 years ago.

'The initial dispersals out of Africa prior to 60,000 years ago were likely by small groups of foragers, and at least some of these early dispersals left low-level genetic traces in modern human populations,' study coauthor Professor Michael Petraglia said.


Crossing the Atlantic: Then and Now

Students use a map to compare and contrast transatlantic travel during colonial times and today, including changes in travel time and comfort.

Geography, Human Geography, Physical Geography

1. Introduce the concepts of ocean travel and ocean crossings.
Ask: Why might people want to travel all the way across the ocean? Elicit student responses, such as to visit family and friends to explore new sites on vacation to trade goods and to move or resettle. List them on the board. Encourage students to think about why people would want to move from one side of the ocean to the other and resettle. Ask students to imagine that they will be taking a trip across the Atlantic Ocean. Ask: What type of transportation might you take to cross the ocean? (plane, boat)

2. Discuss the differences between ocean crossings hundreds of years ago and today.

Explain to students that hundreds of years ago people often crossed the Atlantic Ocean to explore new places and move from one place to another. They traveled on sailing ships. Tell students that people traveling from Europe to North America during the colonial period of 1600-1799 faced a long, dangerous journey. They often became sick and even died while making the crossing. Ask: Why is making the same journey today much faster and easier? Elicit from students that ships no longer rely on wind and that airplanes are now the fastest way to make the same journey.

3. Distribute copies of the worksheet Crossing the Atlantic.
Ask students if they know what the large body of water is in the center of the map. Then read aloud its label: Atlantic Ocean. Point out that the landmass on the right (east) side of the map is the continent of Europe, and the land on the left (west) is North America. Ask students to point out where they live on this map. Next, point out Amsterdam on the map. Explain to students that this is a city in Europe where many planes and boats leave to travel across the ocean—both today and during the colonial period. Point out New York City on the map. Explain that this is a popular destination for planes and boats traveling across the Atlantic Ocean. Encourage students to use a ruler and the scale bar on the map to measure the distance between Amsterdam and New York City. Finally, point out the icons on the map that depict three different forms of transportation used to travel across the Atlantic Ocean. Tell students that the plane and modern ship are used for ocean crossings today, and the sailing ship was a popular form of transportation for crossing the ocean hundreds of years ago. Explain that students will use the map to compare journeys made on a colonial ship, a modern ship, and an airplane.

4. Compare the time needed to cross the Atlantic Ocean by ship and airplane.

Ask students to estimate how long it might take to sail a ship across the Atlantic Ocean. Ask: Would it take an hour, a day, a week, or longer? Tell students that Henry Hudson was a European explorer traveling across the Atlantic during the colonial period. It took Hudson more than two months to sail from Amsterdam to New York City on his sailing ship, the Half Moon. A modern ocean liner, such as the Queen Mary 2, makes the trip from Europe in seven days. By plane, the trip is less than an 8-hour flight. Look at a calendar and mark the number of weeks, days, and hours for each trip, using a different colored marker for each increment of time. Help students write the length of time for each mode of transportation on their worksheets. Then pick a departure date and have students count how many days the voyage will take for each of the different transportation modes. Have students add this number to their maps.

5. Have a whole-class discussion about crossing the Atlantic, then and now.
Have a whole-class discussion. Ask:

  • If the two boats and the plane were in a race, which would win? Which would come in second? Which would finish last? Have students number each of the three modes of transportation on their worksheets with 1 being the fastest and 3 the slowest. (1-plane 2-modern ocean liner 3-sailing ship)
  • How was the Half Moon powered? (Wind filled the sails, which moved the ship across the ocean.)
  • What might happen if there was no wind? (The ship would slow down or even stop.)
  • Why do modern ships travel much faster than colonial ones? (Modern ships have powerful engines that help them move much faster they don't rely on wind.)
  • Why are planes able to cross the ocean so quickly? (They travel much faster through the air than ships travel on water.)

