80beats » Human Origins

X-Rayed Mummies Reveal That Ancient Egyptians Had Heart Disease

Andrew Moseman — Wed, 18 Nov 2009 15:36:57 +0000

The elites of ancient Egypt had money, power, divine status in the case of the pharaohs, and also heart disease. In a study in today’s issue of The Journal of the American Medical Association, a team of researchers reports performing x-ray scans of 20 Egyptian mummies and finding them rife with cardiovascular disease like clogged arteries, one of the commonest ailments in modern American society.

On a visit to the Museum of Egyptian Antiquities in Cairo, one of the researchers had been intrigued by a nameplate on the remains of Pharaoh Merenptah, who died in 1,203BC. The plate said the pharaoh died at the age of 60 and suffered diseased arteries, arthritis and tooth decay [The Guardian]. So the scientists obtained permission to scan that mummy and others in the museum collection.

The common people of ancient Egypt weren’t mummified; only elites like royal families, their nursemaids, and priests got such a treatment. The elites ate salted fish, bread, and cheese like everyone else, but they also dined on rich foods such as cow, sheep, and goat meat, as well as honey and cakes with butter, says Abdel Nureldin, a professor of Egyptology at Cairo University, who worked on the investigation. At the same time, virtually no one in ancient times was sedentary, and that may have helped counteract their fatty diets [ScienceNOW Daily News].

Still, the researchers found, 16 of the 20 x-rayed mummies showed signs of heart disease. Men and women were affected equally. The most ancient of the mummies afflicted with atherosclerosis was Lady Rai, who had been a nursemaid to Queen Ahmose Nefertiti. She died at the age of 30 or 40 around 1530 BC, about 300 years prior to the time of Moses and 200 years before King Tut [Los Angeles Times].

Because only elite Egyptians were preserved so well after death, researchers can’t say how widespread cardiovascular disease might have been in the ancient society, or the ancient world at large. But what the finding does tell them is that while heart disease is exacerbated by the overindulgent and sedentary style of modern life, there’s more to it than that.

Image: Michael I. Miyamoto

Men Are Far More Likely to Abandon a Seriously Ill Spouse

Eliza Strickland — Thu, 12 Nov 2009 18:01:48 +0000

It started as an observation in a Seattle cancer ward, where oncologist Marc Chamberlain noticed that his male patients were often receiving steadfast support from their wives, while his female patients often didn’t have husbands hovering at their bedsides. Based on this anecdotal evidence, Chamberlain decided to investigate divorce rates among couples where one person had recently been diagnosed with a serious illness. His findings raise troubling questions about the loyalty of the male sex.

The study included diagnoses of both cancer and multiple sclerosis and found an overall divorce rate of nearly 12 percent, which is similar to that found in the normal population. But when the researchers looked at gender differences, they found the rate was nearly 21 percent when women were the patients compared with about 3 percent when men got the life-threatening diagnosis. The researchers suggest men are less able to commit, on the spot, to being caregivers to a sick partner, while women are better at assuming such home and family responsibilities [LiveScience]. However, the study did find that the divorce rate was lower in longer marriages.

Chamberlain notes that the study, which will be published in the journal Cancer, didn’t have any information about how happy the marriages were to begin with. “All these patients were couples when we met them, but we don’t know about pre-diagnosis marital conflicts that had been festering,” Dr. Chamberlain said. “But the striking part is with life threatening illness, how often women are abandoned compared to men. That does not speak very well of my gender” [The New York Times].

The researchers say that doctors may want to advise couples to seek family therapy after the woman receives a serious diagnoses, and note that the medical benefits of having a committed spouse are real and measurable. Researchers also looked at the quality of life among the patients who separated or divorced. They found these patients used more anti-depressants, took part less in clinical trials, had more frequent hospitalizations, were less likely to complete radiation therapy and more likely not to die at home [Reuters].

Image: iStockphoto

Lesson of the Ancient Nazcas: Deforestation Can Kill a Civilization

Eliza Strickland — Tue, 03 Nov 2009 11:36:58 +0000

From an ancient Peruvian civilization comes this warning: Don’t chop down all your trees, or there will be hell to pay.

