Trophy heads reveal Inca Empire’s reign of terror

By: Thomas Schmitt Attorney on August 31, 2019 / comment : 0 Americas, Archaeology, Chile, South America

The decapitated heads of young women from a prehistoric Andean village were put on display before they were discarded in a rubbish dump — possibly in an effort to terrorize people living under Incan rule.

The skulls, which were first excavated in 2003, displayed marks that suggest flesh was removed in order to mount them [Credit: F. Garrido & C. Morales 2019]

Francisco Garrido and Catalina Morales at the National Museum of Natural History in Santiago examined four skulls found at the ancient settlement of Iglesia Colorada, located in modern northern Chile.

Images of one skull show where holes were drilled, possibly to allow the skulls to be strung up in a display of violence. [Credit: F. Garrido & C. Morales 2019]

The researchers determined that three of the skulls belonged to girls or young women; the fourth skull belonged to a child of undetermined sex.

The skulls, which were first excavated in 2003, displayed marks that suggest flesh was removed in order to mount them [Credit: F. Garrido & C. Morales 2019]

Holes were punched into the skulls, probably so they could be strung on ropes. The skulls were eventually consigned to a rubbish pile amid food scraps and other debris.

The prehispanic village was the largest settlement in a region rich with copper that the Incans mined [Credit: F. Garrido & C. Morales 2019]

This treatment was carried out at roughly the same time that the Inca conquered Iglesia Colorada in the fifteenth or sixteenth century AD. The trophy heads might have been an imperial tactic for repressing local discontent, the authors say.

The study is published in the journal Latin American Antiquity.

Author: Diane Galistan | Source: Nature Research Journal [August 31, 2019]

20-million-year-old skull suggests complex brain evolution in monkeys, apes

By: Thomas Schmitt Attorney on August 21, 2019 / comment : 0 Anthropology, Chile, Fossils, Human Evolution

It has long been thought that the brain size of anthropoid primates--a diverse group of modern and extinct monkeys, humans, and their nearest kin--progressively increased over time. New research on one of the oldest and most complete fossil primate skulls from South America shows instead that the pattern of brain evolution in this group was far more checkered.

An exceptional fossil skull of Chilecebus carrascoensis, a 20-million-year-old primate from the Andes mountains of Chile [Credit: © AMNH/N. Wong and M. Ellison]

The study, published in the journal Science Advances and led by researchers from the American Museum of Natural History, the Chinese Academy of Sciences, and the University of California Santa Barbara, suggests that the brain enlarged repeatedly and independently over the course of anthropoid history, and was more complex in some early members of the group than previously recognized.

"Human beings have exceptionally enlarged brains, but we know very little about how far back this key trait started to develop," said lead author Xijun Ni, a research associate at the Museum and a researcher at the Chinese Academy of Sciences. "This is in part because of the scarcity of well-preserved fossil skulls of much more ancient relatives."

As part of a long-term collaboration with John Flynn, the Museum's Frick Curator of Fossil Mammals, Ni spearheaded a detailed study of an exceptional 20-million-year-old anthropoid fossil discovered high in the Andes mountains of Chile, the skull and only known specimen of Chilecebus carrascoensis.

"Through more than three decades of partnership and close collaboration with the National Museum of Chile, we have recovered many remarkable new fossils from unexpected places in the rugged volcanic terrain of the Andes," Flynn said. "Chilecebus is one of those rare and truly spectacular fossils, revealing new insights and surprising conclusions every time new analytical methods are applied to studying it."

Ancient DNA help scientists study human evolution: 'It's like a time capsule'

By: Thomas Schmitt Attorney on June 28, 2019 / comment : 0 Americas, Anthropology, Chile, Forensics, Genetics, South America

Archaeologists learn about the past by piecing together artifacts from material culture: the tools, artwork and architecture left behind that tell us how ancient humans lived. But imagine being able to study their DNA, to learn about how different groups of people were related to each other, where they came from or even what kinds of diseases they had?

Asst. Prof. Maanasa Raghavan, a geneticist at UChicago who started an ancient DNA lab, extracts and sequences genomes from skeletal remains of ancient individuals [Credit: Paola González Carvajal]

The concept of recovering DNA from ancient bones, especially those of humans and our evolutionary relatives, is still relatively new. Researchers can study the genome of modern-day populations of humans and extrapolate things about the past by comparing them to genomes of other groups. For example, if the genome of one group differs from a closely related group by a certain percentage, scientists could work backwards to calculate how long ago the two groups split, knowing the average amount of time it takes mutations, or random changes to genes, to accumulate.