Informal Assessment

Ask students to think about what they learned and orally state things that affect how long a journey across the ocean might take. Students' ideas should include, in their own words, the distance that must be traveled, the type of transport, how a vessel is powered, the weather, and how modern the method of transport is.

Extending the Learning

Ask students to imagine that they need to pack for a journey across the Atlantic Ocean. They may travel by colonial sailing ship, modern ship, or plane. Have them draw a picture of the items they would need to bring for each type of trip. Have students share their drawings and compare items that would be needed for each of the modes of transportation.


Was Hominin Interbreeding Common?

The new study suggests that past interbreeding may have been much more common than once thought. Only a handful of these ancient hominins have been sequenced, and already scientists have found a first generation offspring, Slon says, calling the odds “quite striking.”

It's possible this is sampling bias, notes Green. Caves tend to preserve bones well, and perhaps they're just the place where diverse groups came together. “They're the singles bars of the Pleistocene Eurasia,” he quips.

But the more we look, it seems, the more interbreeding we find: The Denisovan father of this teenager also shows traces of Neanderthal relatives. And in 2015, researchers announced the discovery of a human mandible from a cave in Romania that had Neanderthal ancestors as recently as four to six generations back.

The new find is giving us a peek into an ancient world in which breeding happened freely between hominins from all walks of life, Reich says. “That sort of qualitatively transforms and changes our understanding of the world,” he says. “And that's really exciting.”


A Global History of Sitting Down

Here I was, interviewing the architect Witold Rybczynski about his new book, an appreciation of the chair and its 5,000-year history, and I was doing it from a standing desk. Nearby, I had a perfectly tolerable chair, with snazzy features like a mesh-fabric seat, pneumatic seat-height adjustment, and polyurethane armrests. But it wasn’t looking so appealing, perhaps because the American Heart Association had just ruined chairs for me by advising people to sit less and move more, so as to avoid diabetes and cardiovascular disease. I asked Rybczynski if he felt the chair was unfairly maligned in the Age of Standing Desks and Office Exercise Balls.

“I really don’t think we’re in the age of the standing desk,” Rybczynski responded. “I think it’s a fad which will come and go. People have always worked standing up—Winston Churchill, Ernest Hemingway.” (Treadmill desks, in Rybczynski’s book, are summarily dismissed as “silly.”) Today’s health warnings, he added, are about breaking up lengthy periods of sitting with movement, not about chairs themselves.

Rybczynski decided to write about the chair in part because it uniquely combines fashion and functionality. He was also struck by the fact that, unlike weaponry or communications technology, chairs don’t necessarily get “better” over time. “If you’re sitting in a Windsor chair, that’s the same chair, for all practical purposes, that George Washington and Benjamin Franklin sat in,” he said. “Nothing else from that time, other than the [U.S.] Constitution, has survived [in such usable form].” The history of the chair, in other words, is less evolutionary than it is cultural. “The way we choose to sit, and what we choose to sit on, says a lot about us: our values, our tastes, the things we hold dear,” Rybczynski writes in his book, Now I Sit Me Down. You are how you sit.


Human evolution was shaped by interbreeding

If your ancestors hail from anywhere outside Africa, it's a safe bet that you are part-Neanderthal.

After modern humans first left Africa, they came into contact with Neanderthals and things got cosy. These early frolics are now visible in our DNA. Genetic analysis indicates that Europeans and Asians obtained 1-4% of their DNA from Neanderthals.

It seems everyone was at it. Neanderthals interbred with another species, the Denisovans, as did some of us. Some people from South East Asia have up to 6% Denisovan DNA.

Even Africans whose ancestors never left the continent carry some Neanderthal DNA, because 3,000 years ago people from Europe and Asia migrated to Africa. Many modern Africans have inherited some genes, including some Neanderthal ones, from these people.

