Friday, November 29, 2019

Unique sled dogs helped the inuit thrive in the North American Arctic


UC Davis anthropologists and geneticists traced dog's DNA back 2,000 years
University of California - Davis
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IMAGE: A team of Greenland sled dogs are descendants of the Inuit of North American Arctic. view more 
Credit: Article author Tatiana Tatiana Feuerborn
Inuit sled dogs have changed little since people migrated to the North American Arctic across the Bering Strait from Siberia with them, according to researchers who have examined DNA from the dogs from that time span. The legacy of these Inuit dogs survives today in Arctic sled dogs, making them one of the last remaining descendant populations of indigenous, pre-European dog lineages in the Americas.
The latest research is the result of nearly a decade's work by University of California, Davis, researchers in anthropology and veterinary genetics, who analyzed the DNA of hundreds of dogs' ancient skeletal remains to determine that the Inuit dog had significantly different DNA than other Arctic dogs, including malamutes and huskies.
The article, "Specialized sledge dogs accompanied the Inuit dispersal across the North American Arctic," was published Wednesday in the Proceedings of the Royal Society B: Biological Sciences. From UC Davis, authors include Christyann Darwent, professor of anthropology; Ben Sacks, adjunct professor and director of the Mammalian Ecology and Conservation Unit, Veterinary Genetics Laboratory, School of Veterinary Medicine; and Sarah Brown, a postdoctoral researcher. Lead author Carly Ameen is an archaeologist from the University of Exeter; Tatiana Feuerborn is with the Globe Institute in Denmark and Centre for Palaeogenetics in Sweden; and Allowen Evin is at the CNRS, Université de Montpellier, Institut des Sciences de l'Evolution in Montpellier, France. The list of authors includes many others from a large number of collaborating institutions.
Qimmiit (dogs in Inuktitut) were viewed by the Inuit as particularly well-suited to long-distance hauling of people and their goods across the Arctic and consuming local resources, such as sea mammals, for food.
The unique group of dogs helped the Inuit conquer the tough terrain of the North American Arctic 2,000 years ago, researchers said. Inuit dogs are the direct ancestors of modern Arctic sled dogs, and although their appearance has continued to change over time, they continue to play an important role in Arctic communities.
Experts examined the DNA from 921 dogs and wolves who lived during the last 4,500 years. Analysis of the DNA, and the locations and time periods in which they were recovered archaeologically, shows dogs from Inuit sites occupied beginning around 2,000 years ago were genetically different from dogs already in the region.
According to Sacks "the genetic profiles of ancient dogs of the American Arctic dating to 2,000 years ago were nearly identical to those of older dogs from Siberia, but contrasted starkly with those of more ancient dogs in the Americas, providing an unusually clear and definitive picture of the canine replacement event that coincided with the expansion of Thule peoples across the American Arctic two millennia ago."
Preserving an important history
Research confirms that native peoples maintained their own dogs. By analyzing the shape of elements from 391 dogs, the study also shows that the Inuit had larger dogs with a proportionally narrower cranium to earlier dogs belonging to pre-Inuit groups.
The National Science Foundation-funded portion of the research at UC Davis was inspired by Inuit activist and author Sheila Watt-Cloutier, who told Darwent about Inuit sled-dog culling undertaken by Canadian police in the 1950s and asked if there was a way to use scientific methods to tell the history and importance of sled dogs in the Arctic. Preservation of these distinctive Inuit dogs is likely a reflection of the highly specialized role that dogs played in both long-range transportation and daily subsistence practices in Inuit society.