The Nazca people are famous for the enormous earthworks they carved into an arid plateau, in designs that range from simple geometrical forms to representations of animals like hummingbirds, lizards, and monkeys. They were previously known to have disappeared around A.D. 500, when massive floods powered by El Niño ravaged the valley where they made their home. Now, a new study that examined the pollen in buried layers of soil in order to trace the horticultural history of the land may have revealed why those floods were so devastating.

The Ica Valley, about 120 miles south of Lima, is barren today but was once a riverine oasis — a fertile landscape capable of supporting many people. The key to that fertility was a tree called the huarango [Los Angeles Times]. The huarango tree provided wood for building and fuel, and seed pods that can be ground up and used in flour or beer. Its branches caught the water in morning mists, and its roots stabilized the topsoil. Says lead researcher David Beresford-Jones: “These were very special forests…. It is the ecological keystone species in the desert zone enhancing soil fertility and moisture and underpinning the floodplain with one of the deepest root systems of any tree known” [BBC News].

The new study, published in the journal Latin American Antiquity, found that the pollen in the older layers of soil came almost entirely from huarango trees. But by A.D. 400, pollen from corn and cotton plants had replaced the tree pollen, suggesting that the Nazca people had chopped down the forests to make room for agricultural fields. About AD 500, a major El Niño built up in the Pacific, deluging the nearby Andes with rain. Walls of water and mud washed down the valley and over the denuded landscape, sweeping away food crops, buildings and artifacts. Beresford-Jones compared it with the 1997-98 El Niño, which left the city of Ica 6 feet underwater [Los Angeles Times]. The floods of A.D. 500 were many times worse, the researchers say.

In the soil layers that came directly after the flood, the only pollen came from salt-tolerant plants that could survive in the arid conditions left behind in the aftermath of the natural disaster. The land was clearly no longer able to support agriculture, and the Nazca people vanished. But although the El Niño floods were dramatic, they didn’t have to mark the end of a civilization, the researchers say. “The landscape only became exposed to the catastrophic effects of that El Nino flood, once people had inadvertently crossed an ecological threshold,” explains Dr Beresford-Jones. “Such thresholds or ‘tipping-points’ are sharply defined in these desert environments” [BBC News]. The study refutes the notion that pre-Columbian people always lived in perfect harmony with nature, the researchers say–and also serves as a reminder that medding with the ecosystem can have devastating consequences.

Image: Alex Chepstow-Lusty

Much-Hyped Primate Fossil “Ida” Probably Isn’t Our Ancestor

Eliza Strickland — Wed, 21 Oct 2009 21:44:15 +0000

Surprise, surprise. An independent analysis of the primate fossil that was unveiled amid extraordinary hype last May has found significant evidence that the lemur-like creature was not a direct ancestor of humans, after all. The 47-million-year old fossil described in May, which was given the scientific name Darwinius masillae and nicknamed Ida, was announced with unrestrained razzmatazz. She was the “eighth wonder of the world”, “our Mona Lisa” and an evolutionary “Rosetta Stone”, according to the researchers who unveiled her…. She was, they said, the “link” between us and the rest of the animal kingdom [The Guardian].

But Ida, who was the subject of both a book and a TV special that were released at the same time as the scientific paper describing the fossil, failed to wow many evolutionary biologists. Says Erik Seiffert, lead researcher of the new study: ”The suggestion that Ida [was]… specifically related to the higher primates, namely monkeys, apes and humans, was actually a minority view from the start. So it came as a surprise to many of us who are studying primate palaeontology” [BBC News].

Seiffert’s new analysis began with his attempt to identify another fossil primate, Afradapis longicristatus, which he found to be a close relation to Darwinius. The researchers then compared 360 specific anatomical features of 117 living and extinct primate species to draw up a family tree [AP]. The analysis showed that both primates are located on an early twig of the branch that produced lemurs, and far from the lineage that spawned monkeys and great apes [Wired.com]. What’s more, the researchers say that both species have no modern descendants.