Now some scientists are going even further. They propose that our entire species is the product of hybridisation between species, and that we owe much of our success to this very fact.

You might not like this idea, in which case it's worth bearing in mind that hybridisation is common in nature.

The "Oase individual" inherited between 6% and 9% of his DNA from the Neanderthals

Brown bears and polar bears can successfully interbreed when they meet. Most of the Galápagos finches are the result of interbreeding, as are many primate species like baboons and gibbons.

"Seven to 10% of all primate species hybridise, which is common considering a lot don't ever come into contact with each other," says Rebecca Ackermann of the University of Cape Town in South Africa.

In July 2015 it emerged that a hybrid coral is doing better than either of its parent species. It can survive in a busy shipping channel, which its parents cannot do.

In the past five years, evidence of separate interbreeding events between modern humans (Homo sapiens) and our early ancestors has increased.

In June 2015, researchers announced that a 40,000-year-old skeleton from Romania had the most Neanderthal DNA of any human analysed to date. The "Oase individual" inherited between 6% and 9% of his DNA from the Neanderthals.

Furthermore, the team found that his Neanderthal ancestor lived only 200 years before his death. The genetic evidence confirmed something that anatomists had previously suggested: the Oase individual's jawbone had some clear Neanderthal traits.

If these new traits are useful, they can be passed onto future generations

Intriguingly, the Oase individual did not pass on his Neanderthal genes to modern-day Europeans. Clearly, someone else did, because their DNA is still present.

The Oase individual is just one instance of interbreeding, and more will surely be found as researchers analyse ever more ancient DNA.

Writing in the journal Evolutionary Biology, Ackermann and colleagues argue that hybridisation has worked in tandem with other evolutionary processes "that act to diversify populations".

Hybridisation can also result in new combinations of traits, says Ackermann. "It can be quite a creative evolutionary force, which is not how people thought in the past. Brand-new things could be the product of hybridisation."

Ackermann studies hybrid mice and has found that hybrid lineages often have anomalies in their teeth. There was also a great deal in variation of their size. If these new traits are useful, they can be passed onto future generations.

Of course, beneficial traits can also arise through chance mutations. But if we had to wait for such events we might be waiting for a long time.

The ones that survived were products of mating between Europeans and North Americans

Interbreeding can speed up these changes, says evolutionary geneticist Rasmus Nielsen of the University of California, Berkeley in the US. When modern humans left Africa, integrating with other species therefore allowed us to adapt to new environments much more quickly.

For example, the DNA evidence hints that we inherited the ability to fight certain diseases from Neanderthals. When we first arrived in Europe our immune response may have struggled to deal with unfamiliar local diseases, but the offspring of those that interbred with Neanderthals fared better.

The same occurred when Europeans began colonising the Americas, bringing diseases that proved catastrophic to the indigenous population. "The ones that survived were products of mating between Europeans and North Americans," says Nielsen. "Something similar happened, but maybe on a grander scale, between Neanderthals and modern humans."

There is one problem with the idea that hybridisation has been crucial for our evolution. We do not have evidence of any interbreeding between species before modern humans left Africa.

That means some modern humans are known to be hybrids, but not all. Furthermore the known hybridisation events all happened relatively recently, when our species had already evolved to be more-or-less the way it is today.

Of all the many human species that have evolved, only ours has survived to the present day

There is a simple reason why we do not have hard evidence of ancient interbreeding in Africa: we have not yet been able to analyse any DNA that ancient.

However, some researchers believe it did happen. A 2011 study found that some groups of Africans carry genetic material from "an archaic population that split from the ancestors of modern humans". The results are hard to explain without hybridisation, says Nielsen, who was not involved in the study.

Ackermann agrees. There were many species of early human-like creatures, often living alongside each other, one of which eventually gave rise to us. We don't know who or when, but it seems reasonable to expect that these long-lost species had the occasional romp.

If Nielsen and Ackerman are right, it means we are all hybrids to some extent.