Barbequed clams on the menu for ancient Puerto Ricans



Analysis of fossilized shells reveals cooking habits of Caribbean civilizations over 2500 years ago
Cardiff University
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IMAGE: Photographs of all shells analyzed in this study. view more 
Credit: Cardiff University
Scientists have reconstructed the cooking techniques of the early inhabitants of Puerto Rico by analysing the remains of clams.
Led by Philip Staudigel, who conducted the analysis as a graduate student at the University of Miami Rosenstiel School and is now a postdoctoral researcher at Cardiff University, the team has used new chemical analysis techniques to identify the exact cooking temperatures at which clams were cooked over 2500 years ago.
With cooking temperatures getting up to around 200oC according to the new analysis, the team believe the early Puerto Ricans were partial to a barbeque rather than boiling their food as a soup.
The study, which also involved academics from the University of Miami and Valencia College, has been published today in the journal Science Advances.
Whilst the results throw new light on the cultural practices of the first communities to arrive on the island of Puerto Rico, they also provide at least circumstantial evidence that ceramic pottery technology was not widespread during this period of history - it's likely that this would be the only way in which the clams could have been boiled.
Lead author of the study Dr Philip Staudigel, currently at Cardiff University's School of Earth and Ocean Sciences, said: "Much of peoples' identity draws upon on where they came from, one of the most profound expressions of this is in cooking. We learn to cook from our parents, who learned from their parents.
"In many parts of the world, written records extend back thousands of years, which often includes recipes. This is not the case in the Caribbean, as there were no written texts, except for petroglyphs. By learning more about how ancient Puerto Rican natives cooked their meals, we can relate to these long-gone peoples through their food."
In their study, the team analysed over 20kg of fossilised clam shells at the University of Miami's Rosenstiel School of Marine and Atmospheric Sciences Stable Isotope Lab, which were collected from an archaeological site in Cabo Rojo, Puerto Rico.
The pre-Arawak population of Puerto Rico were the first inhabitants of the island, arriving sometime before 3000 BC, and came from Central and/or South America. They existed primarily from fishing, hunting, and gathering near the mangrove swamps and coastal areas where they had settled.
The fossilised shells, dating back to around 700 BC, were cleaned and turned into a powder, which was then analysed to determine its mineralogy, as well as the abundance of specific chemical bonds in the sample.
When certain minerals are heated, the bonds between atoms in the mineral can rearrange themselves, which can then be measured in the lab. The amount of rearrangement is proportional to the temperature the mineral is heated.
This technique, known as clumped isotope geochemistry, is often used to determine the temperature an organism formed at but in this instance was used to reconstruct the temperature at which the clams were cooked.
The abundance of bonds in the powdered fossils was then compared to clams which were cooked at known temperatures, as well as uncooked modern clams collected from a nearby beach.
Results showed that that the majority of clams were heated to temperatures greater than 100°C - the boiling point of water - but no greater than 200°C. The results also revealed a disparity between the cooking temperature of different clams, which the researchers believe could be associated with a grilling technique in which the clams are heated from below, meaning the ones at the bottom were heated more than the ones at the top.
"The clams from the archaeological site appeared to be most similar to clams which had been barbequed," continued Dr Staudigel.
"Ancient Puerto Ricans didn't use cookbooks, at least none that lasted to the present day. The only way we have of knowing how our ancestors cooked is to study what they left behind. Here, we demonstrated that a relatively new technique can be used to learn what temperature they cooked at, which is one important detail of the cooking process."