But this approach requires making a lot of assumptions about the rate of genetic change and how these groups actually lived and interacted with each other. Asst. Prof. Maanasa Raghavan, a geneticist who recently joined the University of Chicago faculty to build an ancient DNA lab, wants to refine some of these assumptions and models by going straight to the source.

"Now we have the tools by which we can actually extract and sequence entire genomes directly from the skeletal remains of ancient individuals," she said. "It's like a time capsule from the time these people lived. Suddenly we have an anchoring point in the past, so you don't have to assume things anymore."

Being able to sequence ancient DNA provides a snapshot of those people at a specific point in time. Extracting this DNA starts by finding the right kinds of bones, like teeth or the small, dense bones of the inner ear (petrous bone), that preserve enough DNA inside. Researchers then grind a section or drill into the bone and prepare the resulting powder for DNA extraction and sequencing. It's a delicate, carefully controlled process. Raghavan's new lab is located in the sub-basement of the Gordon Center for Integrative Science, purposefully separated from other genetic labs to avoid contaminating the samples with modern DNA.

There are several ancient DNA labs around the world now, and the more samples Raghavan and her colleagues can analyze in an ethical, informed and sustainable manner, the higher-resolution picture they can create about how individuals and populations evolved over time. They can then layer in what we know from other fields like anthropology, archaeology, linguistics and ecology to see what effects cultural practices, population movements and mixing, and changes in the environment had on human genetic history.

An aerial view of the archaeological site “El Olivar”, Coquimbo Region, Chile. This site covers almost 700 years, including the period of contact with the Inca empire [Credit: Paola González Carvajal]

For example, one of Raghavan's first projects is to analyze ancient DNA samples from South Asia. This work is being done in close collaboration with Indian researchers and archaeologists. The region has been understudied because DNA generally doesn't preserve well in tropical environments. But as sampling and genetic sequencing tools have improved, researchers are able to find more and more usable ancient biological materials.

South Asian cultures have a history of caste systems and intermarriage between close relatives, which leads to higher rates of diseases caused by mutations in recessive genes. By studying ancient DNA from people who lived during different points in time, Raghavan and her team can compare the ancient genomic data to modern samples and infer how much intermarriage was happening in the past, and what effects it may have had on disease rates over time.

Likewise, they can use ancient data to understand how different populations of humans develop susceptibility to certain diseases. If genomic data from modern humans shows us that specific genetic changes make people susceptible to certain diseases, they can look for these same changes in the ancient DNA to see when and how this susceptibility might have evolved.

Raghavan's group is also working on projects to reconstruct the human population history of the Americas. One region of focus is Chile, where members of the group will study ancient human DNA from past cultures to understand whether cultural evolution correlated with human genetics. For example, were new cultures accompanied by new people migrating into the region and bringing with them new lifestyles and technology? How did these various populations interact, if at all, and did they contribute genes to present-day populations who live in in this region of South America?

Raghavan said this kind of detective work helps build a better understanding of how present-day populations are structured. Certain populations of people form subgroups because people tend to marry and reproduce within the same groups or cultures. Over time, this starts to create differences in the genome that may mean one of these groups is more prone to diseases (or protected from different diseases) than another. These fine distinctions can make a big difference in designing genome-wide association studies that compare different populations and look for genetic changes that might account for disease.

By looking into the past, Raghavan wants to learn the origins of diseases. Again, applying lessons from other fields of human study: Was there something about the environment that made ancient humans susceptible to disease? Or was there a dramatic change in their lifestyle?

"With the ability to get DNA from the past, we can actually start directly looking at changes in the genome over time and correlating them with environmental or lifestyle changes in the past," Raghavan said. "We can start better piecing together not just how humans evolved, but how they evolved within the environment they lived in at a particular time period and how that impacted the history of disease in our species."

Author: Matt Wood | Source: University of Chicago [June 28, 2019]

Oldest meteorite collection on Earth found in one of the driest places

By: Thomas Schmitt Attorney on May 23, 2019 / comment : 0 Chile, Earth Science, Geology, Palaeontology, South America

Earth is bombarded every year by rocky debris, but the rate of incoming meteorites can change over time. Finding enough meteorites scattered on the planet's surface can be challenging, especially if you are interested in reconstructing how frequently they land. Now, researchers have uncovered a wealth of well-preserved meteorites that allowed them to reconstruct the rate of falling meteorites over the past two million years.

