Stone Age Skull Reveals Astonishing Human Diversity

A partial human skull found at a site in Kenya suggests early humans living in Africa were incredibly diverse.

The 22,000-year-old skull is not a new species and is clearly that of an anatomically modern human, but is markedly different from similar finds from Africa and Europe from the same time, the researchers said.

"It looks like nothing else, and so it shows that original diversity that we've since lost," said study co-author Christian Tryon, a Paleolithic archaeologist at Harvard University's Peabody Museum in Cambridge, Massachusetts. "It's probably an extinct lineage."

The same site also contained deposits that are more than twice as old as the skull, including 46,000-year-old ostrich eggshells that were used to make beads. The new finds could reveal insights about the shifts in human culture that took place starting when the ancestors of present-day humans left Africa, around 50,000 years ago.

Mysterious period

About 12,000 years ago, humans began farming, living in denser settlements and burying their dead, so skeletons younger than that are plentiful, said Stanley Ambrose, an African archaeologist and paleoanthropologist at the University of Illinois at Urbana-Champaign, who was not involved in the study.

But relatively little is known about the people who came before them. Only a handful of human burials around the world date from about 12,000 to 30,000 years ago, Ambrose said.

To learn more about this lost period of human history, Tryon and his colleagues took a second look at specimens that were sitting in the collections of the National Museums of Kenya in Nairobi. The artifacts were unearthed in the 1970s at rock shelters at Lukenya Hill, a granite promontory that overlooks the savanna in Kenya.

Among the finds was the top portion of an ancient skull. The team took several measurements of the skull, then compared it with skulls fromNeanderthals, several other fossil human skulls from the same time and other periods, as well as those of modern-day humans.

Though the skull clearly belonged to a Homo sapien who was anatomically modern, its dimensions were markedly different from those of both the European skull and the African skulls from the same time. In addition, the skull was thickened, either from damage, nutritional stress or a highly active childhood. (There is not enough evidence to say the fossil represents a subspecies of Homo sapien, Tryon said.)

By measuring the ratio of radioactive isotopes of carbon (or carbon atoms with different numbers of neutrons), the team concluded that the skull was about 22,000 years old. That means the ancient human would have lived during the height of the last ice age.

Modern-day Africans have greater genetic diversity than other populations. But the new findings suggest that during this early period of human history, Africa may have supported even greater human diversity, with small, offshoot lineages that no longer exist today, Tryon said.

Light switch moment

Collections from deeper at the site revealed ostrich eggshells, which were used to make beads, as well as tiny stone blades known as Levallois technology. Many of the artifacts were somewhere between 22,000 and 46,000 years old.

The finds come from a dramatic moment in human history.

Around this time, many scientists believe that "this light switch goes on and people get smarter all of a sudden," Tryon told Live Science.

During the period between 20,000 and 50,000 years ago, people began intensively using elaborate trading routes over vast distances, fashioned decorative beads, and made lightweight stone points, that were not much different from arrow blades found in Egyptian tombs dating to about 4,000 years ago, Ambrose said.

"They're very simple little segments of blades that are easy to make, but they're very small and lightweight and they fit into little slots on the ends and sides of arrows," Ambrose told Live Science. "We know that the Egyptian ones had traces of poison on them."

The rediscovery of fragments from Lukenya Hill are important because evidence of human culture from this critical juncture is incredibly rare, Ambrose said.

The Lukenya Hill artifacts were described on Monday (Feb. 16) in the journal Proceedings of the National Academy of Sciences.
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Reference:

Ghose, Tia. 2015. “Stone Age Skull Reveals Astonishing Human Diversity”. Live Science. Posted: February 19, 2015. Available online: http://www.livescience.com/49875-stone-age-skull-found.html

Skulls Tell Story of Social Growth, Scientists Say

How did our early ancestors discover the wonders of art and music and culture so long ago? They found it, according to new research, because they had finally learned to be nicer to each other.

One critical change in the course of human evolution, according to the study, was a gradual reduction in the potency of testosterone, the bad boy among hormones responsible for aggressiveness and anti-social behavior.

A team of anthropologists at Duke University studied more than 1,400 skulls from the dawn of human history to the present and found evidence that the things we love so much -- art, tools, even jewelry -- resulted from the need to form clans and work together.

