Tag Archives: Anthropology

People in the Philippines are the most Denisovan in the world

Genetic analysis has found clear traces that humans and Denisovans interbred in the past. The Philippine ethnic group known as the Ayta Magbukon has the highest level of Denisovan ancestry in the world.

The Negritos group in the Philippines comprises some 25 different ethnic groups, scattered throughout the Andaman archipelago in South-East Asia. They were once considered to be a single population, but the more researchers looked into it, the more they found that Negritos are actually very diverse.

In the new study, Maximilian Larena of Uppsala University and colleagues set out to establish the demographic history of the Philippines. Their project involved indigenous cultural communities, local universities, as well as official and non-governmental organizations from the area. With everyone working together, they were able to analyze 2.3 million genotypes from 118 ethnic groups in the Philippines — including the diverse Negrito populations.

The results were particularly intriguing for a population called the Ayta Magbukon, which still occupy vast swaths of their ancestral land and continue to coexist with the lowland population surrounding them. The Ayta Magbukon seem to possess the highest level of Denisovan ancestry in the world.

“We made this observation despite the fact that Philippine Negritos were recently admixed with East Asian-related groups—who carry little Denisovan ancestry, and which consequently diluted their levels of Denisovan ancestry,” said Larena “If we account for and masked away the East Asian-related ancestry in Philippine Negritos, their Denisovan ancestry can be up to 46 percent greater than that of Australians and Papuans.”

This finding, along with the recent discovery of a small-bodied hominin called Homo luzonensis, suggests that multiple hominin species inhabited the Philippines prior to the arrival of modern humans — and these groups likely interbred multiple times.

The Denisovans are a mysterious group of hominins identified in 2010 based on mitochondrial DNA (mtDNA) extracted from a juvenile female finger bone from the Siberian Denisova Cave. Although researchers haven’t found numerous traces of DNA, they’ve discovered traces of their DNA in modern populations. Apparently, this group in the Philippines has the highest percentage of Denisovan DNA in the world — at least that we’ve found so far.

“This admixture led to variable levels of Denisovan ancestry in the genomes of Philippine Negritos and Papuans,” co-author Mattias Jakobsson said. “In Island Southeast Asia, Philippine Negritos later admixed with East Asian migrants who possess little Denisovan ancestry, which subsequently diluted their archaic ancestry. Some groups, though, such as the Ayta Magbukon, minimally admixed with the more recent incoming migrants. For this reason, the Ayta Magbukon retained most of their inherited archaic tracts and were left with the highest level of Denisovan ancestry in the world.”

Researchers hope to sequence more genomes and better understand “how the inherited archaic tracts influenced our biology and how it contributed to our adaptation as a species,” Larena concludes.

Journal Reference: “Philippine Ayta possess the highest level of Denisovan ancestry in the world” 

Humans started growing cannabis 12,000 years ago — for food, fibers, and probably to get high

A new study traced back the origin of cannabis agriculture to nearly 12,000 years ago in East Asia. During this time cannabis was likely a multipurpose crop — it was only 4,000 years ago that farmers started growing different strains for either fiber or drug production.

Cannabis landraces in Qinghai province, central China. Credit: Guangpeng Ren.

Although it’s largely understudied due to legal reasons, cannabis is one of the first plants to be domesticated by humans. Archaeological studies have found traces of cannabis in various different cultures across the centuries, but when and where exactly was cannabis domesticated was still unclear.

Many botanists believed the plant emerged in central Asia, but a new study shows that east Asia (including parts of China) is the origin of domesticated cannabis.

A research team was led by Luca Fumagalli of the University of Lausanne and involved scientists from Britain, China, India, Pakistan, Qatar, and Switzerland. The researchers compared and analyzed 110 whole genomes of different plants, ranging from wild-growing feral plants and landraces to historical cultivars and modern hybrids.

They concluded that the ancestral domestication of cannabis plants occurred some 12,000 years ago, during a period called the Neolithic, and that the plants likely had multiple uses.

“We show that cannabis sativa was first domesticated in early Neolithic times in East Asia and that all current hemp and drug cultivars diverged from an ancestral gene pool currently represented by feral plants and landraces in China,” the study reads.

“Our genomic dating suggests that early domesticated ancestors of hemp and drug types diverged from Basal cannabis [around 12,000 years ago] indicating that the species had already been domesticated by early Neolithic times”, the study adds. The results go against a popular theory regarding the plant’s origin, the researchers add.

“Contrary to a widely-accepted view, which associates cannabis with a Central Asian center of crop domestication, our results are consistent with a single domestication origin of cannabis sativa in East Asia, in line with early archaeological evidence.”

When a study can land you in jail

Cannabis grown for drugs. Image credits: Esteban Lopez.

It’s hard to study cannabis, regardless of what your reasons are. You can’t just go around picking or buying plants because the odds are that’ll get you in trouble. To make matters even more difficult, if you want to see where a domesticated plant originated from, you have to collect samples from different parts of the world — which is even more likely to get you in trouble.

So for decades, researchers looked at indirect evidence. Most cannabis strains appear to be from Central Asia, and several cultures of that region have used cannabis for thousands of years, so that seems like a likely place of origin. It’s a good guess, but not exactly true.

Cannabis grows pretty much everywhere — that’s why it’s called “weed” — and just because people in Central Asia were quick to adopt the plant doesn’t necessarily mean they were the first ones to grow it.

After crossing legal and logistic hurdles, Fumagalli was able to gather around 80 different types of cannabis plants, either cultivated by farmers or growing in the wild. They also included 30 previously sequenced genomes in the analysis.

With this, they found that the likely ancestor of modern cannabis (the initial wild plant that was domesticated) is likely extinct. However, its closest relatives survive in parts of northwestern China. This fits very well with existing archaeological evidence, which shows evidence of hemp cord markings some 12,000 years ago. In particular, it seems to fit with a 2016 study by other scientists that said that the earliest cannabis records were mostly from China and Japan.

The early domestication of cannabis in the Neolithic could be a big deal. Cannabis isn’t exactly a food crop. You can indeed use it to get oil, and the seeds can be consumed but its main use is for fibers and for intoxication. Usually, when archaeologists look at a population domesticating a crop, they naturally think of food as a priority — but this would suggest that Neolithic folk also had, uhm, other priorities. Or simply, cannabis was a multi-purpose crop.

Diversifying crops

The team also identified the genetic changes that farmers brought over the centuries through selective breeding. They found that some 4,000 years ago, farmers started to focus on either plants that would produce fibers, or on those better suited for producing drugs.

For instance, hemp strains bred for fiber production have mutations that inhibit branching, which makes them grow taller and produce more fibers. Meanwhile, strains bred for drug production, have mutations that encourage branching and reduce vertical growth. This results in shorter plants that produce more flowers. In addition, plants grown for drug productions also have mutations that boost the production of tetrahydrocannabinol (THC).