The new study, published in Nature, challenges the previous notion that Darwinius was an important part of our lineage. The previous researchers had singled out features in Ida’s face, teeth, and feet that were similar to those seen in higher apes, but the new research team argues that these features may be a result of “convergent evolution.” This involves features arising independently in separate lineages, possibly as a response to similar evolutionary pressures [BBC News].

The researchers involved in the Darwinius work stand by their findings, and still maintain that Ida is a find of spectacular proportions. They also note that the Darwinius skeleton is much more complete than Afradapis and shows additional higher primate characteristics not available for analysis on Seiffert’s fossils, such as bones in the foot [The Scientist].

But Seiffert says that Darwinius played no role in the origins of man, and is much more closely related to lemurs and lorises. Says Seiffert: “The last common ancestor that Darwinius shared with us was the same common ancestor that gave rise to all primates” [The Scientist].

Image: E.R.Seiffert, Stony Brook University

Scientist Smackdown: Did a Comet Explode Over Prehistoric North America?

Brett Israel — Mon, 19 Oct 2009 11:00:51 +0000

According to a theory proposed in 2007, the explosion of a comet over North America killed off the Clovis people and many of the continent’s largest mammals nearly 13,000 years ago. Not so fast, says a new study published in the Proceedings of the National Academy of Sciences, fueling a WWE-style stare down between the opposing camps.

The new report explains that archaeologists have examined sediments at seven Clovis-age sites across the United States, and found that the concentration of magnetic debris was insufficient to confirm an extraterrestrial impact at that time [Nature News]. The original theory’s evidence came from magnetic microspherules, or cosmic debris, discovered in sediments at 25 locations. However, one of the new study’s authors, Todd Surovell, said that even after 18 months of sedimentary analysis and hundreds of hours peering into a microscope, he could find no evidence of microspherules to support the the exploding comet theory. Snap.

But the research team that proposed the comet theory isn’t backing down. “Their study doesn’t negate our hypothesis,” says James Kennett, a palaeoceanographer at the University of California, Santa Barbara… Another co-author, geophysicist Allen West of Prescott, Arizona, says that Surovell’s group didn’t use the correct techniques to extract, identify and quantify the microspherules [Nature News]. Burn.

This isn’t the first challenge to the North American comet theory. A study in February found no evidence of burning biomass that a comet explosion, and the resulting continent-wide fire, would have produced. Kennett, one of the researchers who originally proposed the theory, responded by saying the contradictory studies are “flawed” and published a study in August on his team’s finding of nanometer-sized diamonds, supposedly created during the comet’s impact.

Scientists on both sides of the scuffle have new research scheduled for publication soon, so stay tuned!

Image: NASA

For Ancient Rome, Buried Treasure Means an Empire in Crisis

Brett Israel — Tue, 06 Oct 2009 15:31:39 +0000

Historians believe they’re settled a long-running debate over ancient Rome’s population at the turn of the 1st century B.C.E. thanks to stashes of ancient Roman coins. This was the period marked by Julius Caesar’s assassination and the Roman empire’s collapse, but surprisingly, historical records during the war-torn era show a population explosion in Rome. Census data, thought to only account for males, gives a population increase from 400,000 in 2nd century B.C.E. to between 4 and 5 million at the 1st century B.C.E.

But some historians argue that the population didn’t really increase, and that in fact it declined during this period because of the wars. To back up their idea they are turning to buried treasure. In times of instability in the ancient world, people stashed their cash and if they got killed or displaced, they didn’t come back for their Geld. Thus, large numbers of coin hoards are a good quantitative indicator of population decline, two researchers argue in in the Proceedings of the National Academy of Sciences Monday [Wired.com].