Ackerman goes further, and argues that we owe our cultural success to these ancient meetings.

Of all the many human species that have evolved, only ours has survived to the present day. Our complex culture has clearly been a big part of our ability to outcompete the other species.

We have very little in the way of theory about how human cultural interactions and institutions may have evolved

Mixing with other species could have helped us develop that culture. When our ancestors met other species, they may have shared knowledge as well as genes.

Learning new habits and tricks from other species could have helped spur on our development. "The things we think of as creativity could be as the result of interaction between different groups," says Ackermann.

We had clearly evolved to be good at copying, learning and innovation, says Simon Underdown of Oxford Brookes University in the UK. These are traits that primed us to become the cultural beings we are today.

Not everyone is convinced that hybridisation has played a key role in this process.

We might be able to a sequence DNA from much older human specimens

We produced many of our greatest innovations in the past 10,000 years, says Francesco D'Errico of the University of Bordeaux in France. Throughout that period, we were the only human species around. "This implies that innovations emerged in human history for reasons other than from hybridisation."

"We have very little in the way of theory about how human cultural interactions and institutions may have evolved," says Aaron Stutz of Emory University in Atlanta, Georgia, US. So it's hard to draw any firm conclusions about the role of interbreeding.

The answer may come from genetics.

One day, possibly within a few years, we might be able to a sequence DNA from much older human specimens. Only then it will become clear just how much hybridisation has shaped who we are.

Melissa Hogenboom is BBC Earth's feature writer. She is @melissasuzanneh on Twitter.


Finding Ways

As scientists debate the peopling of the Americas, it’s worth noting there could be more than one right answer. “I think current evidence indicates multiple migrations, multiple routes, multiple time periods,” says Torben Rick, an anthropologist at Smithsonian’s National Museum of Natural History.

Rick began his own career studying a likely migration along the “Kelp Highway”—the rim of coastline that apparently once stretched from Asia all the way around to North America.

“People could basically stair-step their way around the coast and have a similar suite of resources that they were in general familiar with,” says Rick, who has spent years excavating sites on the California coast. Rick’s late Smithsonian colleague Dennis Stanford famously advocated the Solutrean hypothesis, which claims the first Americans came over from Europe, crossing the ice of the North Atlantic. Rick isn’t sold on the idea, but he praises Stanford’s willingness to explore an unusual notion: “If we don’t look and we don’t test it and don’t rigorously go after it, we’ll never know for sure.”

Regarding sites in South America that date back more than 14,000 years, could humans have traveled there by boat, perhaps from Oceania? It’s a question
researchers have had to consider. But, Rick says, the theory “doesn’t pass the smell test” because it’s unlikely that people then were capable of crossing an open ocean.

Still, he notes that scientists don’t know much about prehistoric watercraft because they were made of perishable materials. “We can say, ‘Ha-ha, that idea doesn’t work’—but I can’t tell you exactly why those early sites are there,” he admits. “Human ingenuity is incredible. I would never underestimate it.”


In a Few Centuries, Cows Could Be the Largest Land Animals Left

Throughout our entire history, humans and other hominins have selectively killed off the largest mammals.

There used to be a type of elephant called Palaeoloxodon that could have rested its chin on the head of a modern African elephant. There was a hornless rhino called Paraceratherium, which was at least 10 times heavier than living rhinos. There was once a giant wombat that could have looked you level in the eye, a ground sloth the size of an elephant, a short-faced bear that would have loomed over a grizzly, and car-sized armadillos with maces on their tails. After most of the dinosaurs went extinct at the end of the Cretaceous period, 66 million years ago, mammals took over as the largest creatures on land—and they became really big.

But during the late Pleistocene, from around 125,000 years ago, these megafauna started disappearing. Today, they’re all gone. The reasons for their extinctions have been thoroughly studied and intensely debated, but a new study by Felisa Smith from the University of New Mexico puts the blame squarely on humans and our hominin relatives.