For millennia, hemp (the cannabis grown for fibers) has been an important crop. Clothes, ropes, and various other products used hemp fibers, but the emergence of modern metalworking and modern synthetic fibers (such as nylon) led to its downfall, and the once-popular plant became all but forgotten. Until recently.

A modern cannabis greenhouse. Image credits: Richard T.

Recently, we’ve seen a resurgence in the interest in cannabis, for sustainable fiber production as well as medicinal and recreational purposes. With more and more countries decriminalizing the possession and growth of cannabis, the plant may be making a comeback — and for researchers looking to study its origin, that’s great news.

While this study offers an unprecedented view into the evolutionary history of cannabis, it’s still a relatively small sample size. Finding wild samples is hard — and feral samples you find today aren’t really wild, they’re just grown varieties that escaped and are now feral. Furthermore, even gaining access to cultivars can be difficult.

Maybe, as society becomes more inclined to consider cannabis, researchers can gain access to more resources about it as well. By studying its genomic history, scientists can also provide valuable insights into the desired functional properties of plants, helping growers develop better varieties both for medicine and for other uses.

The study has been published in Science Advances.

Scientists find 1.4 million-year-old hand axe made out of hippo femur

This 1.4-million-year-old hand axe is made out of a hippo’s thigh bone. Credit: Berhane Asfaw, University of Tokyo.

Hand axes are some of the most versatile tools humans have ever invented. You can use it to chop wood for a fireplace, butcher freshly caught game, defend against predators and other humans, or build other tools with it.

It’s no wonder then that hand axes are also the most common artifacts archaeologists and anthropologists have found, the earliest dating between one and two million years ago.

Prehistoric hand axes are typically made from stone, but researchers doing fieldwork at the Konso Formation in southern Ethiopia found one that was made out of a large chunk of bone. Turns out that the bone is actually the femur of an ancient hippotamus.

The Konso hand axe is only the second such tool completely made out of bone. Judging from the sediments from which the artifact was unearthed, the femur hand axe is around 1.4 million years old.

In all likelihood, this timeline suggests that the tool was manufactured by Homo erectusthe first hominin to have fully walked upright. They also shared many other features with modern humans, which enabled them to be quite successful, spreading from Africa across Europe and Asia.

An intelligent and skilled toolmaker

Forensic reconstruction of an adult female Homo erectus. Credit: Wikimedia Commons.

Homo erectus had little body hair, so it was able to shed heat and be active throughout the day. The appearance of the vestibulocochlear apparatus — a part of the inner ear involved in balance and movement present in modern humans — allowed H. erectus to see distant targets well.

These adaptations may have heralded a change from scavenging to hunting in our species’ lineage. This is further evidenced by the hominin’s smaller gut and teeth relative to its predecessors, which suggest it had a better diet. Bone protein released during cooking suggests that H. erectus also knew how to make a fire or at least use naturally-occurring fires.

This hominin grew tall and had long legs, making it a completely terrestrial creature. It may have used a proto-language, as indicated by the vertebrae fossils of Homo erectus georgicus, a sub-species of Homo erectus.

Like the familiar stone hand axes, the Konso was likely fashioned in the same way, by chipping bits off of the femur bone until the edge became sharp. The axe is about 13 centimeters long and has an oval shape, according to the University of Tokyo paleoanthropologist Gen Suwa, who led the new study along with his colleagues from Japan, Ethiopia, and Hong Kong.

“This bone handaxe shows that at Konso, not only in lithic technology, but also in bone modification, Homo erectus individuals were sufficiently skilled to make and use a durable cutting edge,” the scientists said.

Research conducted previously found that ancient hominins like H. erectus manufactured such hand axes using a single sharp blow to create a new tool edge. This edge would then be honed through repeated chipping with a bone or stone hammer. As many as 44 secondary flake scars were identified by the researchers, which ranged in size from 3 cm to less than 1 cm.

“Both the distribution pattern of flake scars and the high frequency of cone fractures are strong indicators of deliberate flaking,” the researchers wrote in their study published in PNAS.

The axe was likely used for butchering animals

The Konso hand axe seen from various angles. Credit: Sano et al, PNAS.

Whoever was the toolmaker, he must have been quite skilled. There’s a reason why so few bone tools have been recovered by archeologists. Besides being less able to withstand the degradation of time, bone requires more craftsmanship to shape into a tool than stone does. The toolmaker has to find just the right bone for the job and then carefully apply proper blows and chipping so the bone doesn’t break entirely.

“The handaxe is made with substantial sophistication as evidenced by, for example, the large number of small, well-controlled cortical side removals in forming the handaxe-like shape,” the researchers said.

“The finer bifacial flaking made a relatively straight edge in a side view, which enables efficient cutting.”

The bone hand axe bears evidence of wear, suggesting it had been used. The edge is rounded in places near the tip, similar to stone tools used for butchering animals.

It’s not clear why the toolmaker would choose bone over stone, despite the latter being available in ample amounts in the area. Nevertheless, we’re grateful now that such an artifact has withstood the test of time, highlighting the intelligence of H. erectus, who may very well be a direct ancestor of our species.

“The discovery of the finely made Konso bone handaxe from 1.4 million years ago shows that refinement of flaking technology in the early Acheulean involved both stone and bone and provides additional evidence of the technological and behavioral sophistication of African Homo erectus through Acheulean times,” the authors said.

A new “ghost lineage” of humans found in Africa

Over 1,000 ceramic sherds, nearly 500,000 pieces of lithic (stone) materials, and 18 skeletons have been uncovered by archaeologists at a shelter called Shum Laka, northwest Cameroon.

The rock shelter itself is approximately 50 meters wide at its greatest point and up to 20 meters deep. New skeletons uncovered at the site could force us to reconsider our early lineage and include some “ghost” ancestors.

A 1994 photograph of the excavations that yielded the skeletons at Shum Laka.

Understanding early human evolution means going back to Africa and studying ancient populations. However, that’s not an easy thing to do. We don’t know exactly where these populations lived, and finding fossils has proven to be a daunting task.

There’s another problem: even when fossils do survive, central Africa, where many of the ancient lineages lived, is too hot and humid for DNA to survive. This means that any fossils containing viable DNA are an extremely rare find — and this is exactly why this study is so important.

A rock shelter uncovered in the grasslands of Cameroon was found to contain the bones of four children buried thousands of years ago, and these bones contain enough DNA for analysis. It’s the first time DNA this old has ever been found in the area, and it holds a lot of surprises.

For starters, the area in which it was found is intriguing. The shelter, called Shum Laka, lies where West Africa meets Southern Africa. This area was inhabited by a population called the Bantu people. The Bantu made several agricultural and metallurgical developments that allowed them to spread across the continent, leaving their genetic, linguistic, and technological mark on several other populations.

Map of the major Bantu languages (shown in purple), with the non-Bantu Southern Bantoid languages, indicated in violet (northwestern corner). The approximate position of Shum Laka is highlighted in the zoom-in cassette. Image credits: Sumu / Wikipedia.