Over the years, archaeologists armed with metal detectors have found hundreds of clay pots filled with Roman coins. So a research team combined numbers of coin hoards from 250 B.C.E. to 100 B.C.E. with data from the Roman Republic censuses to understand how spikes in stashes reflected population changes. For example, population dropped by about 50,000 during the Second Punic War from 218 B.C.E. to 201 B.C.E., and that coincides with a jump in coin hoards dated to that time. Then, from data on coins hoarded from 100 B.C.E. to 50 C.E., the researchers inferred population during that era. The range predicted by the coin hoard model…[indicate] that civil wars culled about 100,000 people from the Roman populace [ScienceNOW Daily News].

So the data supports the idea that Rome’s population actually declined during the second century B.C.E. The researchers suggest that the large census numbers can be explained if the census was expanded to include women and children during this time, thus accounting for the large population increase in Rome during times of war. By these estimates the entire population of the Roman Empire—and not just its male population—was somewhere around 4 million to 5 million people by the end of the first century B.C. [LiveScience].

Image: iStockPhoto

A Fossil Named Ardi Shakes Up Humanity’s Family Tree

Eliza Strickland — Thu, 01 Oct 2009 16:57:03 +0000

Humanity has a new matriarch: a hominid named Ardi who lived in Ethiopia 4.4 million years ago. Anthropologists have unveiled the results of 17 years of research on a new species named Ardipithecus ramidus, presenting a rich trove of fossils including the partial skeleton of the small-brained, 110-pound female. Ardi is 1.2 million years older than the famed “Lucy,” of the species Australopithecus afarensis, and experts say the find fundamentally changes our understanding of human evolution.

Study coauthor Tim White says that Ardi provides clues to what the last common ancestor shared by humans and chimps might have looked like before their lineages diverged about 7 million years ago…. But despite being “so close to the split,” says White, the surprising thing is that she bears little resemblance to chimpanzees, our closest living primate relatives [Time].

Ardi’s pelvis, leg, and feet bones indicated that she walked upright on two feet, but her opposable big toes suggest that she was also comfortable climbing trees. Her hand, arm, and shoulder bones indicate that she didn’t often swing through the trees, though; instead she probably walked on her palms along tree branches like some extinct apes. Based on Ardi’s anatomy, it appears that chimpanzees may actually have evolved more than humans — in the scientific sense of having changed more over the past 7 million years or so [Time].

In a special issue of the journal Science that will be published later today, researchers present 11 papers covering many aspects of Ardipithecus ramidus, and drawing information from the bone fragments of 35 individuals. The researchers also examined the remains of animals, seeds and pollen uncovered at the excavation site [that] reveal it to have been a woodland where colobus monkeys swung in trees full of swifts, doves and lovebirds, and spiral-horned antelope, elephants, shrews and early forms of peacock roamed the forest floor below [The Guardian].

That woodland habitat contrasts with the savanna where Lucy was thought to dwell, and it has big implications for our understanding of what caused hominids to rise to their feet. If the researchers are correct in thinking that Ardi walked upright as well as climbed trees, the environmental evidence would seem to strike the death knell for the “savanna hypothesis”—a long-standing notion that our ancestors first stood up in response to their move onto an open grassland environment [National Geographic News].

So how did bipedalism take off? One provocative idea rests on Ardi’s dental records. Researchers say her species lacks many typical features of chimpanzees, including large male canine teeth — a sign, say the researchers, that the ultra-aggressive social behaviors seen in chimpanzees were lost early in the human lineage. If so, male A. ramidus may have competed for female attention by bringing them food, rather than fighting each other. That could have contributed to the evolution of pair-bonding behavior [Wired.com]. Some anthropologists believe that early hominids may have switched from a four-limbed gait to a two-legged stride so that the males could more easily bring home the bacon.

Related Content:
The Loom: Ardipithecus: We Meet At Last has much more on the findings
80beats: Did a Strangely Human-Like Primate Give Rise to Monkeys, Apes, and Us?
80beats: No Tarzans Here: Earliest Humans Quickly Lost Their Ape-Like Climbing Abilities
DISCOVER: The 2% Difference examines what sets us apart from chimpanzees

Image: J.H. Matternes

First Europeans Mastered the “Stone Age Swiss Army Knife” Early On

Eliza Strickland — Thu, 03 Sep 2009 18:58:12 +0000

Stone Age Europeans may not have been the last to hear about those nifty gadgets called stone axes, after all. New research at two sites in southern Spain indicates that the people there were fashioning hand axes as early as 900,000 years ago, far earlier than previously believed.

