Thursday, May 29, 2014

Domestication of Dogs May Explain Mammoth Kill Sites and the Success of Early Modern Humans Main Content

A new analysis of European archaeological sites containing large numbers of dead mammoths and dwellings built with mammoth bones has led Penn State Professor Emerita Pat Shipman to formulate a new interpretation of how these sites were formed. She suggests that their abrupt appearance may have been due to early modern humans working with the earliest domestic dogs to kill the now-extinct mammoth -- a now-extinct animal distantly related to the modern-day elephant. Shipman's analysis also provides a way to test the predictions of her new hypothesis. Advance publication of her article "How do you kill 86 mammoths?" is available online through Quaternary International.

Spectacular archaeological sites yielding stone tools and extraordinary numbers of dead mammoths -- some containing the remains of hundreds of individuals -- suddenly became common in central and eastern Eurasia between about 45,000 and 15,000 years ago, although mammoths previously had been hunted by humans and their extinct relatives and ancestors for at least a million years. Some of these mysterious sites have huts built of mammoth bones in complex, geometric patterns as well as piles of butchered mammoth bones.

"One of the greatest puzzles about these sites is how such large numbers of mammoths could have been killed with the weapons available during that time," Shipman said. Many earlier studies of the age distribution of the mammoths at these sites found similarities with modern elephants killed by hunting or natural disasters, but Shipman's new analysis of the earlier studies found that they lacked the statistical evaluations necessary for concluding with any certainty how these animals were killed.

Surprisingly, Shipman said, she found that "few of the mortality patterns from these mammoth deaths matched either those from natural deaths among modern elephants killed by droughts or by culling operations with modern weapons that kill entire family herds of modern elephants at once." This discovery suggested to Shipman that a successful new technique for killing such large animals had been developed and its repeated use over time could explain the mysterious, massive collections of mammoth bones in Europe.
hand-drawn map
These maps show the locations of collections of mammoth bones at the archaeological sites that Pat Shipman analyzed in her paper that will be published in the journal Quaternary International. Credit: Jeffrey Mathison

The key to Shipman's new hypothesis is recent work by a team led by Mietje Germonpré of the Royal Belgian Institute of Natural Sciences, which has uncovered evidence that some of the large carnivores at these sites were early domesticated dogs, not wolves as generally had been assumed. Then, with this evidence as a clue, Shipman used information about how humans hunt with dogs to formulate a series of testable predictions about these mammoth sites.

"Dogs help hunters find prey faster and more often, and dogs also can surround a large animal and hold it in place by growling and charging while hunters move in. Both of these effects would increase hunting success," Shipman said. "Furthermore, large dogs like those identified by Germonpré either can help carry the prey home or, by guarding the carcass from other carnivores, can make it possible for the hunters to camp at the kill sites." Shipman said that these predictions already have been confirmed by other analyses. In addition, she said, "if hunters working with dogs catch more prey, have a higher intake of protein and fat, and have a lower expenditure of energy, their reproductive rate is likely to rise."

Another unusual feature of these large mammoth kill sites is the presence of extraordinary numbers of other predators, particularly wolves and foxes. "Both dogs and wolves are very alert to the presence of other related carnivores -- the canids -- and they defend their territories and food fiercely," Shipman explained. "If humans were working and living with domesticated dogs or even semi-domesticated wolves at these archaeological sites, we would expect to find the new focus on killing the wild wolves that we see there."

Two other types of studies have yielded data that support Shipman's hypothesis. Hervé Bocherens and Dorothée Drucker of the University of Tubingen in Germany, carried out an isotopic analysis of the ones of wolves and purported dogs from the Czech site of Predmostí. They found that the individuals identified as dogs had different diets from those identified as wolves, possibly indicating feeding by humans. Also, analysis of mitochondrial DNA by Olaf Thalmann of the University of Turku in Finland, and others, showed that the individuals identified as dogs have a distinctive genetic signature that is not known from any other canid. "Since mitochondrial DNA is carried only by females, this finding may indicate that these odd canids did not give rise to modern domesticated dogs and were simply a peculiar, extinct group of wolves," Shipman said. "Alternatively, it may indicate that early humans did domesticate wolves into dogs or a doglike group, but the female canids interbred with wild wolf males and so the distinctive female mitochondrial DNA lineage was lost."

As more information is gathered on fossil canids dated to between 45,000 and 15,000 years ago, Shipman's hunting-dog hypothesis will be supported "if more of these distinctive doglike canids are found at large, long-term sites with unusually high numbers of dead mammoths and wolves; if the canids are consistently large, strong individuals; and if their diets differ from those of wolves," Shipman said. "Dogs may indeed be man's best friend."