However, the children did not belong to the Bantu group, DNA analysis revealed. Instead, the children belonged to other hunter-gatherer groups called the Baka and the Aka — groups historically known as “pygmies” (though that term is considered derogatory today).

The Baka and the Aka live hundreds of kilometers away, in the rainforests of central Africa. It was surprising to see them there, inside Bantu territory, especially as these two groups are not even closely related.

But things got even more surprising.

The DNA analysis showed that all the children were related to each other, with the degree ranging from distant cousin to something similar to a half-brother. All of them, additionally, had some DNA coming from an ancient source in West Africa — including a “long lost ghost population of modern humans that we didn’t know about before,” says population geneticist David Reich of Harvard University, leader of the study.

The finding is important in multiple ways. For starters, it suggests that the theory that Bantu people originated in this area of Central Africa and radiated across the continent is not true. It might also be possible that the Bantu also shared the shelter with these groups and they are simply not represented in the burials — but if this were the case, there would probably be some interbreeding between the groups, and this was not observed.

Secondly, the analysis suggests that there are at least four major human lineages, which date to between 200,000 and 300,000 years ago. This was never shown before, and indicates a “ghost lineage” — an ancient group for which we have no physical evidence.

The data from these genomes, combined with some additional modern samples from West Africa, suggest that an unknown group contributed to hunter-gatherers from both East and West Africa. But it doesn’t appear to have persisted to the present as a distinct population.

All of this goes to show just how crazily complex mankind’s early evolution was. There were multiple groups isolated from each other for long periods of time which then started spreading and intermingling, but we don’t know who came from where. We also have “ghost lineages” in our past, and we need to find physical evidence to better understand who these people were.

It’s all a massively intricate story, and for all the missing puzzle pieces, it’s remarkable that researchers have cobbled together so much with so little information. It will take a long time to uncover all the puzzle pieces, but it’s well worth it. After all, it’s our story.

The study has been published in Nature.

Engraved Crimean flint could point to Neanderthal symbolism

Some 35,000 years ago, a Neanderthal carved some lines into a piece of rock, immortalizing what researchers now believe to be evidence that his kind was capable of symbolic thought.

The engraved flint researchers analyzed (top) and a reconstruction (bottom). Image credits: Majkic et al., 2018.

The idea of an unthinking Neanderthal brute has long been disproven by now. We now have clear evidence that Neanderthals were just as intelligent and capable as early humans, if not more so. Now, there is growing evidence that aside from being quite capable, Neanderthals were also capable of symbolic thought — a type of abstract thinking in which symbols or images are used to represent objects, persons, and events that are not present.

In understanding this, carved stone artifacts are extremely important, offering clues on human culture and cognition, as well as abstract thinking. For instance, several sites from the Middle and Lower Paleolithic across Europe and the Middle East have yielded carved flint or chert flakes, including some remarkable findings from Neanderthal sites. But the problem is always the same: how do you determine the action that created the carvings? Was it an accidental scrape, or a purposeful engraving? If it was purposeful, was it a practical purpose, a ritual, or something completely different?

To solve these questions, Ana Majkic from the University of Bordeaux, France, and colleagues used state of the art instruments to assess the structure and patterns of the engraved ridges, developing a framework of potential causal actions.

They started out with a broad list, Majkic tells ZME Science, considering a wide range of potential sources such as marks left on a cutting board, hammer, grinding stone, or simply a way to recover the flint nodules. They also considered more specific uses, such as a way to indicate to a novice where to strike, doodling, playing some kind of game or communicating a symbolic meaning.

“Even when it is possible to demonstrate that the engravings are ancient and human made, it is often difficult to distinguish incisions resulting from functional activities such as butchery or use as a cutting board, from those produced deliberately, and even more difficult to identify the scope of the latter,” researchers write.

They carried out a microscopic analysis of the cortex (the soft outer layer of the rock) and the features themselves, moving on to a 3D reconstruction, and started ruling out possibilities. The location of the engraving and the way in which the lines were produced indicated that the rock was engraved after the flake was detached from the core, thus ruling out the causes that may have led to marking the cortex of a nodule. Although flat, the cortex was too small to use as a chopping board. The ridges also aren’t consistent with tools like hammers or axes, and so on. Step by step, they showed not only that the carvings were made with a clear intent, but also that they were made by a skilled individual. The precision with which engraving was executed also indicates very good hand-eye coordination and motor skills employed with effort, attention to detail, and an intent to frame the incise in a particular way.

Lastly, the results were consistent with the “possible representational interpretation of the object” — in other words, it’s plausible that the Neanderthal(s) who made this wanted to symbolically represent something.

“The microscopic analysis and 3D reconstruction of the grooves on the cortex of this small flint flake, demonstrate that the incisions represent a deliberate engraving made by a skilled craftsman, probably with two different points. The lines are nearly perfectly framed into the cortex, testifying of well controlled motions. This is especially the case considering the small size of the object, which makes this a difficult task,” the study continues.

“The production of the engraving required excellent neuromotor and volitional control, which implies focused attention. Evaluation of the Kiik-Koba evidence in the light of the proposed interpretative framework supports the view that the engraving was made with a representational intent,” researchers conclude.

Lastly, Majkic and her colleagues hope that the methodology can be extended to other similar artifacts. For now, evidence is piling up that Neanderthals were capable of symbolic representations, but there’s still a long way to go before that can be definitively concluded.

Journal Reference: Majkic A, d’Errico F, Stepanchuk V (2018) Assessing the significance of Palaeolithic engraved cortexes. A case study from the Mousterian site of Kiik-Koba, Crimea. https://doi.org/10.1371/journal.pone.0195049

How expressive eyebrows helped shape human evolution

Mobile, expressive eyebrows give humans the ability to express a broader range of feelings and emotions, adding more subtlety and nuance to our interpersonal relations.

Eyebrows on fleek: Model of a modern human skull next to Kabwe 1. Image credits: Paul O’Higgins, University of York.

If you think about it, Homo sapiens don’t really have much going for them as a dominant species. We’re not the strongest or most agile creatures around, and we weren’t necessarily the smartest. But, humans did shine in one particular aspect: communication. Humans established large social networks which functioned with unprecedented efficiency — and apparently, eyebrows also played a part in that.

Modern humans have smooth, vertical foreheads with communicative eyebrows. Early humans, in contrast, sported thick, bony brow ridges. Previous studies have argued that these features protected against bites or scratches, but a new study suggests that, like antlers on a stag, pronounced brow ridges were a permanent signal of dominance and aggression in our early ancestors’ times.

Ricardo Godinho and colleagues digitally recreated a fossil Homo heidelbergensis skull thought to be between 125,000 and 300,000 years old. They found that the brow ridge is much larger than what would be needed to account for the disjunction between the eye sockets and braincase, and it also does little to protect the skull when eating.