Hand axes have sometimes been called the Swiss Army knives of the Stone Age world. They vary in shape and size, but most are at least roughly symmetrical, with one pointed and one rounded edge. Hand axes were very handy for butchering animals and cutting the stalks of tough plants [ScienceNOW Daily News]. Previously, archaeologists believed that the first Europeans lagged behind people living in Africa, the Middle East, and Asia in their tool-making capabilities. Axes dating back to 1.5 million years ago have been found in Africa, while the earliest axes found in Europe were thought to be no more than 500,000 years old.

The new study, published in Nature, suggests that vital information about tool-making traveled relatively quickly through the ancient world. The new time frame was determined through a process called paleomagnetic dating, which takes advantage of the fact that the Earth’s magnetic field has reversed itself often on geological timescales. By analyzing the polarity of magnetic minerals in rock, scientists can determine when the rock formed…. At each site, the researchers took samples at regular intervals above and below the level where hand axes were found. The last complete magnetic reversal was 780,000 years ago, and both sites dated back to about this time [The New York Times]. At the two sites, the analyses indicated that the tools were at least 760,000 and 900,000 years old, respectively.

Image: Michael Walker

Stone Age Hunters Used “Pyro-Engineering” to Make Stronger Tools

Eliza Strickland — Mon, 17 Aug 2009 17:56:05 +0000

A Stone Age campsite on the coast of South Africa has revealed the earliest evidence of early humans who used fire to make better, sharper stone tools. Researchers had been surprised to find spear points and other stone implements made of silcrete, a crumbly rock that doesn’t respond well to the flaking, chipping process that early tool-makers employed. But lead researcher Kyle Brown noticed that many of the ancient blades bore the same glossy sheen as North American tools created from heat-treated stone. “It seemed like the most logical thing to do was take some of this poor quality material that we’ve been collecting and put it under a fire and see what happens,” he says [New Scientist].

Brown buried silcrete stones in a fire pit and kept a roaring fire going for up to 10 hours at a time. When the blaze eventually died down and the rocks had cooled, they looked different, with a new reddish sheen. They also had different physical properties. “The stone becomes harder and stiffer,” Brown says. “It basically becomes more brittle, which is great if you are breaking something [and] you want it to break more easily” [NPR News]. The flakes from the treated stones were also sharper than those created from untreated silcrete.

The study, published in Science, pushes back the onset of “pyro-engineering.” Previously, scientists had believed the first fire-hardened tools were created 25,000 years ago in Europe, but the treated blades found in South Africa date from about 70,000 years ago. Researchers say the technique illuminates the transition between using fire to cook food (which early humans probably figured out about 800,000 years ago), and its more sophisticated use in pottery making and metal working. Brown says that by “72,000 years ago, people are doing more than just using fires for cooking, heat, light or protection…. I think heating stones is the dawn of human engineering” [BBC News].

Heat treatment of stones for toolmaking occurred in several steps that required complex thinking abilities, the researchers assert. Toolmakers buried selected pieces of stone beneath a fire at a campsite or workshop, probably for a day or more, they suspect. Stones were then removed and worked into shape as cutting tools [Science News]. The complicated process shows that the toolmakers had mastered advance planning, and Brown goes so far as to suggest that they must have had language as well, so that instructions could be passed down from generation to generation.

Image: Science / AAAS. A replicated tool with blades made from heated silcrete.

Egyptian Archers Dyed Their Quivers 4,000 Years Ago

Allison Bond — Tue, 11 Aug 2009 17:04:02 +0000

By using a newly refined technique to analyze tiny bits of red pigment from an ancient Egyptian quiver, a researcher has found that a dye known as madder was used 4,000 years ago. Until now, the oldest relic containing madder dated to about 1,200 B.C., according to a study published in the journal Proceedings of the National Academy of Sciences.