The L6 ordinary chondrite El Medano 128, a 556 g meteorite recovered in the Atacama Desert [Credit: CCJ-CNRS, P. Groscaux]

"Our purpose in this work was to see how the meteorite flux to Earth changed over large timescales -- millions of years, consistent with astronomical phenomena," says Alexis Drouard, Aix-Marseille Université, lead author of the new paper in Geology.

To recover a meteorite record for millions of years, the researchers headed to the Atacama Desert. Drouard says they needed a study site that would preserve a wide range of terrestrial ages where the meteorites could persist over long time scales.

Large meteorite found in the Atacama Desert [Credit: Jerome Gattacceca (CEREGE)]

While Antarctica and hot deserts both host a large percentage of meteorites on Earth (about 64% and 30%, respectively), Drouard says, "Meteorites found in hot deserts or Antarctica are rarely older than half a million years." He adds that meteorites naturally disappear because of weathering processes (e.g., erosion by wind), but because these locations themselves are young, the meteorites found on the surface are also young.

"The Atacama Desert in Chile, is very old ([over] 10 million years)," says Drouard. "It also hosts the densest collection of meteorites in the world."

Meteorite with thin, dark, fusion crust in the Atacama Desert [Credit: Jerome Gattacceca (CEREGE)]

The team collected 388 meteorites and focused on 54 stony samples from the El Médano area in the Atacama Desert. Using cosmogenic age dating, they found that the mean age was 710,000 years old. In addition, 30% of the samples were older than one million years, and two samples were older than two million. All 54 meteorites were ordinary chondrites, or stony meteorites that contain grainy minerals, but spanned three different types.

"We were expecting more 'young' meteorites than 'old' ones (as the old ones are lost to weathering)," says Drouard. "But it turned out that the age distribution is perfectly explained by a constant accumulation of meteorites for millions years." The authors note that this is the oldest meteorite collection on Earth's surface.

Meteorite recovery campaign in the Atacama Desert, Nov. 2017 [Credit: Katherine Joy (University of Manchester)]

Drouard says this terrestrial crop of meteorites in the Atacama can foster more research on studying meteorite fluxes over large time scales. "We found that the meteorite flux seems to have remained constant over this [two-million-year] period in numbers (222 meteorites larger than 10 g per squared kilometer per million year), but not in composition," he says. Drouard adds that the team plans to expand their work, measuring more samples and narrowing in on how much time the meteorites spent in space. "This will tell us about the journey of these meteorites from their parent body to Earth's surface."

Source: Geological Society of America [May 23, 2019]

Oldest human footprint found in the Americas confirmed in Chile

By: Thomas Schmitt Attorney on April 27, 2019 / comment : 0 Americas, Archaeology, Chile, South America

A 15,600-year-old footprint discovered in southern Chile is believed to be the oldest ever found in the Americas, according to researchers.

An ancient footprint is pictured in Osorno, Chile after its discovery in 2010 [Credit: Universidad Austral de Chile, Laboratorio de Sitio Pilauco]

The footprint was first discovered in 2010 by a student at the Universidad Austral of Chile. Scientists then worked for years to rule out the possibility that the print may have belonged to some other species of animal, and to determine the fossil's estimated age.

Karen Moreno, a paleontologist with the Universidad Austral who has overseen the studies, said researchers had also found bones of animals near the site, including those of primitive elephants, but determined that the footprint was evidence of human presence.

A) Photography of the original sedimentary structure attributed to a human footprint that was excavated at the Pilauco site. A sediment lump is apparently embedded within the trackbed (star). Scale bar 5 cm. B) Three-dimensional model in dorsal  view with a virtual 45° tilt toward the south to facilitate the observation of profile lines 1–2, 3–4 and 5–6 drawn on the 3D model surface (123Catch from Autodesk and trial version of Rhino4, McNeel &Associates). C) Profile lines: [1–2]  crossing from the “heel”, “medial longitudinal arch” and “hallux”; [3–4] passing by the midline. Notice that the sediment lump is 2.1 cm high from the footprint base; and [5–6] line passing through the “heel”, “lateral longitudinal arch” and “lateral digits” [Credit: Karen Moreno et al. 2019]

Moreno said this was the first evidence of humans in the Americas older than 12,000 years.

"Little by little in South America we're starting to find sites with evidence of human presence, but this is this oldest in the Americas," she said.