Instead, Godinho and his colleagues suggest that the brows had a social purpose, especially since similar features are used for signaling in other primates. For instance, the baboon-like mandrills have bony, colorful muzzles that signal dominance in males and reproductive status in females. Paul O’Higgins, Professor of Anatomy at the University of York, and another lead author of the study, said:

“Looking at other animals can offer interesting clues as to what the function of a prominent brow ridge may have been. In mandrills, dominant males have brightly coloured swellings on either side of their muzzles to display their status. The growth of these lumps is triggered by hormonal factors and the bones underlying them are pitted with microscopic craters – a feature that can also be seen in the brow bones of archaic hominins.”

Previous research suggests that our faces have gotten progressively smaller, over the past 100,000 years, with the process accelerating in the past 20,000 years — especially as we switched from hunter-gatherers to farmers, a process that involved less effort and less variety in the foods we ate.

As all other hominins were fading away, humans were rapidly colonizing the globe, surviving in varied, and sometimes extreme environments. This was largely owed to our complex social networks. For instance, as Dr. Penny Spikins from the Department of Archaeology at the University of York explains, we do know that prehistoric modern humans avoided inbreeding and went to stay with friends in distant locations during hard times. Eyebrows could have played a surprisingly big role, allowing humans to send elaborate social signals in an instant — eyebrows might be the communication missing puzzle piece, Spikins says.

“Eyebrow movements allow us to express complex emotions as well as perceive the emotions of others. A rapid “eyebrow flash” is a cross-cultural sign of recognition and openness to social interaction and pulling our eyebrows up at the middle is an expression of sympathy. Tiny movements of the eyebrows are also a key component to identifying trustworthiness and deception. On the flip side it has been shown that people who have had botox which limits eyebrow movement are less able to empathise and identify with the emotions of others,” Spiking adds.

“Eyebrows are the missing part of the puzzle of how modern humans managed to get on so much better with each other than other now-extinct hominins,” she concludes.

Journal ReferenceSupraorbital morphology and social dynamics in human evolution. DOI 10.1038/s41559-018-0528-0

Human bones in underwater Mexico cave dated to 13,000 years ago — thanks to a pelvis-stalagmite

In February 2012, researchers discovered a human skeleton in an underwater cave in Mexico. Their joy, however, was short-lived. Just days after photos were made public, unknown divers plundered the cave, stealing the complete skeleton and everything else they could find. They were never identified, the skeleton never located. Still, researchers managed to date a bone, based on measurements conducted on a stalagmite in the cave. The research findings have now been published in PLoS ONE.

Prehistoric human skeleton in the Chan Hol Cave near Tulúm on the Yucatán peninsula prior to looting by unknown cave divers. Picture: Tom Poole, Liquid Jungle Lab.

Settling a settlement debate

The earliest settlement in North America is still a matter of debate among anthropologists and archaeologists. The classical hypothesis is that the first migration took place 12,600 years ago through an ice-free corridor between retreating North American glaciers, over the Bering Strait which was still covered by an ice. That hypothesis is recently coming under more and more fire, with evidence from both North and South America suggesting that a migration took place earlier. However, that evidence is mostly hearths and artifacts — it’s extremely rare to find any human skeletons older than 10,000 years in the Americas. This is why this particular finding might be so important.

“The bones from the Chan Hol Cave near the city of Tulúm discovered five years ago represent one of the oldest finds of human bones on the American continent and are evidence of an unexpectedly early settlement in Southern Mexico,” says Prof. Wolfgang Stinnesbeck, who is an earth scientist at Heidelberg University.

The skeleton was found in a vast system of underwater carbonate bedrock caves filled alternatively with salt and sweet water. These caves, located near Tulúm on the Yucatán Peninsula, have proven a valuable trove for researchers. They contain archaeological, palaeontological and climatic information hidden there from the time before the flooding, which is extremely well preserved, according to Stinnesbeck.

“When my Mexican colleagues Arturo Gonzalez and Jerónimo Avilés showed me the first photos of the Chan Hol site, I immediately knew that we had something special,” says Stinnesbeck.

This is why, when the skeleton was stolen, it hurt even more. But scientists didn’t give up. They still had one bone to analyze — a pelvic bone that had since grown a stalagmite, a rock formation rising from the floor of a cave due to material deposited on the floor from ceiling drippings. Stalagmites are the floor counterpart of ceiling stalactites.

The ancient pelvis, as indicated by the orange arrow. Image credits: Wolfgang Stinnesbeck.

Left them a bone

Dating the bone was no easy feat, for all the potential it yielded. Bones this old have no more collagen, which is what is commonly used for dating bones. So instead, researchers took a different route: they dated it like a rock, not like a bone — something which was possible only thanks to the unique environment of the bone. They used the uranium, carbon, and oxygen isotopes in the bone itself and in the stalagmite that had grown through it. They then analyzed the oxygen and carbon isotope ratios, which are directly related to climate and precipitation data. This can be correlated to existing data, so the age of the stalagmite was estimated, and from it, the age of the bone. Researchers say it is at least 13,000 years old, which would add another nail in the coffin of the classic settlement theory.

More evidence would likely settle this debate once and for all, since this is still an indirect dating method, and more evidence likely lies in or around the cave system. But the area is threatened by growing tourism and urbanization in the area. It’s no coincidence that the skeleton was stolen after only a few photos, and researchers fear what is to happen to the cave if it is left unprotected. Whatever evidence may lie there could be gone forever.

This study fits in neatly with previous findings from the Paisley Cave in Oregon and Monte Verde, Chile, where there is evidence of early settlements.

Journal Reference: Wolfgang Stinnesbeck et al — The earliest settlers of Mesoamerica date back to the late Pleistocene.

 

Foragers farmers fossil fuels.

Book Review: ‘Foragers, Farmers, and Fossil Fuels: How Human Values Evolve’

Foragers farmers fossil fuels.

 

“Foragers, Farmers, and Fossil Fuels: How Human Values Evolve”
By Ian Morris
Princeton University Press, 400pp | Buy on Amazon

What we consider as ‘right’ or ‘just’ isn’t set in stone — far from it. In Foragers, Farmers, and Fossil Fuels, Stanford University’s Willard Professor of Classics Ian Morris weaves together several strands of science, most notably history, anthropology, archeology, and biology, to show how our values change to meet a single overriding human need: energy.

Do you think your boss should be considered better than you in the eyes of the law? Is it ok to stab someone over an insult? Or for your country’s military to shell some other country back to the stone age just because they’re ‘the enemy’? Do leaders get their mandate from the people, from god, or is power something to be taken by force? Is it ok to own people? Should women tend to home and family only, or can they pick their own way in life?

Your answers and the answers of someone living in the stone age, the dark age, or even somebody from a Mad-Men-esque 1960’s USA wouldn’t look the same. In fact, your answers and the answers of someone else living today in a different place likely won’t be the same.