Analyzing ancient pigments is difficult because often not very much pigment remains on a relic, while at the same time, removing a large chunk of the dye for analysis would destroy the object. In this study, however, the researcher was able to analyze the dye without damaging the relic by refining a technique called Raman spectroscopy, which relies on the scattering of light to study materials. That process is not generally suitable for studying madder or some other dyes, but Leona enhanced the result using tiny metal particles that could amplify the findings and detect even very low levels of chemicals [AP]. The quiver dates back to 2124 to 1981 B.C. and is about 700 years older than any previous madder remnants.

Knowing which dyes were used, and when, can provide clues as to the trade and other practices of the era. For example, this pigment required knowledge of the complex chemistry necessary to extract a plant pigment and convert it into a dye. In addition, chemical profiles of colored material can tell a detailed story about when, where, how, and sometimes even by whom a piece of art was made…. “They correspond to major industries, commerce and technology,” [author Marco Leona] says of the dye advances. The organic pigments can also be studied to identify forgeries and match similar works of art [Scientific American].

Image courtesy of PNAS

Where Did Dogs First Become Man’s Best Friend?

Eliza Strickland — Tue, 04 Aug 2009 14:25:44 +0000

Scientists trying to determine where dogs were first domesticated have been sent back to the drawing board by a new study. Back in 2002, researchers sampled DNA from dogs around the world, and determined that dogs in East Asia had the most genetic diversity, suggesting that the species originated there and that dogs in that region have had the longest time to evolve. But the new study suggests that those earlier results were skewed, because DNA sampling of African street dogs has revealed equal genetic diversity.

The earlier findings may have been thrown off because the large-scale study included both purebred dogs, whose evolution has been closely guided by human hands, and street dogs, who have bred more autonomously and randomly, and who therefore show more genetic diversity. But the 2002 researchers drew DNA from different types of dogs in different regions. Says Adam Boyko, lead researcher of the new study: “I think it means that the conclusion that was drawn before might have been premature. It’s a consequence of having a lot of street dogs from East Asia that were sampled, compared to elsewhere” [BBC News].

The new findings don’t cast doubt on the main premise of dog domestication: that dogs evolved from the gray wolves that were once common across Europe and Asia. Boyko notes that the study also does not mean domestic dogs might have originated in Africa. “We know Africa cannot be where dogs were domesticated, because there are no gray wolves there,” Boyko said. But the findings call into question the previous proof that dogs were first domesticated in East Asia [National Geographic News]. While the domestication could have occurred anywhere in Eurasia where wolves and humans coexisted, the researchers suggest the Middle East as one likely spot.

The study, published in the Proceedings of the National Academy of Sciences, focused on the genetic diversity of African village dogs … because Adam Boyko’s co-authors, his brother and sister-in-law, were travelling in Africa on honeymoon. They collected all the blood samples from the African dogs [BBC News]. To find the ultimate point of origin for domesticated dogs, the researchers hope to conduct genome-wide scans of stray dogs across the world.

Image: flickr / Casey J.

Pattern of Ripening Crops Reveals a Buried Roman Metropolis

Eliza Strickland — Fri, 31 Jul 2009 14:27:36 +0000

An ancient Roman city that was the predecessor of Venice has been rediscovered beneath croplands near the Venetian lagoon using sophisticated aerial imagery and some clever analysis. Researchers say they’ve found the harbor city of Altinum, which was once one of the richest cities of the Roman empire. But terrified by the impending invasion of the fearsome Germanic Emperor Attila the Hun, its inhabitants cut their losses and fled in AD452, leaving behind a ghost town of theatres, temples and basilicas [Times Online].

Many of the city’s ancient buildings were dismantled and the stones were carted away in the Middle Ages. The remaining foundations sunk back into the marsh, which was drained and turned into agricultural land in the 19th century. The new study, published in Science, is a result of aerial images taken in unusually dry summer of 2007, when the crops were suffering from drought. When the visible light and near-infrared images were processed to tease out subtle variations in plant water stress, a buried metropolis emerged. The researchers discovered that the crops planted on the land were in different stages of ripening, thanks to differences in the amount of water in the soil [ScienceNOW Daily News].