Robert Cieri, then a graduate student in biology, began the study three years ago at Duke, by examining 13 human skulls more than 80,000 years old and 41 skulls between 10,000 and 38,000 years old.

He and his colleagues also analyzed 1,367 20th century skulls from 30 ethnic populations in museums around the world. Cieri, now a doctoral candidate at the University of Utah, is the lead author of a paper published in the journal Current Anthropology.

The scientists found physiological changes in the skulls that most likely resulted from hormonal changes over many generations as humans slowly moved away from isolation and into social structures that required more cooperation. The need to work together gradually reduced the influence of testosterone, which in turn changed the physical structure of the skulls, the study contends.

The human skull became more feminine, with a gentler appearance.

Testosterone, like many hormones, plays a role in the physical development, even in the embryonic stage, both in humans and other mammals.

In humans, it partly determines the lengths of the second to fourth digits. Its effect on the cranium is dramatic, as documented in a famous experiment with Siberian silver foxes. The animals were bred only for tameness, yet the structure of their skulls changed, along with other body traits, over many generations as the foxes learned to trust humans as friends.

The human skulls examined by the Duke scientists also changed over generations as the brow lost its high ridge and the skull became rounder, and more feminine.

Those changes -- not just in appearance but in the influence of testosterone -- also made it possible for humans to build ever more complex societies that were more densely populated, eventually resulting in megacities.

The sequence is this: First the need to work together, less aggression, then cranial changes, then even less aggression as humans moved from individualistic hunter gatherers to farmers and finally to urban dwellers.

All of this is based on the study of skulls, but critics -- including some who are intimately familiar with the research -- point out that much more needs to be done before this idea is accepted in a scientific discipline noted for its wide range of varying opinion.

Indeed, how we became what we are today is one of the most hotly debated topics in science, largely because the evidence itself is problematic. Ancient skulls are dated primarily on the basis of known geological ages of the soils in which they were found, which is also open to different interpretations.

But the underlying theory that the development of social structures required humans to learn to get along is widely accepted. It is the most common explanation for a human characteristic that troubled Charles Darwin: altruism. If we are driven exclusively by a selfish drive to survive and pass our genes on to future generations, why would we help anyone else? Perhaps, because we need them.

No matter how we got here, the evidence is clear that art and music and tools go a long ways back in human history. They probably began around 50,000 years ago, according to anthropologists. Recent discoveries indicate they really exploded at least 30,000 years ago.

One spectacular example is the incredibly beautiful paintings found in a cave in southern France in 1994.

Some of the paintings, numbered in the hundreds, are up to 32,000 years old, and they are exquisite. Even then, the need to communicate and preserve what was deemed valuable must have been intense.

"If prehistoric people began living closer together and passing down new technologies, they'd have to be tolerant of each other," Cieri said in releasing the study. "The key to our success is the ability to cooperate and get along and learn from one another."

The cave paintings in France indicate we learned that very early. But the situation in the world today doesn't argue that we left the savage in us behind.

Last century was the bloodiest in human history. With two world wars and uncountable battles and skirmishes, more people died from violence during that era than in any other.

But at least we have tools and jewelry. And music. And those wonderful old paintings in France.
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References:

Dye, Lee. 2014. “Skulls Tell Story of Social Growth, Scientists Say”. ABC News. Posted: August 10, 2014. Available online: http://abcnews.go.com/Technology/skulls-story-social-growth-scientists/story?id=24920557

Stone Age Skull Unearthed with Bits of Brain Clinging to It

A Stone Age skull with what may be bits of brain clinging to it has been unearthed at an ancient hunter-gatherer site in Norway.

The skeletal fragment, which is about 8,000 years old, may have once belonged to an infant or a small child, though it is so packed into the soil that researchers still haven't been able to remove most of it, said Gaute Reitan, an archaeologist at the Museum of Cultural History in Oslo, Norway, who is excavating the site in conjunction with the University of Oslo.

The piece of skull was unearthed along with an adult's skeleton. These bones may represent one of the oldest Stone Age skeletons, and skulls, ever unearthed in Scandinavia, Reitan said.

Hints of ancient settlements

While doing archaeological exploration last year prior to construction of a convention center in southwestern Oslo, local archaeologists found signs of an ancient settlement and passed the information along to Reitan and his colleagues, who did additional excavation.