Values derive from culture

They’ll be different because a lot of disparate factors weigh in on how we think about these issues. For simplicity’s sake, we’ll bundle all of them up under the umbrella-term of ‘culture’, taken to mean “the ideas, customs, and social behavior of a particular people or society.” I know what you’ll answer in broad lines because I can take a look at Google Analytics and see that most of you come from developed, industrialized countries which (for the most part) are quite secular and have solid education systems. That makes most of you quite WEIRD — western, educated, industrialized, rich, and democratic.

As we’re all so very weird, our cultures tend to differ a bit on the surface (we speak different languages and each have our own national dessert, for example). The really deep stuff, however — the frameworks on which our cultures revolve —  these tend to align pretty well (we see equality as good, violence as being bad, to name a few). In other words, we’re a bit different but we all share a core of identical values. Kind of like Christmass time, when everybody has very similar trees but decorates them differently, WEIRD cultures are variations on the same pattern.

It’s not the only pattern out there by any means, but it’s one of the (surprisingly) few that seem to work. Drawing on his own experience of culture shock working as an anthropologist and archaeologist in non-WEIRD countries, Professor Morris mixes in a bird’s eye view of history with biology and helpings from other fields of science to show how the dominant source of energy a society draws on forces them to clump into one of three cultural patterns — hunter-gatherers, farmers (which he names Agraria), and fossil-fuel users (Industria).

Energy dictates culture

In broad lines, Morris looks at culture as a society’s way to adapt to sources of energy capture. The better adapted they become, the bigger the slice of available energy they can extract, and the better equipped they will be to displace other cultures — be them on the same developmental level or not. This process can have ramifications in seemingly unrelated ways we go about our lives.

To get an idea of how Morris attacks the issue, let’s take a very narrow look at Chapter 2, where he talks about prehistoric and current hunter-gatherer cultural patterns. Morris shows how they “share a striking set of egalitarian values,” and overall “take an extremely negative view of political and economic hierarchy, but accept fairly mild forms of gender hierarchy and recognize that there is a time and place for violence.”

This cultural pattern stems from a society which extracts energy from its surroundings without exercising any “deliberate alterations of the gene pool of harvested resources.” Since everything was harvested from the wild and there was no way to store it, there was a general expectation to share food with the group. Certain manufactured goods did have an owner, but because people had to move around to survive, accumulating wealth beyond trinkets or tools to pass on was basically impossible, and organized government was impractical. Finally, gender roles only went as far as biological constraints — men were better tailored to hunt, so they were the ones that hunted, for example. But the work of a male hunter or a female gatherer were equally important to assuring a family’s or group’s caloric needs were met — as such, society had equal expectations and provided almost the same level of freedom and the same rights for everyone, regardless of sex. There was one area, however, where foragers weren’t so egalitarian:

“Abused wives regularly walk away from their husbands without much fuss or criticism [in foraging societies],” Morris writes, something which would be unthinkable in the coming Agraria.

“Forager equalitarianism partially breaks down, though, when it comes to gender hierarchy. Social scientists continue to argue why men normally hold the upper hand in foarger societies. After all, […] biology seems to have dealt women better cards. Sperm are abundant […] and therefore cheap, while eggs are scarce […] and therefore expensive. Women ought to be able to demand all kinds of services from men in return for access to their eggs,” Morris explains in another paragraph. “To some extent, this does happen,” he adds, noting that male foragers participate “substantially more in childrearing than […] our closest genetic neighbours.”

But political or economic authority is something they can almost never demand from the males. This, Morris writes, is because “semen is not the only thing male foragers are selling.”

“Because [males] are also the main providers of violence, women need to bargain for protection; because men are the main hunters, women need to bargain for meat; and because hunting often trains men to cooperate and trust one another, individual women often find themselves negotiating with cartels of men,” he explains.

This is only a sliver of a chapter. You can expect to see this sort of in-depth commentary of how energy capture dictates the shape of societies across the span of time throughout the 400-page book. I don’t want to spoil the rest of it, since it really is an enjoyable read so I’ll give you the immensely-summed-up version:

Farmers / Agraria exercise some genetic modifications in other species (domestication), tolerate huge political, economic, and gender hierarchies, and are somewhat tolerant of violence (but less than foragers). Fossil-fuelers / Industria was made possible by an “energy bonanza,” and are very intolerant of political hierarchies, gender hierarchy, and violence, but are somewhat tolerant of economic hierarchies (less than Agrarians).

These sets of values ‘stuck’ because they maximised societies’ ability to harvest energy at each developmental level. Societies which could draw on more energy could impose themselves on others (through technology, culture, economy, warfare), eventually displacing them or making these other societies adopt the same values in an effort to compete.

Should I read it?

Definitely. Morris’ is a very Darwinian take on culture, and he links this underlying principle with cultural forms in a very pleasant style that hits the delicate balance of staying comprehensive without being boring, accessible without feeling dumbed down.

The theory is not without its shortcomings, and the book even has four chapters devoted to very smart people (University of Exter professor emeritus of classics and ancient history Richard Seaford, former Sterling Professor of History at Yale University Jonathan D. Spence, Harvard University Professor of Philosophy Christine Korsgaard, and The Handmaiden’s Tale’s own Margaret Atwood) slicing the theory and bashing it about for all its flaws. Which I very much do appreciate, as in Morris’ own words, debates “raise all kinds of questions that I would not have thought of by myself.” Questions which the author does not leave unanswered.

All in all, it’s a book I couldn’t more warmly recommend. I’ve been putting off this review for weeks now, simply because I liked it so much, I wanted to make sure I do it some tiny bit of justice. It’s the product of a lifetime’s personal experience, mixed with a vast body of research, then distilled through the hand of a gifted wordsmith. It’s a book that will help you understand how values — and with them, the world we know today — came to be, and how they evolved through time. It’ll give you a new pair of (not always rose-tinted) glasses through which to view human cultures, whether you’re in your home neighborhood or vacationing halfway across the world.

But most of all, Foragers, Farmers, and Fossil Fuels will show you that apart from a few biologically “hardwired” ones it’s the daily churn of society, not some ultimate authority or moral compass, that dictates our values — that’s a very liberating realization. It means we’re free to decide for ourselves which are important, which are not, and what we should strive for to change our society for the better. Especially now that new sources of energy are knocking at our door.

About 100,000 years ago, people with autism were championed, not shunned, and may even have shaped human evolution

A University of York study found that roughly 100,000 years ago, primitive societies weren’t shunning people with autism — in fact, they were embraced as respected specialists in their groups for their unique abilities, allowing them to play a central part in human evolution.

Characteristics associated with the autistic specter, such as attention to detail and exceptional memory skills, can be identified in cave art.
Image credits University of York.

Humans are social animals. The life we know today, with roads, grocery shops, smartphones, is only possible because generation after generation, we’ve worked together, pooling our abilities to improve our collective lives. But it hasn’t always been the case. A study now estimates that this group-oriented attitude, known as collaborative morality, emerged through a subtle evolutionary shift some 100,000 years ago. By changing the focus from a person’s characteristics to their abilities, skills, and value to the group, collaborative morality opened up a social niche for one demographic likely ostracized before — people with autism.