Tuesday, November 26, 2019

Human migration out of Africa may have followed monsoons in the Middle East U



Last year, scientists announced that a human jawbone and prehistoric tools found in 2002 in Misliya Cave, on the western edge of Israel, were between 177,000 and 194,000 years old.
The finding suggested that modern humans, who originated in Africa, began migrating out of the continent at least 40,000 years earlier than scientists previously thought.
But the story of how and when modern humans originated and spread throughout the world is still in draft form. That's because science hasn't settled how many times modern humans left Africa, or just how many routes they may have taken.
A new study published this week [Nov. 25, 2019] in the Proceedings of the National Academy of Sciences by American and Israeli geoscientists and climatologists provides evidence that summer monsoons from Asia and Africa may have reached into the Middle East for periods of time going back at least 125,000 years, providing suitable corridors for human migration.
The likely timing of these northward monsoon expansions corresponds with cyclical changes in Earth's orbit that would have brought the Northern Hemisphere closer to the sun and led to increased summer precipitation. With increased summer precipitation there may have been increased vegetation, supporting animal and human migration into the region.
"It could be important context for experts studying how, why, and when early modern humans were migrating out of Africa," says lead author Ian Orland, a University of Wisconsin-Madison geoscientist now at the Wisconsin Geological and Natural History Survey, in the Division of Extension. "The Eastern Mediterranean was a critical bottleneck for that route out of Africa and if our suggestion is right, at 125,000 years ago and potentially at other periods, there may have been more consistent rainfall on a year-round basis that might enhance the ability of humans to migrate."
For as long as humans have kept records, winters have been wet and summers have been hot and dry in the Levant, a region that includes Israel, Syria, Lebanon, Jordan and Palestine. Before modern times, those hot, dry summers would have presented a significant barrier to people trying to move across the landscape.
Scientists, though, have found it difficult to determine what kinds of precipitation patterns might have existed in the prehistoric Levant. Some studies examining a variety of evidence, including pollen records, ancient lake beds, and Dead Sea sediments, along with some climate modeling studies, indicate summers in the region may have, on occasion, been wet.
To try to better understand this seasonality, Orland and colleagues looked at cave formations called speleothems in Israel's Soreq Cave. Speleothems, such as stalactites and stalagmites, form when water drips into a cave and deposits a hard mineral called calcite. The water contains chemical fingerprints called isotopes that keep a record, like an archive, of the timing and environmental conditions under which speleothems have grown.
Among these isotopes are different forms of oxygen molecules -- a light form called O16 and a heavy form called O18. Today, the water contributing to speleothem growth throughout much of the year has both heavy and light oxygen, with the light oxygen predominantly delivered by rainstorms during the winter wet season.
Orland and his colleagues hypothesized they might be able to discern from speleothems whether two rainy seasons had contributed to their growth at times in the past because they might show a similar signature of light oxygen in both winter and summer growth.
But to make this comparison, the scientists had to make isotope measurements across single growth bands, which are narrower than a human hair. Using a sensitive instrument in the UW-Madison Department of Geoscience called an ion microprobe, the team measured the relative amounts of light and heavy oxygen at seasonal increments across the growth bands of two 125,000-year-old speleothems from Soreq Cave.
This was the first time that seasonal changes were directly measured in a speleothem this old.
At the same time that Orland was in pursuit of geologic answers, his UW-Madison colleague in the Nelson Institute for Environmental Studies Center for Climatic Research, Feng He, was independently using climate models to examine how vegetation on the planet has changed with seasonal fluctuations over the last 800,000 years. Colleagues since graduate school, He and Orland teamed up to combine their respective approaches after learning their studies were complementary.
A previous study in 2014 from UW-Madison climatologist and Professor Emeritus John Kutzbach showed that the Middle East may have been warmer and wetter than usual during two periods of time corresponding roughly to 125,000 years ago and 105,000 years ago. Meanwhile, at a point in between, 115,000 years ago, conditions there were more similar to today.
The wetter time periods corresponded to peak summer insolation in the Northern Hemisphere, when Earth passes closer to the sun due to subtle changes in its orbit. The drier time period corresponded to one of its farthest orbits from the sun. Monsoon seasons tend to be stronger during peak insolation.
This provided He an opportunity to study high and low insolation rainfall during summer seasons in the Middle East and to study its isotopic signatures.
The climate model "fueled the summer monsoon hypothesis" because it suggested that "under these conditions, the monsoons could have reached the Middle East and would have a low O18 signature," He, a study co-author, says. "It's a very intriguing period in terms of climate and human evolution."
His model showed that northward expansion of the African and Asian summer monsoons was possible during this time period, would have brought significant rainfall to the Levant in the summer months, would have nearly doubled annual precipitation in the region, and would have left an oxygen isotope signature similar to winter rains.
At the same time, Orland's speleothem isotype analysis also suggested summers were rainier during peak insolation at 125,000 and 105,000 years ago.
For similar reasons, the Middle East may have also been warm and humid around 176,000 years ago, the researchers say -- about when the jawbone made its way to Misliya Cave. And before the jawbone, the previous oldest modern human fossils found outside of Africa were at Israel's Skh?l Cave, dating back between 80,000 and 120,000 years ago.
Overall, the study suggests that during a period of time when humans and their ancestors were exploring beyond the African continent, conditions may have been favorable for them to traverse the Levant.
"Human migration out of Africa occurred in pulses, which is definitely consistent with our idea that every time the Earth is closer to the sun, the summer monsoon is stronger and that's the climatic window that opened and provided opportunities for human migration out of Africa," says He.