Several pits contained microblades, or tiny pieces of flint that would have fit into slots in bone or wooden arrows, as well as stone axes and pieces of rock crystal — a smooth, clear glass that Mesolithic people placed in their arrowheads, Reitan said.

These pieces shaped by the Mesolithic people "look like the cleanest glass from a bottle of Coke," Reitan said.

Other pits revealed hearths with burnt bones, as well as postholes that would have supported the wooden beams of a simple hut.

The finds suggest that the site was once a semipermanent hunter-gatherer settlement.

Though the ancient humans may have eaten deer and elk, they likely survived mostly on the water's bounty, guiding their log boats or canoes through the Oslo fjord to hunt for marine mammals and fish, Reitan said. "They were first and foremost fisherman," he added.

Child's skull?

In late June while excavating the same site, the team uncovered a man-size pit, roughly the shape of a bathtub, with the sides lined with stones. The pit was so tightly packed with sandy soil that it felt like concrete, Reitan said.

The burial contained one mostly intact skeleton, possibly from an adult male.

In that same pit, the team also found a fragment of what looked like the back of a child's skull, with bits of spongy, claylike "gray matter," clinging to it, Reitan said. Though it's still too early to say for sure, Reitan told Live Science he "can't think of anything else [it could be] but brain matter."

The burial also contained what look like deer antlers. Throughout the world, hunter-gatherers have placed deer antlers in the burials of loved ones, though the exact reason why has remained a mystery, Reitan said.

Stone Age fisherman

The discovery of the skeleton and skull may be among the oldest Stone Age skeletons in Scandinavia. The details of the burial — such as the wide, deeply dug pit and the potential deer antlers placed in the grave — resemble those of other Mesolithic sites from the region, he said.

"They shared much of the same religious beliefs and shared the same way of handling their dead," Reitan said. The concern and effort taken to dig a pit and leave goods for the deceased show the hints of ancient religious beliefs of Mesolithic people, he added.

Still, there is much more to learn about these long-gone hunter-gatherers. Though the archaeologists tentatively identified some of the artifacts buried in the pit, most of the bones are still embedded in clumps of soil. The team now must painstakingly brush and remove the tightly packed soil from around the bones to more thoroughly catalog the pit's contents, Reitan said.

Once they have documented all the bones from the burial, the researchers may conduct chemical and DNA testing on the bones. That testing could, in turn, reveal what the Stone Age fishermen ate, how the man and child (or infant) lived, and how they are related to other ancient people from around Europe.

The findings have not yet been published in a peer-reviewed journal.
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References:

Ghose, Tia. 2014. “Stone Age Skull Unearthed with Bits of Brain Clinging to It”. Livescience. Posted: August 5, 2014. Available online: http://www.livescience.com/47187-skull-with-brain-unearthed.html

Impact on mummy skull suggests murder

Analysis of archived mummy reveals murdered young female with Chagas disease

Blunt force trauma to the skull of a mummy with signs of Chagas disease may support homicide as cause of death, which is similar to previously described South American mummies, according to a study published February 26, 2014 in PLOS ONE by Stephanie Panzer from Trauma Center Murau, Germany, and colleagues, a study that has been directed by the paleopathologist Andreas Nerlich from Munich University.

For over a hundred years, the unidentified mummy has been housed in the Bavarian State Archeological Collection in Germany. To better understand its origin and life history, scientists examined the skeleton, organs, and ancient DNA using a myriad of techniques: anthropological investigation, a complete body CT scan, isotope analysis, tissue histology, molecular identification of ancient parasitic DNA, and forensic injury reconstruction.

Radiocarbon dated to around 1450 - 1640 AD, skeletal examination indicated that the mummy was likely 20-25 years old at the time of her death, and her skull exhibits typical Incan-type skull formations. Fiber from her hair bands appear to originate from South American llama or alpaca. Isotope analysis of nitrogen and carbon in her hair reveal a diet likely comprising maize and seafood, which, along with other evidence suggest South American origin and a life spent in coastal Peru or Chile. The mummy also showed significant thickening of the heart, intestines, and the rectum, features typically associated with chronic Chagas disease, a tropical parasitic infection. DNA analysis of parasites found in rectum tissue samples also support chronic Chagas disease, a condition she probably had since early infancy. The skull structure where a massive skull and face trauma occurred, suggests the trauma was acquired prior to death, and indicates massive central blunt force. The young Incan may have been victim of a ritual homicide, as has been observed in other South American mummies.
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References:

EurekAlert. 2014. “Impact on mummy skull suggests murder”. EurekAlert. Posted: February 26, 2014. Available online: http://www.eurekalert.org/pub_releases/2014-02/p-iom022514.php

Texas A&M study: Prehistoric ear bones could lead to evolutionary answers

The tiniest bones in the human body – the bones of the middle ear – could provide huge clues about our evolution and the development of modern-day humans, according to a study by a team of researchers that include a Texas A&M University anthropologist.

Darryl de Ruiter, a professor in the Department of Anthropology at Texas A&M, and colleagues from Binghamton University (the State University of New York) and researchers from Spain and Italy have published their work in the current issue of PNAS (Proceedings of the National Academy of Science).

The team examined the skull of a hominin believed to be about 1.9 million years old and found in a cave called Swartkrans, in South Africa. Of particular interest to the team were bones found in the middle ear, especially one called the malleus. It and the other ear bones – the incus and the stapes – together show a mixture of ape-like and human-like features, and represent the first time all three bones have been found together in one skull.

The malleus appears to be very human-like, the findings show, while the incus and stapes resemble those of a more chimpanzee-like, or ape-like creature. Since both modern humans and our early ancestors share this human-like malleus, the changes in this bone must have occurred very early in our evolutionary history.

"The discovery is important for two reasons," de Ruiter explains.

"First, ear ossicles are fully formed and adult-sized at birth, and they do not undergo any type of anatomical change in an individual lifetime. Thus, they are a very close representation of genetic expression. Second, these bones show that their hearing ability was different from that of humans – not necessarily better or worse, but certainly different.

"They are among the rarest of fossils that can be recovered," de Ruiter adds.

"Bipedalism (walking on two feet) and a reduction in the size of the canine teeth have long been held to be 'hallmarks of humanity' since they seem to be present in the earliest human fossils recovered to date. Our study suggests that the list may need to be updated to include changes in the malleus as well."

de Ruiter recently authored a series of papers in Science magazine that demonstrate the intermediate nature of the closely related species, Australopithecus sediba, and provide strong support that this species lies rather close to the ancestry of Homo sapiens. The current study could yield additional new clues to human development and answer key questions of the evolution of the human lineage.
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References:

EurekAlert. 2013. “Texas A&M study: Prehistoric ear bones could lead to evolutionary answers”. EurekAlert. Posted: May 13, 2013. Available online: http://www.eurekalert.org/pub_releases/2013-05/tau-tas051313.php

Lao skull earliest example of modern human fossil in Southeast Asia

An ancient skull recovered from a cave in the Annamite Mountains in northern Laos is the oldest modern human fossil found in Southeast Asia, researchers report. The discovery pushes back the clock on modern human migration through the region by as much as 20,000 years and indicates that ancient wanderers out of Africa left the coast and inhabited diverse habitats much earlier than previously appreciated.

The team described its finding in a paper in Proceedings of the National Academy of Sciences. The scientists, who found the skull in 2009, were likely the first to dig for ancient bones in Laos since the early 1900s, when a team found skulls and skeletons of several modern humans in another cave in the Annamite Mountains. Those fossils were about 16,000 years old, much younger than the newly found skull, which dates to between 46,000 and 63,000 years old.

"It's a particularly old modern human fossil and it's also a particularly old modern human for that region," said University of Illinois anthropologist Laura Shackelford, who led the study with anthropologist Fabrice Demeter, of the National Museum of Natural History in Paris. "There are other modern human fossils in China or in Island Southeast Asia that may be around the same age but they either are not well dated or they do not show definitively modern human features. This skull is very well dated and shows very conclusive modern human features," she said.

No other artifacts have yet been found with the skull, suggesting that the cave was not a dwelling or burial site, Shackelford said. It is more likely that the person died outside and the body washed into the cave sometime later, she said.

The find reveals that early modern human migrants did not simply follow the coast and go south to the islands of Southeast Asia and Australia, as some researchers have suggested, but that they also traveled north into very different types of terrain, Shackelford said.