Rather than being left behind, the team concludes that they assumed an important role in their social groups due to their unique traits. This, in the long run, allowed them to play a major part in human development and evolution.

“We are arguing that diversity, variation between people, was probably more significant in human evolutionary success than the characteristics of one person,“ said Penny Spikins, senior lecturer in the archaeology of human origins at the University of York and lead author of the study.

Geneticists believe that autism has a long evolutionary history in humans, likely appearing before the stone age. Today, fields such as engineering, mathematics, law, and other academia attract a high rate of people with autism, most notably Asperger’s syndrome. Coping with autism even in the modern world is difficult at best. But, the team argues that the traits which push modern individuals towards these fields provided a powerful advantage for the early social groups of a hunter-gatherer society.

For example, autism is often associated with heightened visual, olfactory, and taste perception, as well as exceptional memory skills (very useful in navigating the world without GPS). Asperger’s syndrome is associated with a heightened attention to detail (recognizing different plants or animals), understanding of systems (such as the behavior of prey), and increased focusing ability.

What these people lacked in social integration, they more than made up for it by sheer group utility.

“It was diversity between people which led to human success and it is particularly important as it gives you different specialised roles,” Spikins added.

In essence, they formed society’s first specialists, filling in roles that the others couldn’t perform as well. Neurosciencenews cites the example of a 2005 study of an elderly reindeer herder with autism from Siberia who “revealed a detailed memory of the parentage, medical history and character of each one of his 2,600 animals.” His knowledge made a huge contribution to the herd’s management and survival, having a direct effect on the group’s prosperity and well-being. Despite being “more comfortable in the presence of the reindeer than humans,” he was a well-respected and important person in the group, had a wife, a son, and even grandchildren. A person with similar abilities would have likely received a similar treatment in a group of early humans.

But finding verifiable proof of autism in archaeological records has always been tricky for researchers. There is no skeletal record of the condition. There is indirect proof to be had, however, in observing how other people that differ from the norm were integrated, as well as cave art or other artifacts from which autistic behavior can be inferred.

“There has been a long-standing debate about identifying traits of autism in Upper Palaeolithic cave art,” Dr Spikins said.

“We can’t say some of it was drawn by someone with autism, but there are traits that are identifiable to someone who has autism. It was also roughly at that time that we see collaborative morality emerging.”

The authors are asking the public to help them with an online survey of cognition and art perception, which you can fill out here.

The full paper, “Are there alternative adaptive strategies to human pro-sociality? The role of collaborative morality in the emergence of personality variation and autistic traits” has been published online in the journal Time and Mind.

Ancient Alaskans feasted on salmon 12,000 years ago

At least 15 cooking hearths have been unearthed in Alaska, revealing surprising facts about the lives and diets of the Sub-Arctic hunters of the Ice Age.

In 2013 and 2014, researchers expanded the dig at Upward Sun River to study the relationship between the residential structure and the hearths. (Photo by Ben Potter)

The hearths, which have been dated to at least 11,800 years old, contain numerous salmon remains. Archaeologists believe this is the earliest evidence of salmon cooking in the New World.

Finding salmon in Alaska, even during the Ice Age, might not seem surprising, but scientists believed that Alaskan hunters mostly ate what they hunted on land – namely bison, elk, and mammoths. However, in light of this recent find, fish seems to have also been valued as a great resource.

“Our results demonstrate that salmonid and freshwater resources were more important for late Pleistocene hunter-gatherers than previously thought,” the team writes in their report on their findings, in the Proceedings of the National Academies of Science.

Modern science for ancient studies

In recent years, archaeology has greatly benefitted from technological advancements. In this particular case, they used isotopic analysis to study the charred remains found in the hearth. Judging by the presence of several isotopes, scientists can trace the origin of whatever was burned (to an extent). They can also date it. In this case, they traced it back to 11,800-year-old salmon.

“It’s quite new in the archaeology field [the technology],” said Kyungcheol Choy, the University of Alaska-Fairbanks, researcher who led the study, in a press statement. “There’s a lot in these mixtures that’s hard to detect in other ways.”

This makes it the oldest proven salmon consumption in the Western Hemisphere, but it’s not the only thing they can find through the technology. For instance, aside for the 10 hearths which contained heavy salmon residue, others contained many traces of freshwater fish and land animals, suggesting that separate pits were used for preparing different kinds of food, consistently over the course of thousands of years.

This adds greatly to our understanding of the ancient people’s lives, because in a way, modern archaeology is a lot like crime scene investigation. It’s not so much about finding new things and structures, because most of them have already been found. Instead, the focus is on understanding these people, understanding what their life was like and how they developed as population. Of course, diet plays a key role in any population’s lifestyle.

“Our findings reveal that analysis of organic residues from hearth sediments can have great utility for reconstructing dietary trends and subsistence practices among mobile hunter-gatherers, particularly in contexts where faunal remains are poorly preserved,” they write. “It’s an awesome look at how we can merge disciplines to answer a question,” Potter added in the press statement.

Journal Reference: Choy, K., Potter, B., McKinney, H., Reuther, J., Wang, S., & Wooller, M. (2016). Chemical profiling of ancient hearths reveals recurrent salmon use in Ice Age Beringia Proceedings of the National Academy of Sciences, 113 (35), 9757-9762 DOI:10.1073/pnas.1606219113

Did the earliest Americans walk on ice or cross on water? New study sparks debate

How did people get to America, and when? A new, ‘pioneering and neat’ study may have some answers.

The traditional belief of the American migration is being challenged. Image via Wikipedia.

The traditional belief of the American migration is being challenged. Image via Wikipedia.

If we want to understand human migration, it’s all about the timings. For example, if you’d ask anthropologists how the earliest people got to the Americas, they’ll likely tell you they crossed a small land bridge between Siberia and Alaska. This would mean that they crossed it towards the end of the glacial age, but before all the ice melted and submerged the bridge. This puts a fairly good time frame on the event and it’s what most scientists believed.

But recently, that belief is starting to be challenged. There is mounting evidence that the presumed ice-free corridor on which settlers arrived wasn’t walkable until much later, when the first humans had already reached the Americas. We know that those glaciers started melting 14,000–15,000 years ago, during the time of the Clovis Culture. The Clovis people were the ones to pass through the land bridge which is now underwater, settling in the lower 48 states some 13,000 years ago. But the time doesn’t fit, because there is evidence of human activity in the Americas from 15,000 years ago. This means that someone got there before the Clovis did.

Researchers believed early settlers passed through a similar Alaskan landscape. Image via Pixabay

A new study adds a lot of weight to that idea. The research analyzed the DNA of pollen, plants, and animals collected from lake sediments around the presumed land bridge, finding that the date in which it was passable was 12,600 years ago. This is millennia after the first people got to North America.