Thursday, May 15, 2014

Genetic study confirms link between earliest Americans and modern Native-Americans

The ancient remains of a teenage girl found in an underwater Mexican cave establish a definitive link between the earliest Americans and modern Native Americans, according to a new study released today in the journal Science.

The study was conducted by an international team of researchers from 13 institutions, including Deborah Bolnick, assistant professor of anthropology at The University of Texas at Austin, who analyzed DNA from the remains simultaneously with independent researchers at Washington State University and the University of Illinois at Urbana-Champaign.

The findings have major implications for our understanding of the origins of the Western Hemisphere’s first people and their relationship to contemporary Native Americans.

The most ancient human remains in the Americas have baffled scientists because their skulls are narrower and have other measurably different features from those of Native Americans. Some researchers have hypothesized that these individuals came to the Americas from as far away as Australia, Southeast Asia or Europe.

Bolnick and her colleagues Brian Kemp of Washington State University and Ripan Malhi of the University of Illinois at Urbana-Champaign analyzed the DNA from the tooth of the adolescent girl who fell into a sinkhole in Mexico’s Yucatán Peninsula more than 12,000 years ago. The remains were found surrounded by a variety of extinct animals more than 130 feet below sea level in Hoyo Negro, a deep pit within the Sac Actun cave system in the Yucatán.

In three separate labs, the researchers independently examined the tooth’s mitochondrial DNA, which is maternally inherited (passed down from mother to child).

Each of the labs found that the ancient girl belonged to a genetic lineage shared only by Native Americans. This is the first time researchers have been able to match a skeleton with an early American (or Paleoamerican) skull and facial characteristics with DNA linked to the hunter-gatherers who moved onto the Bering Land Bridge from northeast Asia between 26,000 and 18,000 years ago, spreading southward into North America sometime after 17,000 years ago.

“The Hoyo Negro girl was related to living Native Americans and has ancestry from the same Beringian population,” Bolnick says. “This study therefore provides no support for the hypothesis that Paleoamericans migrated from Southeast Asia, Australia or Europe. Instead, it shows that Paleoamericans could have come from Beringia, like contemporary Native Americans, even though they exhibit some distinctive skull and facial features. The physical differences between Paleoamericans and Native Americans today are more likely due to changes that occurred in Beringia and the Americas over the last 9,000 years.”

The study was led by Mexico’s National Institute of Anthropology and History, and coordinated by James Chatters, owner of Applied Paleoscience, an archaeological and paleontological consulting firm in Bothell, Wash.

The Hoyo Negro expedition will be featured in National Geographic magazine and on a National Geographic Television program airing on the PBS series “Nova” in 2015.

Monday, May 12, 2014

Prehistoric people of Europe used mind-altering substances to aid in communication with the spiritual world

Unlike modern Man, the prehistoric people of Europe did not use mind-altering substances simply for their hedonistic pleasure. The use of alcohol and plant drugs – such as opium poppies and hallucinogenic mushrooms – was highly regulated and went hand-in-hand with the belief system and sacred burial rituals of many preindustrial societies. Elisa Guerra-Doce of the Universidad de Valladolid in Spain contends that their use was an integral part of prehistoric beliefs, and that these substances were believed to aid in communication with the spiritual world. Guerra-Doce’s research appears in Springer’s Journal of Archaeological Method and Theory.

Despite the fact that the consumption of these substances is as ancient as human society itself, it is only fairly recently that researchers have started to look into the historical and cultural contexts in which mind-altering products were used in Europe. To add to the body of literature about the anthropology of intoxication in prehistoric European societies, Guerra-Doce systematically documented the cultural significance of consuming inebriating substances in these cultures.

In the research, four different types of archaeological documents were examined: the macrofossil remains of the leaves, fruits or seeds of psychoactive plants; residues suggestive of alcoholic beverages; psychoactive alkaloids found in archaeological artifacts and skeletal remains from prehistoric times; and artistic depictions of mood-altering plant species and drinking scenes. These remnants include bits of the opium poppy in the teeth of a male adult in a Neolithic site in Spain, charred Cannabis seeds in bowls found in Romania, traces of barley beer on several ceramic vessels recovered in Iberia, and abstract designs in the Italian Alps that depict the ritual use of hallucinogenic mushrooms.