Lighter crops traced the outlines of buildings–including a basilica, an amphitheater, a forum, and what may have been temples–buried at least 40 centimeters below the surface. To the south of the city center runs a wide strip of riper crops. They were growing above what clearly used to be a canal, an indication that Venice’s Roman forebears were already incorporating waterways into their urban fabric [ScienceNOW Daily News]. The canal connects to the lagoon and cuts through the city, and was probably used to transport foreign goods from the harbor to the inland cities of Verona and Milan.

Researchers say that this archaeological find is particularly valuable because the city was never built over. “It’s extremely unusual for a town to go out of use like this and that is what makes it absolutely invaluable for achaeologists. It gives a full profile of what the town looked like without the imposition of modern infrastructure,” said Dr Neil Christie, a specialist in the Roman empire [Times Online].

Image: Science / AAAS

Global Warming May Have Helped Make the Incas Mighty

Allison Bond — Tue, 28 Jul 2009 21:28:29 +0000

The ancient civilization known as the Incan empire, which at its peak reached a population of 8 million people spread throughout South America, may owe its success at least in part to a warming climate, according to a study in the journal Climate of the Past. A rise in temperatures would have melted glaciers and allowed crops to grow further into the Andes mountains, fostering agricultural growth.

The study found that between 1100 and 1533 AD, temperatures increased several degrees, making it possible for the Incas to use new mountain land for agriculture. It also expanded the swath of land the empire occupied which, at its peak, spanned from the middle of Chile to the border shared by Ecuador and Colombia. This climate information came from an analysis of deeply buried sediment samples in the region the Incans once occupied. The researchers examined pollen and seeds buried in layers of mud on the floor of Lake Marcacocha in the Cuzco region of the Peruvian Andes. Similar to the rings in the trunk of a tree, each layer of sediment represents a fixed period of time. In the case of Lake Marcacocha, the researchers were able to analyze a 1,200-year-old sediment record [Discovery News].

The scientists noted the appearance for the first time of a range of trees and crops at the lake, which is 11,000 ft above sea level, over the critical period, corresponding to a tree line edging upwards [Times Online]. The alder trees that researchers found evidence of would have prevented erosion and fertilized the soil, which would have made maize and potato cultivation more efficient. Researchers think the Incas took advantage of the more temperate climate on the mountain slopes by carving terraces into the mountainsides and develop[ing] a complex system of canals to irrigate the land [Times Online], as gradually melting glaciers provided a steady source of water for the crops. The scientists’ analysis also revealed evidence of a drought around 880 AD, which may have caused the collapse of Incas’ predecessors, an empire known as the Wari.

Today, global warming has an exaggerated effect on high-altitude plants and animals, such as the now-endangered pika, and plants that have relocated to higher altitudes in pursuit of a cooler climate. There have been other changes as well: Peru’s capital continues to get much of its water from glaciers, but they are predicted to dry up within the next two decades due to climate change. Additionally, the terraces that previously trapped water for agriculture have fallen into disuse, and the predominant tree in the region is the eucalyptus, which saps what water remains in the soil and deposits resins that poison other plant life. [Lead author Alex] Chepstow-Lusty called for removal of the eucalyptus tree and a massive reforestation effort with alder or similar trees to replenish the soil, as well as repair of the derelict irrigation systems so they can once more support agriculture [Los Angeles Times]. Other experts, however, say these measures are too drastic to take before further research is done to confirm the study’s findings.

Image: flickr / kudumomo

Did Spear-Throwing Humans Kill Neanderthals?

Allison Bond — Thu, 23 Jul 2009 20:09:20 +0000

Analysis of a Neanderthal skeleton known as Shanidar 3 found in the late 1950s shows that the he likely died from injuries incurred by a thrown spear, which scientists speculate was thrown by a modern human, according to a study published in the Journal of Human Evolution.