Wednesday, November 20, 2019

Only eat oysters in months with an 'r'? Rule of thumb is at least 4,000 years old



GAINESVILLE, Fla. --- Foodie tradition dictates only eating wild oysters in months with the letter "r" - from September to April - to avoid watery shellfish, or worse, a nasty bout of food poisoning. Now, a new study suggests people have been following this practice for at least 4,000 years.
An analysis of a large shell ring off Georgia's coast revealed that the ancient inhabitants of St. Catherines Island limited their oyster harvest to the non-summer months.
How can scientists know when islanders were collecting oysters? By measuring parasitic snails.
Snails known as impressed odostomes, Boonea impressa, are common parasites of oysters, latching onto a shell and inserting a stylus to slurp the soft insides. Because the snail has a predictable 12-month life cycle, its length at death offers a reliable estimate of when the oyster host died, allowing Florida Museum of Natural History researchers Nicole Cannarozzi and Michal Kowalewski to use it as a tiny seasonal clock for when people collected and ate oysters in the past.
Stowaways on discarded oyster shells, the snails offer new insights into an old question about the shell rings that dot the coasts of Florida, Georgia, South Carolina and Mississippi.
"People have been debating the purpose of these shell rings for a very long time," said Cannarozzi, the study's lead author and Florida Museum environmental archaeology collection manager. "Were they everyday food waste heaps? Temporary communal feasting sites? Or perhaps a combination? Understanding the seasonality of the rings sheds new light on their function."
Cannarozzi and Kowalewski, Thompson Chair of Invertebrate Paleontology, analyzed oysters and snails from a 230-foot-wide, 4,300-year-old shell ring on St. Catherines Island and compared them with live oysters and snails. They found that island inhabitants were primarily harvesting oysters during late fall, winter and spring, which also suggested the presence of people on the island tapered off during the summer.
The seasonality of the shell ring may be one of the earliest records of sustainable harvesting, Cannarozzi said. Oysters in the Southeast spawn from May to October, and avoiding oyster collection in the summer may help replenish their numbers.
"It's important to look at how oysters have lived in their environment over time, especially because they are on the decline worldwide," she said. "This type of data can give us good information about their ecology, how other organisms interact with them, the health of oyster populations and, on a grander scale, the health of coastal ecosystems."
Cannarozzi said using impressed odostomes to gauge what time of year oysters were harvested offers an independent way to assess ancient patterns of oyster gathering. This approach can complement other archaeological methods, including stable isotope analysis and examining shell growth rings.
Kowalewski said the method could be applied to other marine invertebrate studies if the "timepiece" organism's life cycle meets several key requirements.
"If you have species with a lifespan of one year or less, consistent growth patterns and predictable spawning behavior, you could potentially use them as clocks as well," he said. "We might be able to use this type of strategy to reconstruct population dynamics or the natural history of various species, especially those that are extinct."
Cannarozzi and Kowalewski emphasized the importance of interdisciplinary collaboration in addressing longstanding research questions in new ways. Their project combined paleontology, the study of fossils and other biological remains, with archaeology, which emphasizes human history. Cannarozzi's specialization - environmental archaeology - also explores the close connections between humans and their natural resources.
"People have affected the distributions, life cycles and numbers of organisms over time," Cannarozzi said. "Understanding how people in the past interacted with and influenced their environment can inform our conservation efforts today."