By looking at how mammals have changed in size over time, Smith and her colleagues have shown that whenever humans are around, the mammals that disappear tend to be 100 to 1000 times bigger than those that survive. This isn’t entirely new: Many scientists, Smith included, have found the same trends in Australia and the Americas. But the new analysis shows that this pattern occurred in every continent except Antarctica, and throughout at least the last 125,000 years.

“Size-selective extinction is a hallmark of human activity,” Smith says. In other words, when we’re around, big animals die.

“It doesn’t take a lot to make a species go extinct,” says Advait Jukar from George Mason University. “Humans didn’t need to go out and kill every last individual all you need is a stressed population and just enough hunting pressure to keep the fertility rate [below replacement levels]. Eventually, the population will collapse.”

The distribution of body size is generally related to the size of a land mass. Africa is smaller than Eurasia but bigger than the Americas, so you’d expect its animals to weigh in somewhere in the middle. But by the time hominins left Africa, the average mammals there were about 50 percent smaller than the average ones in either Eurasia or the Americas. For that reason, Smith thinks these size-specific collapses started well before the rise of Homo sapiens, and probably dates back to the origins of Homo erectus, roughly 1.8 million years ago. That was the species that marked the shift from hominins that depend heavily on plants to ones that depend more on meat,” says Smith. “Being a good predator is a general feature of our genus.”

When hominins like Neanderthals, Denisovans, and modern humans spread through Europe and Asia, the average mass of mammals there halved. When Homo sapiens later entered Australia, the mammals there became 10 times smaller on average. And when they finally entered the Americas, with effective long-range weapons in hand, they downsized the mammals there to an even steeper degree. By around 15,000 years ago, the average mass of North America’s mammals had fallen from 216 pounds to just 17.

This is not a general feature of mammal evolution. Smith’s colleague, Kathleen Lyons from the University of Nebraska-Lincoln, has been collecting data on mammalian body size over the last 65 million years. Her data show that the biggest beasts only became disproportionately vulnerable to extinction in the last few million. “People make this assumption that large animals are more at risk,” says Smith. “But large animals also have larger geographic ranges, which buffers them against extinction. For most animals across most time, being large was a good thing.”

Even during huge changes in climate, including several ice ages and warm spells, large mammals weren’t especially vulnerable. To her, that should settle the long-running and often acrimonious debate about whether humans were actually responsible for the loss of the megafauna. “When it got warmer or colder, it didn’t select for bigger or smaller mammals,” says Smith. “It’s only when humans got involved that being large enhanced your extinction risk.”

But “it’s not a slam dunk that humans are responsible for the entire [megafaunal] extinction,” says Jessica Theodor from the University of Calgary. As other studies have shown, it can be hard to parse out the effects of human hunting, climate change, and the big changes that ecosystems undergo when big mammals start to disappear. All of these things often occurred simultaneously, and compounded each other. Still, as Kaitlin Maguire from the Orma J. Smith Museum of Natural History puts it, “while it’s thought that the megafaunal extinctions were a result of a one-two punch from shifting climate and human influences, this work demonstrates that the human punch was strong.”

Even if climate change wasn’t primarily responsible for killing off large mammals in the past, three things are very different now: The climate is changing at an extraordinary rate that change is now our doing and humans have shrunk the space available to wild animals. It used to be that large mammals could cope with rising temperatures or shifting rainfall by moving. Now, cities, farmland, and roads are in the way.

These changes mean that modern humans have also become adept at killing medium-sized and smaller mammals, weakening the size-specific trends that held for tens of thousands of years. Our ancestors killed mammals by hunting them. Now, we can indirectly usher them into extinction by shrinking their habitats or introducing unfamiliar predators.


Watch the video: Αγώνας κυριαρχίας- Ντοκιμαντέρ Greek Μέρος 12 (December 2021).