The newer findings were published in the latest edition of the peer-reviewed scientific journal PLOS One.

Source: Reuters [April 27, 2019]

Solving the ancient mysteries of Easter Island

By: Thomas Schmitt Attorney on January 10, 2019 / comment : 0 Archaeology, Chile, Easter Island

The ancient people of Rapa Nui (Easter Island, Chile) built their famous ahu monuments near coastal freshwater sources, according to a team of researchers including faculty at Binghamton University, State University of New York.

Examples of the Easter Island statues, or moai [Credit: Dale Simpson, Jr.]

The island of Rapa Nui is well-known for its elaborate ritual architecture, particularly its numerous statues (moai) and the monumental platforms that supported them (ahu.) Researchers have long wondered why ancient people built these monuments in their respective locations around the island, considering how much time and energy was required to construct them. A team of researchers including Binghamton University anthropologist Carl Lipo used quantitative spatial modeling to explore the potential relations between ahu construction locations and subsistence resources, namely, rock mulch agricultural gardens, marine resources, and freshwater sources--the three most critical resources on Rapa Nui. Their results suggest that ahu locations are explained by their proximity to the island's limited freshwater sources.

"The issue of water availability (or the lack of it) has often been mentioned by researchers who work on Rapa Nui/Easter Island," said Lipo. "When we started to examine the details of the hydrology, we began to notice that freshwater access and statue location were tightly linked together. It wasn't obvious when walking around--with the water emerging at the coast during low tide, one doesn't necessarily see obvious indications of water. But as we started to look at areas around ahu, we found that those locations were exactly tied to spots where the fresh groundwater emerges -- largely as a diffuse layer that flows out at the water's edge. The more we looked, the more consistently we saw this pattern. Places without ahu/moai showed no freshwater. The pattern was striking and surprising in how consistent it was. Even when we find ahu/moai in the interior of the island, we find nearby sources of drinking water. This paper reflects our work to demonstrate that this pattern is statistically sound and not just our perception."


"Many researchers, ourselves included, have long speculated associations between ahu/moai and different kinds of resources, e.g., water, agricultural land, areas with good marine resources, etc.," said lead author Robert DiNapoli of the University of Oregon. "However, these associations had never been quantitatively tested or shown to be statistically significant. Our study presents quantitative spatial modeling clearly showing that ahu are associated with freshwater sources in a way that they aren't associated with other resources."

According to Terry Hunt of the University of Arizona, the proximity of the monuments to freshwater tells us a great deal about the ancient island society.

"The monuments and statues are located in places with access to a resource critical to islanders on a daily basis--fresh water. In this way, the monuments and statues of the islanders' deified ancestors reflect generations of sharing, perhaps on a daily basis--centered on water, but also food, family and social ties, as well as cultural lore that reinforced knowledge of the island's precarious sustainability. And the sharing points to a critical part of explaining the island's paradox: despite limited resources, the islanders succeeded by sharing in activities, knowledge, and resources for over 500 years until European contact disrupted life with foreign diseases, slave trading, and other misfortunes of colonial interests."

The researchers currently only have comprehensive freshwater data for the western portion of the island and plan to do a complete survey of the island in order to continue to test their hypothesis of the relation between ahu and freshwater.

The paper, “Rapa Nui (Easter Island) monument locations explained by freshwater sources,” was published in PLOS ONE.

Source: Binghamton University [January 10, 2019]

The first rains in centuries in the Atacama Desert devastate its microbial life

By: Thomas Schmitt Attorney on November 14, 2018 / comment : 0 Astrobiology, Chile, Climate Change, Ecosystems, Environment, Natural Heritage, Wildlife

The Atacama Desert, the driest and oldest desert on Earth, located in northern Chile, hides a hyper-arid core in which no rain has been recorded during the past 500 years. But this situation has changed in the last three years: for the first time, rainfall has been documented in the hyper-arid core of the Atacama and, contrary to what was expected, the water supply has caused a great devastation among local life. This is the main conclusion of an international study, published in Scientific Reports and entitled "Unprecedented rains decimate surface microbial communities in the hyperarid core of the Atacama Desert", and directed by researchers from the Center for Astrobiology (CAB), a mixed center of the Spain's Higher Council for Scientific Research (CSIC) and the National Institute of Aerospace Technology (INTA). These recent rains are attributed to changing climate over the Pacific Ocean.