Tuesday, November 19, 2019

Scientists use modern technology to understand how ochre paint was created in pictographs



Ochre, one of Earth's oldest naturally occurring materials, was often seen as a vivid red paint
University of Missouri-Columbia
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IMAGE: This is one of the pieces of rock art found at Babine Lake. It is representative of the rock art that was analyzed in the study. view more 
Credit: University of Missouri
Ochre, one of Earth's oldest naturally occurring materials, was often used as a vivid red paint in ancient rock art known as pictographs across the world. Despite its broad use throughout human history and a modern focus on how the artistic symbolism is interpreted, little research exists on the paint itself and how it was produced.
Now, scientists led by Brandi MacDonald at the University of Missouri are using archaeological science to understand how ochre paint was created by hunter-gatherers in North America to produce rock art located at Babine Lake in British Columbia. The study was published in Scientific Reports, a journal of Nature.
"Ochre is one of the only types of material that people have continually used for over 200,000 years, if not longer," said MacDonald, who specializes in ancient pigments. "Therefore, we have a deep history in the archeological record of humans selecting and engaging with this material, but few people study how it's actually made."
This is the first study of the rock art at Babine Lake. It shows that individuals who prepared the ochre paints harvested an aquatic, iron-rich bacteria out of the lake -- in the form of an orange-brown sediment.
In the study, the scientists used modern technology, including the ability to heat a single grain of ochre and watch the effects of temperature change under an electron microscope at MU's Electron Microscopy Core facility. They determined that individuals at Babine Lake deliberately heated this bacteria to a temperature range of approximately 750°C to 850°C to initiate the color transformation.
"It's common to think about the production of red paint as people collecting red rocks and crushing them up," MacDonald said. "Here, with the help of multiple scientific methods, we were able to reconstruct the approximate temperature at which the people at Babine Lake were deliberately heating this biogenic paint over open-hearth fires. So, this wasn't a transformation done by chance with nature. Today, engineers are spending a lot of money trying to determine how to produce highly thermo-stable paints for ceramic manufacturing or aerospace engineering without much known success, yet we've found that hunter-gatherers had already discovered a successful way to do this long ago."

Friday, November 15, 2019

Early DNA lineages from Finland shed light on the diverse origins of the contemporary population



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IMAGE: Medieval burial site of Kalmistomäki in Kylälahti, Hiitola in Russia. view more 
Credit: Stanislav Belskiy
A new genetic study carried out at the University of Helsinki and the University of Turku demonstrates that, at the end of the Iron Age, Finland was inhabited by separate and differing populations, all of them influencing the gene pool of modern Finns. The study is so far the most extensive investigation of the ancient DNA of people inhabiting the region of Finland.
In the study, genes were investigated from archaeological bone samples of more than one hundred individuals who lived between the 4th and 19th centuries AD. Most of the samples originated in the Iron Age and the Middle Ages. Mitochondrial DNA (mtDNA), which is passed down by mothers to all of their offspring, was extracted from the individuals, thus uncovering the population history of women.
Based on the findings, the people who inhabited Finland in the Iron Age (approximately 300-1300 AD) and the Middle Ages (approximately 1200-1500 AD) shared mitochondrial lineages with today's Finns. However, significant differences were seen in the genome of individuals buried in different burial sites in the Iron Age in particular. mtDNA lineages typical of Stone Age hunter-gatherers were common among those buried in Luistari, Eura (southwest Finland), and Kirkkailanmaki, Hollola (southern Finland). In Kylalahti, Hiitola (Republic of Karelia, Russia) and Tuukkala, Mikkeli (eastern Finland), the most common findings were lineages characteristic of ancient European farmer populations. The fifth Iron Age burial site included in the study is located in Levanluhta, western Finland. Many of the individuals buried there represented mtDNA lineages associated with the modern Sami.
"All of the above originally independent lineages remain common in Finland to this day. This indicates that the studied Iron Age populations have had an impact on the gene pool of contemporary Finns," says doctoral student Sanni Oversti from the Faculty of Biological and Environmental Sciences, University of Helsinki, Finland.
The researchers posit that the differences found in the Iron Age populations of western and eastern Finland are opposite to those found in today's Finns: the lineages associated with ancient farmers were more common in the east, while the lineages inherited from hunter-gatherers were more prevalent in the west. Farmer populations arriving in Finland not only from the west and south but also from the east provides a potential explanation for this.