“This is a really neat and pioneering study,” says Stephen Jackson, a paleoecologist with the U.S. Geological Survey’s Southwest Climate Science Center in Tucson, Arizona, who was not involved in the work. Because this is the first study to take into account both so-called environmental DNA (eDNA) as well as more traditional types of data, he says, “we stand to learn a good deal more about how to interpret our records.” Because DNA has an electric charge, it can bind to some sediments and preserve itself for a longer time in calm lake sediments.

The DNA of a migration

The core samples they took paint a very clear picture of an environmental transition: from icy wasteland to fertile forest to the underwater environment we see today. For the first 700 years after the ice started retreating, there were almost no plant or animal remains. Then, they found evidence of animals such as woolly mammoth, bison, and jackrabbits. By about 12,400 years ago, forests of Populus trees (related to poplar trees) started to dominate, and the area was likely a fertile forest. Then, about 11,600 years ago, it changed again, becoming a boreal forest of spruce and pine trees.

This timeline may have to be rethinked. GIF via Wikipedia.

However, settlers had already reached America by then, and Jackson believes they took the coastal route. Using the numerous islands in the area as pit stops.

“The idea is that there was a land bridge a few thousand years earlier than the formation of the ice-free corridor,” he says. “That land is now covered by ocean, but there are some islands believed to be part of that route. It would be interesting to go and look for cores and try to do the same exercise there.”

It’s not the first study to suggest this. Previously, another recent study of mitochondrial DNA in northern and southern populations of bison separated by the corridor puts the walkable date at 13,000 years ago – which might be enough for the Clovis people.

“It’s a pretty subtle difference,” says Duane Froese, a geoscientist from the University of Alberta, Edmonton, in Canada, and a co-author of that study.

However, that difference could be very significant, and not everyone is convinced. This type of paleoecology DNA study is still in its infancy, but it is a very intriguing starting point.

Journal Reference: Postglacial viability and colonization in North America’s ice-free corridor. Nature (2016) doi:10.1038/nature19085

Scientists solve one of anthropology’s most famous hoaxes

In 1912, palaeontologist Arthur Smith Woodward and the amateur antiquarian Charles Dawson made a stunning announcement: they claimed they discovered a missing link in human evolution, a humanlike skull with an apelike mandible. The thing is… it was a human skull with an orangutan mandible. Dubbed the Piltdown Man, the skeleton was one of the most elaborate and damaging hoaxes in history, triggering a decade-long debate and setting countless researchers on a wrong path. Now, after more than a century, scientists believe they finally got to the bottom of this hoax.

The Hoax

A replica of the Piltdown Man skull. Photo by Mike Peel.

In the early 1900s, British naturalism was undergoing an identity crisis. After being the driving force in science for centuries, they found themselves caught up by researchers from other countries, especially Germany, where Homo heidelbergensis had just been discovered. Not wanting to be outdone, several notable naturalists developed a type of obsession with human ancestors, trying to uncover all the missing links in the anthropological puzzles.

Dawson had found remains of what he thought was a human ancestor at a place called Piltdown in East Sussex, England. He wrote to his friend Sir Arthur Smith Woodward, announcing that he had uncovered a “thick portion of a human(?) skull which will rival H. heidelbergensis in solidity”. The two presented the discovery to the Geological Society of London in 1912, speculating that the individual lived 500,000 years ago. With both human and ape-like features, it was exactly what researchers of the time were expecting to find. But as time passed and more and more intermediate fossils were found (especially in Africa), Piltdown Man lost its significance as a singular missing link.

Even so, there was a lot of debate of the Piltdown Man, with a group of anthropologists claiming it was a fake, while others supported its validity. The hoax was exposed in 1953 when Oxford University researchers used a fluorine dating technique and showed that the specimen’s bones are of different ages. After more careful analysis, it was shown that the skull was amalgamated from both human and ape bones.

But who did it?

The portrait painted by John Cooke in 1915. Back row: (left to right) F. O. Barlow, G. Elliot Smith, Charles Dawson (pointing at the skull), Arthur Smith Woodward. Front row: A. S. Underwood, Arthur Keith, W. P. Pycraft, and Sir Ray Lankester. Photo by John Cooke, via wikimedia commons.

The Hoaxer

From the start, Woodward and Dawson were the main suspects – but not the only ones. Pierre Teilhard de Chardin, a French Jesuit priest who assisted the excavation was also a suspect, as was Martin Hinton, a volunteer who worked with Smith Woodward, among others. Even Sir Arthur Conan Doyle was a suspect, because he lived close to Piltdown and had a strong interest in the case.

Finally, in an article published in Royal Society Open Science, lead author Isabelle De Groote and more than a dozen British scientists reanalyzed the Piltdown Man remains using DNA analysis, spectroscopy, and 3D reconstructions to show that there was likely a single hoaxer: Dawson.

“It now appears that the chemical data supports the abundant circumstantial evidence that Dawson was the brains behind the hoax,” says geologist Stephen Donovan of the Naturalis Biodiversity Institute in Leiden, the Netherlands, who did not participate in the current study.

The team compared computer tomography (CT) scans of the mandible and teeth to known ape specimens and showed beyond the shadow of a doubt that they originated from an orangutan. Furthermore, DNA sequencing suggested that all the teeth came from the same orangutan, De Groote suspects the forger or forgers might have obtained from a curiosities shop.

Micro-CT scans and radiographs of the Piltdown teeth and bones, showing gravel inclusions. (Figure 5 from De Groote et al., open access in Royal Society Open Science.)

The consistency of the technique used on the skull also suggests that there was a single person doing the forging, and not a group. Dawson was an amateur geologist, archaeologist, and historian, regularly attending meetings of geologists and anthropologists. He loved fossil hunting and was quite prolific at it. He also had a habit of forging, as some of his other discoveries also turned out to be fake. But perhaps more tellingly, he wanted acceptance. Several times he applied to become a member of the Royal Society, but the scientific community rejected him every single time.

But Dawson was smart, and he played the oldest trick in the book when it comes to forgery: he showed people what they wanted to see.

“Dawson really played a very clever card,” De Groote says. “With the findings coming out of Germany, and Britain wanting to be at the forefront of science, there was this sense that, ‘We must have these fossils in Britain, as well.’”

But not everyone is convinced. Francis Thackeray, a paleoanthropologist at the University of the Witwatersrand in Johannesburg, South Africa, says he “strongly suspects” Teilhard de Chardin, the Jesuit priest. He had a reputation as a prankster, and Thackeray believes the two wanted to play a joke on Woodward, and it went seriously bad from there.

The Legacy

Whatever the case may be, the Piltdown case shows exactly why we should study hoaxes. Several anthropologists were set on a wrong track, believing that the fossil was real. Most notably, it shows how easy we can jump to conclusions when they simply fit what we want to see. Although a similar forgery is unlikely today given all the modern measuring techniques, there’s still a danger of scientists being too quick to accept a hypothesis just because it suits them. Especially in anthropology, where many scientists hoard their collections and refuse to get a second opinion, this can be a major problem.