"This find supports an 'Out-of-Africa' theory of modern human origins rather than a multi-regionalism model," she said. "Given its age, fossils in this vicinity could be direct ancestors of the first migrants to Australia. But it is also likely that mainland Southeast Asia was a crossroads leading to multiple migratory paths."

The discovery also bolsters genetic studies that indicate that modern humans occupied that part of the world at least 60,000 years ago, she said.

"This is the first fossil evidence that supports the genetic data," she said.

The researchers used radiocarbon dating and luminescence techniques to determine the age of the soil layers above, below and surrounding the skull, which was found nearly 2 1/2 meters (about 8.2 feet) below the surface of the cave.

Researchers at Illinois used uranium/thorium dating to determine the age of the skull, which they determined was about 63,000 years old.

Research fellow Kira Westaway, of Macquarie University in Australia (who dated the soils around the famous "hobbit" fossil found on Flores Island in Indonesia in 2003), conducted the luminescence analyses. These techniques measure the energy retained in crystalline particles in the soil to determine how much time has elapsed since the soil was last exposed to heat or solar radiation. She found that the layer of soil surrounding the fossil had washed into the cave between 46,000 and 51,000 years ago.

"Those dates are a bit younger than the direct date on the fossil, which we would expect because we don't know how long the body sat outside the cave before it washed in," Shackelford said.

"This fossil find indicates that the migration out of Africa and into East and Southeast Asia occurred at a relatively rapid rate, and that, once there, modern humans weren't limited to environments that they had previously experienced," she said. "We now have the fossil evidence to prove that they were there long before we thought they were there."
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References:

EurekAlert. 2012. "Lao skull earliest example of modern human fossil in Southeast Asia". EurekAlert. Posted: August 20, 2012. Available online: http://www.eurekalert.org/pub_releases/2012-08/uoia-lse081712.php

Multimillion-year-old skull may hold key to human origins

Scientists in Paris show 20-million-year-old skull they hope will help with the study of human ancestry.

Man may be a distant relatives of chimpanzees and bonobo monkeys, but scientists working in Uganda came back to Paris with a new addition to the primates' family picture.

Found amid the layers of sediment beneath the volcanoes of the Karamoja region, on the Napak XV hillside, scientists said the Ugandapithecus skull is the most complete of its kind to have ever been unearthed.

The discovery of the skull represents the culmination of more than 25 years of work and an arduous search process by paleontologists across grassy inclines.

"It's the first time we've got a real good sample of Ugandapithecus Major. Before that, it was known by jaw fragments, isolated teeth, a few postcranial bones. But here, we really have a good idea for the first time of what the whole skull might have looked like," said Dr Martin Pickford, one of the paleontologists who discovered the skull.

The fossil's position between various volcanic levels allows scientists to put an age to the skull, and despite the lack of tissue for DNA analysis, Dr Pickford estimates the its age at around 20 million years.

The British paleontologist said the discovery would allow scientists to fill a gap in the lineage of primates but said the Ugandapithecus could very well have become extinct without leading to the birth of man.

The discovery is also important in that it marks the first year of archeological excavation in Uganda without the need for military escorts.


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References:

2011. "Multimillion-year-old skull may hold key to human origins". Telegraph. Posted: September 19, 2011. Available online: http://www.telegraph.co.uk/science/science-news/8775512/Multimillion-year-old-skull-may-hold-key-to-human-origins.html

2,500-Year-Old Preserved Human Brain Discovered

A 2,500-year-old human skull uncovered in England was less of a surprise than what was in it: the brain. The discovery of the yellowish, crinkly, shrunken brain prompted questions about how such a fragile organ could have survived so long and how frequently this strange type of preservation occurs.

Except for the brain, all of the skull's soft tissue was gone when the skull was pulled from a muddy Iron Age pit where the University of York was planning to expand its Heslington East campus.

"It was just amazing to think that a brain of someone who had died so many thousands of years ago could persist just in wet ground," said Sonia O'Connor, a postdoctoral research fellow at the University of Bradford. O’Connor led a team of researchers who assessed the state of the brain after it was found in 2008 and looked into likely modes of preservation.

"It's particularly surprising, because if you talk to pathologists who deal with fresh dead bodies they say the first organ to really deteriorate and to basically go to liquid is the brain because of its high fat content," O'Connor said.