Thursday, November 14, 2019

Alpine rock axeheads became social and economic exchange fetishes in the Neolithic

Universitat Autonoma de Barcelona
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IMAGE: Alpine rock axehead found at Harras, Thuringia, from the Michelsberg Culture (c. 4300-2800 ANE). view more 
Credit: Juraj Lipták, State Office for Heritage Management and Archaeology Saxony-Anhalt.
Axeheads made out of Alpine rocks had strong social and economic symbolic meaning in the Neolithic, given their production and use value. Their resistance to friction and breakage, which permitted intense polishing and a re-elaboration of the rocks, gave these artefacts an elevated exchange value, key to the formation of long-distance exchange networks among communities of Western Europe. Communities who had already begun to set the value of exchange of a product according to the time and effort invested in producing them.
This is what a study led by a research group at the Universitat Autònoma de Barcelona (UAB) indicates in regards to the mechanical and physical parameters characterising the production, circulation and use of a series of rock types used in the manufacturing of sharp-edged polished artefacts in Europe during the Neolithic (5600-2200 BCE).
The objective of the study was to answer a long debated topic: the criteria by which Alpine rocks formed part of an unprecedented pan-European phenomenon made up of long-distance exchange networks, while others were only used locally. Was the choice based on economic, functional or perhaps subjective criteria? Stone axeheads were crucial to the survival and economic reproduction of societies in the Neolithic. Some of the rocks used travelled over 1000 kilometres from their Alpine regions to northern Europe, Andalusia in southern Spain and the Balkans.
This is the first time a study includes in the specialised bibliography comparative data obtained by testing the resistance to friction and breakage of the rocks. These mechanical parameters have led to the definition of production and use values, which were then correlated with the distances and volumes of the rocks exchanged in order to obtain their exchange value. The results help understand the basic principles underlying the supply and distribution system of stone materials during the Neolithic in Western Europe, as well as its related economic logic.
"The reasons favouring the integration of specific rock types into these long-distance networks depended on a complex pattern of technological and functional criteria. This pattern was not solely based on economic aspects, their use value, but rather on the mechanical capacity to resist successive transformation processes, i.e. their production value, and remain unaltered throughout time", explains Selina Delgado-Raack, researcher at the Department of Prehistory, UAB, and first author of the article.
Supply System and Economic Logic
The study points to the diverging economic conception between the manufacturing of tools using other rocks and Alpine rock axeheads. Neolithic communities selected the most suitable raw materials available from all the resources in their region and knew each of their mechanical and physical characteristics. These tools normally travelled in a radius of 200 kilometres from where they originated and rarely went farther than 400-500 kilometres. Only Alpine rocks travelled further than those regional and economic limits.
"The circulation of these rocks at larger distances did not respond to a functional and cost-efficient logic, in which each agent takes into account the costs of manufacturing and transport when selecting the different rock types, all of them viable in being converted into fully functioning tools", indicates Roberto Risch, also researcher at the Department of Prehistory, UAB, and coordinator of the research. "It rather obeys the emergence of a very different economic reasoning, based on the ability to transform one material through ever greater amounts of work, something which many centuries later Adam Smith used to define the British economy of the 18th century. In the case of Alpine axeheads, their exceptional exchange value was due to the increase in manufacturing costs, a result of the intense polishing of these stones as they passed from one community to another".
A Primitive Form of Currency?
For the research team, the fact that the Alpine axeheads are categorised as the most commonly crafted and modified artefact in different periods and regions during the Neolithic rules out their role as symbols of power or ceremonial elements. "The economic pattern points towards more of a fetish object used in social and economic interactions among European communities of highly different socio-political productions and orientations", Selina Delgado-Raack states.
The exceptional exchange value reached by some rock types, such as the omphacitites and jadeitites, leads the team to think that they may have been used as a primitive form of currency, although they admit that there is a need for more studies before this topic can be clarified.