Although a nicked rib on his left side provided a hint as to what killed Shanidar 3, scientists remained stumped on the details for decades. To find a probable cause of death for the Neanderthal, the researchers used a specially-designed crossbow to fire stone-age projectiles at precise velocities at pig carcasses…. At kinetic energies consistent with a thrown spear, the pig’s rib bore damage consistent with Shanidar 3’s isolated rib puncture [Time]. Higher kinetic energies that matched a knife or spear thrust produced more massive rib damage than that sustained by Shanidar. The scientists also found that the weapon entered Shanidar’s body from about 45 degrees above his body, provided the 5-foot-6-inch Neanderthal was standing at the time.

No one knows why Neanderthals disappeared, but they did so around the time modern humans began to spread from Africa across the globe. That has led some to speculate that our ancestors played a role in Neanderthals’ extinction. In the specific case of Shanidar 3, because modern humans are thought to have developed projectile hunting weapons and Neanderthals hadn’t, the researchers deduced the probable suspect — a modern human [LiveScience]. Still, this case from the files of CSI Stone Age is far from closed. Other scientists have theorized that Neanderthals and humans not only got along, but interbred.

Although evidence of a human-Neanderthal murder remains scant, another Neanderthal skeleton dating back some 36,000 years and found in France showed signs of a scalp injury likely caused by a sharp object that may have been delivered by a modern human at the time, [lead author Steven] Churchill said. “So if the Shanidar 3 case is also a case of inter-specific violence and if Shandiar 3 overlaps in time with modern humans, we’re beginning to get a little bit of a pattern here,” Churchill said [LiveScience]. More-exact carbon dating of the remains could provide stronger evidence for Neandercide, since Shanidar 3 is estimated to have lived between 50,000 and 75,000 years ago; modern humans began to spread around 50,000 years ago.

Photo credit: Les Todd / Duke University

World’s Oldest Flute Shows First Europeans Were a Musical Bunch

Allison Bond — Wed, 24 Jun 2009 21:44:09 +0000

A 35,000-year-old flute made of vulture bone found in a cave in southwestern Germany is the world’s oldest known musical instrument. The artifact suggests music may have been one advantage our ancestors had over their cousins, the now-extinct Neanderthals, according to a report published in the journal Nature.

The five-holed flute, which is fully intact and made from a griffon vulture’s radius bone, was discovered with fragments of other flutes crafted out of mammoth ivory. The bird-bone instrument was found in a region in which similar instruments have popped up lately, says lead author Nicholas Conard, but this flute is “by far the most complete of the musical instruments so far recovered from the caves.” … Until now the artifacts appeared to be too rare and not as precisely dated to support wider interpretations of the early rise of music [The New York Times]. To make sure the newly discovered instruments were dated correctly, samples were tested independently and using different methods at facilities in England and Germany. Both found the bone to be at least 35,000 years old, during the Modern Paleolithic era.

The ancient flute give archaeologists a glimpse into a population that was apparently already beginning to form its own culture and traditions. The flutes show that the human society of the time was becoming modern, [comments functional morphologist Jeffrey Laitman]. They were not simply devoting their lives to finding food, he said. The flutes “are telling us about intricate and delicate communication, bonding, social events that are going on” [HealthDay News]. Conard admits it’s not definitively proven that the flutes were made by Homo sapiens, not Neanderthals. Still, he says that the presence of other artistic artifacts near the instruments, such as a busty ivory figurine, mean it’s highly unlikely Neanderthals crafted the flute.

Early humans’ budding culture might have helped them survive while the Neanderthals, which left no concrete evidence of music-making, mysteriously died off. The ancient flutes are evidence for an early musical tradition that likely helped modern humans communicate and form tighter social bonds…. Music may therefore have been important to maintaining and strengthening Stone Age social networks among modern humans, allowing for greater societal organization and strategizing, said Conard [National Geographic News]. The bird-bone flute probably produced a range of harmonic tones similar to modern flute, according to a specialist in ancient music, who reproduced another Stone Age flute made of ivory to see what the original might have sounded like.