When it was found, the skull — which belonged to a man probably between 26 and 45 years old — was accompanied by a jaw and two neck vertebrae, bearing evidence of hanging and then decapitation. Cut marks on the inside of the neck indicate that the head was severed while there was still flesh on the bones, O'Connor said. There is, however, no indication of why he was hanged, and the rest of his remains have yet to be found.

More than a decade earlier, O'Connor was involved in the discovery of 25 preserved brains within medieval-era remains from Kingston-upon-Hull in England. Aside from the brains, only bones remained, and all other soft tissue was gone.

In this regard, the so-called Heslington brain and the medieval remains are quite different from mummies, frozen bodies, or intentionally preserved remains because in these cases other soft tissue — skin, muscles and so on — is preserved as well. None of the recently discovered remains showed any signs that they were intentional preserved.

The Heslington remains, along with others O'Connor has discovered, appear to have been buried quickly after death in wet environments where the absence of oxygen prevented the brain tissue from putrefying. But while the oxygen-free environment seems key, it is not possible to rule out other factors like certain diseases or physiological changes, such as those that accompany starvation, that might predispose the brain to being preserved this way, according to O'Connor.

After being deposited in the water-logged pit, the Heslington brain began to change chemically, developing into a durable material and shrinking to a quarter of its size. The chemical details of the new material are still under investigation, she said.

In a study in an upcoming issue of the Journal of Archaeological Science, O'Connor's team amassed a list of other, similarly preserved brains found since 1960. Reports like these typically fly under the radar and do not appear in the mainstream archaeological science publications, and when archaeologists do discover a preserved brain, they tend to think it is the first of such a find, she said.

"I think part of the problem is archaeologists are very happy to deal with humans' skeletal remains but as soon as there is any hint of soft tissue it is psychologically very, very different. You are no longer dealing with a skeleton, you are dealing with the remains of a corpse and, of course, a corpse is a dead individual," she said.

The skull has been dated to some time between 673 and 482 B.C.; Romans, meanwhile, arrived in the area in A.D. 71, according to Richard Hall, director of archaeology at the York Archaeological Trust, which the university hired to assess the site and handle the excavation in Heslington. This appears to have been a permanent settlement with ditches that divided the area into fields and walled parkways through which cattle could be driven, Hall told LiveScience.

Archaeologists have also found at the site circular features they believe were probably thatched-roof houses, as well as a pond-like feature probably used for water storage, he said.

At this point, the purpose of pits like the one in which the skull was found aren't clear, he said. No other human remains have been found on the site.

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References:

Parry, Wynne. 2011. "2,500-Year-Old Preserved Human Brain Discovered". Live Science. Posted: March 25, 2011. Available online: http://www.livescience.com/13410-prehistoric-brain-skull-preservation-decapitated-iron-age.html

Pictures: Prehistoric American Skull Found in Sea Cave?

Divers carefully place a marker near a human skull found upside down in a large underwater cave near the Caribbean Sea on Mexico's Yucatán Peninsula in 2007.

Based on the skull's location, the team believes the remains ended up there about 10,000 years ago—just before the then dry cave was inundated as sea level began rising. If confirmed, that age would make the skull one of the oldest known remains of an early American, or Paleo-Indian.

Though the skull was found alongside bones of a mastodon and other prehistoric animals in 2007, news of the find was released only late last month, to allow time to properly document the site, train the divers in archaeological practices, and coordinate with authorities.

The divers had previously seen Ice Age animal remains in surrounding caves, but the human skull was a surprise. "That's one of the beauties of exploration—you never know what you're going to find," diver Alberto Nava said.

Now comes the tricky part. "We want to figure out the story of Hoyo Negro and how the human and animal remains got there," said Nave, of the Projecto Espeleológico de Tulum (PET) organization and Global Underwater Explorers (GUE).

Read Skull in Underwater Cave May Be Earliest Trace of First Americans, the original article, by Fabio Esteban Amador regarding this skull as it was published February 18, 2011.
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References:

Than, Ker. 2011. "Pictures: Prehistoric American Skull Found in Sea Cave?". National Geographic Pictures. Posted: March 9, 2011. Available online: http://news.nationalgeographic.com/news/2011/03/pictures/110309-oldest-skull-americas-underwater-cave-mexico-mastodon-science-first/

Photo Credit: Daniel Riordan-Araujo