Atacama Desert [Credit: Carlos Gonzalez Silva]

"Our group has discovered that, contrary to what could be expected intuitively, the never-before-seen rainfall has not triggered a flowering of life in Atacama, but instead the rains have caused enormous devastation in the microbial species that inhabited the region before the heavy precipitations", explains Dr. Alberto G. Fairén.

"Our work shows that high rainfall has caused the massive extinction of most indigenous microbial species. The extinction range reaches 85%, as a result of the osmotic stress that has caused the sudden abundance of water: the autochthonous microorganisms, which were perfectly adapted to thrive under conditions of extreme dryness and had strategies optimized for the extraction of the scarce humidity of their environment, have been unable to adapt to the new conditions of sudden flooding and have died from excess water", adds Fairén.

From Atacama to Mars

This study represents a great advance to understand the microbiology of extremely arid environments. It also presents a new paradigm to decode the evolutionary path of a hypothetical early microbiota of Mars, since Mars is a hyper-arid planet that experienced catastrophic floods in ancient times.

"Mars had a first period, the Noachian (between 4.5 and 3.5 billion years ago), in which there was a lot of water on its surface," says Fairén. "We know this from the enormous amount of hydrogeological evidence still present in the Martian surface, in the form of ubiquitous hydrated minerals, traces of dried rivers and lakes, deltas, and perhaps a hemispheric ocean in the northern plains," explains Fairén.

Mars eventually lost its atmosphere and its hydrosphere, and became the dry and arid world we know today. "But at times during the Hesperian period (from 3.5 to 3 billion years ago), large volumes of water carved its surface in the form of outflow channels, the largest channels in the Solar System. If there were still microbial communities withstanding the process of extreme drying, they would have been subjected to processes of osmotic stress similar to those we have studied in Atacama", Fairén details.

"Therefore, our Atacama study suggests that the recurrence of liquid water on Mars could have contributed to the disappearance of Martian life, if it ever existed, instead of representing an opportunity for resilient microbiota to bloom again", adds Fairén.

In addition, this new study notes that large deposits of nitrates at the Atacama Desert offer evidence of long periods of extreme dryness in the past. The nitrates were concentrated at valley bottoms and former lakes by sporadic rains about 13 million years ago, and can be food for microbes. The Atacama nitrates may represent a convincing analog to the nitrate deposits recently discovered on Mars by the rover Curiosity (and reported in a 2015 study entitled "Evidence for indigenous martian nitrogen in solid samples from the Curiosity rover investigations at Gale crater", in the Proceedings of the National Academy of Sciences). Earlier this year, Fairén and colleagues discovered that short-term wetter environments in early Mars, occurring sporadically in a generally hyperdry early planet, explains the observed martian mineralogy.

"These long periods of dryness, followed by short-term wetter conditions, may also be in the origin of the nitrate deposits on Mars", concludes Fairén.

Source: Spanish National Research Council [November 14, 2018]

Chile to ask Britain's Natural History Museum to return extinct mammal remains

By: Thomas Schmitt Attorney on November 05, 2018 / comment : 0 Chile, Fossils, Heritage, Palaeontology, South America, UK

Chile announced on Sunday that it will ask the Natural History in London to return the remains of a mylodon, an extinct mammal that lived in Patagonia about 10,000 years ago.

Megatherium americanum skeleton, Natural History Museum, London [Credit: Ballista/WikiCommons]

Minister of National Assets Felipe Ward will travel in two weeks to London for talks over the remains of the ground sloth that roamed in the southern region shared by Argentina and Chile.

"We hope to have talks with the museum authorities... and seek to repatriate the mylodon's remains; these are bones and skin that are in storage, not even being exhibited," Ward told reporters.

The remains of the mylodon were taken to Britain in 1897 for research but were never returned to Chile, according to officials.

The mylodon was an ancestor of the sloth that measured about 2.5 meters (more than eight feet) and weighed about 3 tons.

German settlers discovered in 1896 remains of the mammal in a cave now known as "the cave of the mylodon," in the region of Magallanes, about 3,500 kilometers (2,175 miles) south of Santiago

On the trip to London, Ward will be joined by a delegation seeking the return of a statue important to the indigenous people of Easter Island, part of Chile.

They want to sculpt a replacement for the museum and recover the original, which was stolen from the island in 1868 by the English ship Topaze.

It is estimated that this moai, as the statues are known, was created between the year 1,000 and 1,600.

Chile also plans to ask the Kon-Tiki Museum in Oslo to return a large collection of historical pieces from Easter Island.

Source: AFP [November 05, 2018]