Because Guerra-Doce mainly found traces of sensory-altering products in tombs and ceremonial places, she believes such substances are strongly linked to ritual usage. They were consumed in order to alter the usual state of consciousness, or even to achieve a trance state. The details of the rituals are still unclear, but the hypothesis is that the substances were either used in the course of mortuary rites, to provide sustenance for the deceased in their journey into the afterlife, or as a kind of tribute to the underworld deities.

She adds that the right to use such substances may have been highly regulated given that they were a means to connect with the spirit world, and therefore played a sacred role among prehistoric European societies.

“Far from being consumed for hedonistic purposes, drug plants and alcoholic drinks had a sacred role among prehistoric societies,” says Guerra-Doce. “It is not surprising that most of the evidence derives from both elite burials and restricted ceremonial sites, suggesting the possibility that the consumption of mind-altering products was socially controlled in prehistoric Europe.”

Thursday, May 8, 2014

'Rice theory' explains north-south China cultural differences, study shows

A new cultural psychology study has found that psychological differences between the people of northern and southern China mirror the differences between community-oriented East Asia and the more individualistic Western world – and the differences seem to have come about because southern China has grown rice for thousands of years, whereas the north has grown wheat.

"It's easy to think of China as a single culture, but we found that China has very distinct northern and southern psychological cultures and that southern China's history of rice farming can explain why people in southern China are more interdependent than people in the wheat-growing north," said Thomas Talhelm, a University of Virginia Ph.D. student in cultural psychology and the study's lead author. He calls it the "rice theory."

The findings appear in the May 9 issue of the journal Science.

Talhelm and his co-authors at universities in China and Michigan propose that the methods of cooperative rice farming – common to southern China for generations – make the culture in that region interdependent, while people in the wheat-growing north are more individualistic, a reflection of the independent form of farming practiced there over hundreds of years.

"The data suggests that legacies of farming are continuing to affect people in the modern world," Talhelm said. "It has resulted in two distinct cultural psychologies that mirror the differences between East Asia and the West."

According to Talhelm, Chinese people have long been aware of cultural differences between the north region and the southern, which are divided by the Yangtze River – the largest river in China, flowing west to east across the vast country. People in the north are thought to be more aggressive and independent, while people to the south are considered more cooperative and interdependent.

"This has sometimes been attributed to different climates – warmer in the south, colder in the north – which certainly affects agriculture, but it appears to be more related to what Chinese people have been growing for thousands of years," Talhelm said.

He notes that rice farming is extremely labor-intensive, requiring about twice the number of hours from planting to harvest as does wheat. And because most rice is grown on irrigated land, requiring the sharing of water and the building of dikes and canals that constantly require maintenance, rice farmers must work together to develop and maintain an infrastructure upon which all depend. This, Talhelm argues, has led to the interdependent culture in the southern region.

Wheat, on the other hand, is grown on dry land, relying on rain for moisture. Farmers are able to depend more on themselves, leading to more of an independent mindset that permeates northern Chinese culture.

Talhelm developed his rice theory after living in China for four years. He first went to the country in 2007 as a high school English teacher in Guangzhou, in the rice-growing south.

A year later, he moved to Beijing, in the north. On his first trip there, he noticed that people were more outgoing and individualistic than in the south.

"I noticed it first when a museum curator told me my Chinese was clearly better than my roommate's," Talhelm said. "The curator was being direct and a little less concerned about how her statement might make us feel."

After three years in China, including time as a journalist, he later went back as a U.Va. doctoral student on a Fulbright scholarship.

"I was pretty sure the differences I was seeing were real, but I had no idea why northern and southern China were so different – where did these differences come from?" Talhelm asked.

He soon found that the Yangtze was an important cultural divider in China. "I found out that the Yangtze River helped divide dialects in China, and I soon learned that the Yangtze also roughly divides rice farming and wheat farming," he said.

He dug into anthropologists' accounts of pre-modern rice and wheat villages and realized that they might account for the different mindsets, carried forward from an agrarian past into modernity.

"The idea is that rice provides economic incentives to cooperate, and over many generations, those cultures become more interdependent, whereas societies that do not have to depend on each other as much have the freedom of individualism," Talhelm said.

He went about investigating this with his Chinese colleagues by conducting psychological studies of the thought styles of 1,162 Han Chinese college students in the north and south and in counties at the borders of the rice-wheat divide.

They found through a series of tests that northern Chinese were indeed more individualistic and analytic-thinking – more similar to Westerners – while southerners were interdependent, holistic-thinking and fiercely loyal to friends, as psychological testing has shown is common in other rice-growing East Asian nations, such as Japan and Korea.

The study was conducted in six Chinese cities: Beijing in the north; Fujian in the southeast; Guangdong in the south; Yunnan in the southwest; Sichuan in the west central; and Liaoning in the northeast.

Talhelm said that one of the most striking findings was that counties on the north-south border – just across the Yangtze River from each other – exhibited the same north/south psychological characteristics as areas much more distantly separated north and south.

Friday, May 2, 2014

Neanderthals were not inferior to modern humans

If you think Neanderthals were stupid and primitive, it's time to think again.
The widely held notion that Neanderthals were dimwitted and that their inferior intelligence allowed them to be driven to extinction by the much brighter ancestors of modern humans is not supported by scientific evidence, according to a researcher at the University of Colorado Boulder.
Neanderthals thrived in a large swath of Europe and Asia between about 350,000 and 40,000 years ago. They disappeared after our ancestors, a group referred to as "anatomically modern humans," crossed into Europe from Africa.
In the past, some researchers have tried to explain the demise of the Neanderthals by suggesting that the newcomers were superior to Neanderthals in key ways, including their ability to hunt, communicate, innovate and adapt to different environments.
But in an extensive review of recent Neanderthal research, CU-Boulder researcher Paola Villa and co-author Wil Roebroeks, an archaeologist at Leiden University in the Netherlands, make the case that the available evidence does not support the opinion that Neanderthals were less advanced than anatomically modern humans. Their paper was published April 30, 2014 in the journal PLOS ONE.
"The evidence for cognitive inferiority is simply not there," said Villa, a curator at the University of Colorado Museum of Natural History. "What we are saying is that the conventional view of Neanderthals is not true."
Villa and Roebroeks scrutinized nearly a dozen common explanations for Neanderthal extinction that rely largely on the notion that the Neanderthals were inferior to anatomically modern humans. These include the hypotheses that Neanderthals did not use complex, symbolic communication; that they were less efficient hunters who had inferior weapons; and that they had a narrow diet that put them at a competitive disadvantage to anatomically modern humans, who ate a broad range of things.
The researchers found that none of the hypotheses were supported by the available research. For example, evidence from multiple archaeological sites in Europe suggests that Neanderthals hunted as a group, using the landscape to aid them.
Researchers have shown that Neanderthals likely herded hundreds of bison to their death by steering them into a sinkhole in southwestern France. At another site used by Neanderthals, this one in the Channel Islands, fossilized remains of 18 mammoths and five woolly rhinoceroses were discovered at the base of a deep ravine. These findings imply that Neanderthals could plan ahead, communicate as a group and make efficient use of their surroundings, the authors said.
Other archaeological evidence unearthed at Neanderthal sites provides reason to believe that Neanderthals did in fact have a diverse diet. Microfossils found in Neanderthal teeth and food remains left behind at cooking sites indicate that they may have eaten wild peas, acorns, pistachios, grass seeds, wild olives, pine nuts and date palms depending on what was locally available.
Additionally, researchers have found ochre, a kind of earth pigment, at sites inhabited by Neanderthals, which may have been used for body painting. Ornaments have also been collected at Neanderthal sites. Taken together, these findings suggest that Neanderthals had cultural rituals and symbolic communication.
Villa and Roebroeks say that the past misrepresentation of Neanderthals' cognitive ability may be linked to the tendency of researchers to compare Neanderthals, who lived in the Middle Paleolithic, to modern humans living during the more recent Upper Paleolithic period, when leaps in technology were being made.
"Researchers were comparing Neanderthals not to their contemporaries on other continents but to their successors," Villa said. "It would be like comparing the performance of Model T Fords, widely used in America and Europe in the early part of the last century, to the performance of a modern-day Ferrari and conclude that Henry Ford was cognitively inferior to Enzo Ferrari."
Although many still search for a simple explanation and like to attribute the Neanderthal demise to a single factor, such as cognitive or technological inferiority, archaeology shows that there is no support for such interpretations, the authors said.
But if Neanderthals were not technologically and cognitively disadvantaged, why didn't they survive?
The researchers argue that the real reason for Neanderthal extinction is likely complex, but they say some clues may be found in recent analyses of the Neanderthal genome over the last several years. These genomic studies suggest that anatomically modern humans and Neanderthals likely interbred and that the resulting male children may have had reduced fertility. Recent genomic studies also suggest that Neanderthals lived in small groups. All of these factors could have contributed to the decline of the Neanderthals, who were eventually swamped and assimilated by the increasing numbers of modern immigrants.