“Piltdown Man sets a good example of the need for us to take a step back and look at the evidence for what it is,” she says, “and not for whether it conforms to our preconceived ideas.”

Ancient CSI: Scientists investigate 430,000 year old Murder

Anthropologists have uncovered a 430,000 year old homo skull with fatal wounds that represents the earliest identified murder case in human history.

Researchers used a 3D model to analyze the skull’s two fractures in detail. Photo: Sala et al., PLOS ONE

The almost complete skull called Cranium 17, was discovered broken into 52 pieces and buried under a layer of clay in a cave shaft.

Scientists used modern forensic techniques and discovered that the victim was probably killed by two blows to the head, and then was tossed up against a cave shaft. They employed the help of 3D imaging to analyze the fractures up close and visualize the trajectory of each wound; they found that both wounds were likely caused by the same object.

“Furthermore,” the team adds, “the fractures show different orientations and different trajectories, implying that each fracture was caused by an independent impact.”

In other words, the victim was smacked on the head two times with the same object. It wasn’t an accident – it was an intentional murder.

“In the case of Cr-17 it is also possible to rule out the injuries as either self-inflicted or resulting from an unintentional hunting accident, mainly because the lesions involve multiple blows,” they add. “Based on the absence of cut marks, other potential postmortem manipulations (e.g., cannibalism, ritual manipulations, etc.) seem even less likely and more speculative.”

Furthermore, there seems to be a clear intention to kill.

“Given that either of the two traumatic events was likely lethal, the presence of multiple blows implies an intention to kill.”

Sima de los Huesos.

The researchers, led by Dr Nohemi Sala, from the UCM-ISCIII Centre for the Evolution and Human Behaviour in Madrid, added:

“This represents the earliest clear case of deliberate, lethal interpersonal aggression in the hominin fossil record, demonstrating that this is an ancient human behaviour.”

The bones were found in a cave called Sima de los Huesos – the “pit of bones” – in northern Spain. The Sima de los Huesos is a well known anthropological point, with numerous findings being reported there. In 2013, researchers found the oldest human DNA ever reported at the same cave.

It’s unclear whether the murderer threw the body in the shaft to get rid of the evidence, or whether the victim was buried there with a religious ceremony. Researchers are now searching for other bodies in other shafts of the cave to see if this was a common practice.

Roman Gladiators were mostly Vegetarian, Drank Sports Drinks from Bone and Ashes

Roman gladiators – some of the most feared warriors in history were mostly vegetarian, a new anthropological study has shown.

A retiarius (“net fighter”) with a trident and cast net, fighting a secutor (79 AD mosaic). Image credits: Wiki Commons.

Gladiators fought to entertain audiences in the Roman Republic and Roman Empire in violent confrontations; they fought each other, wild animals, and convicted criminals. Some gladiators were volunteers who risked not only their social standing, but also their lives, but most of them were actually slaves, schooled under harsh conditions, socially marginalized and even as they were admired for their fighting prowess, they were still despised as inferior citizens. But even as gladiators themselves were marginalized, the idea of a gladiator was immortalized in pieces of art, from commonplace objects to magnificent pieces of art.

You’d expect someone with such a brutal “profession” to have a pretty brutal diet – eating lots of meat, living for the moment, feasting as much as possible. But a new study on gladiator bones revealed that gladiators enjoyed a diet of mostly grains and meat-free meals, suggesting that even athletes relying on their strength and speed can thrive with a vegetarian diet.

The study was conducted by researchers from the Department of Forensic Medicine at the MedUni Vienna in cooperation with the Department of Anthropology at the Institute of Forensic Medicine at the University of Bern and the bones came from Ephesos (today’s Turkey), being dated at 2nd and 3rd century B.C. At the time, Ephesos was the Roman capital of Asia, with a remarkable population of over 200,000.

Image from Ephesus. People gathered in the colosseum theater to watch gladiators fight.

Contemporary accounts of gladiator life sometimes refer to the warriors as hordearii–literally, “barley men” – and there is more true to that statement than initially thought. Karl Grossschmidt, a paleo-pathologist at the Medical University of Vienna subjected bits of the bone to isotopic analysis, a technique that measures trace chemical elements such as calcium, strontium, and zinc. By checking what chemical elements their bones have, you could reverse trace what they ate – and Grossschmidt found that they ate much more vegetables than animal protein. But they didn’t do this due to a personal belief or because they weren’t allowed to eat meat. Gladiators, it seems, were pretty fat – that’s what their bones indicate anyway. They ate a lot of carbohydrates, which helped them in two ways: it gave them strength and protected them from wounds.

 “Gladiators needed subcutaneous fat,” Grossschmidt explains. “A fat cushion protects you from cut wounds and shields nerves and blood vessels in a fight.” Not only would a lean gladiator have been dead meat, he would have made for a bad show. Surface wounds “look more spectacular,” says Grossschmidt. “If I get wounded but just in the fatty layer, I can fight on,” he adds. “It doesn’t hurt much, and it looks great for the spectators.”

But this diet had a big drawback – it left gladiators with a calcium deficit. If you don’t have enough calcium in your bones, they can simply snap, or at the very least, not support your muscles properly. But here’s the kicker: the gladiator bones had “exorbitant” levels of calcium compared to the general population. So this almost certainly means one thing – in order to compensate for this deficit, they drank vile brews of charred wood or bone ash, both of which are rich in calcium.

“Plant ashes were evidently consumed to fortify the body after physical exertion and to promote better bone healing,” explains study leader Fabian Kanz from the Department of Forensic Medicine at the MedUni Vienna. “Things were similar then to what we do today — we take magnesium and calcium (in the form of effervescent tablets, for example) following physical exertion.”

The clear formula for the drink is not clear, but whatever they used, it worked. In a way, gladiators pioneered the usage of sports drinks.

 “Many athletes today have to take calcium supplements,” he says. “They knew that then, too.”

If anything, this is yet another indication of how rough the gladiator life was. Compared to most of the world, life in the Roman Empire had some obvious perks, but not for gladiators. The crowds loved them when they won, artists revered them, but in day to day life, they were outcasts who risked their life on a regular basis with little recognition outside the arena. Wounds were also quite common.

“The proportion of wounds to the skull was surprising, since all gladiatorial types but one wore helmets,” says Harvard’s Coleman. Gladiators usually fought one-on-one, with their armor and weaponry designed to give opposite advantages

The existence of the four-pointed dagger (replica pictured here) was known from inscriptions, but its function was a mystery until this crippling quadruple knee wound was identified. (Courtesy Karl Grossschmidt)

There were different classes of Roman gladiators, and a fight usually comprised of warriors from different classes. For example, an agile lightly armored helmetless retiarus with a net and trident would be pitted against a plodding murmillo wearing a massive helmet with tiny eye slits and carrying a thick, long shield. Some match-ups were more common than others. The retiarius was traditionally pitted against a secutor or, possibly on rare occasions, a murmillo. Despite significant differences in armor and weaponry, modern analysis and reconstructions showed that the different type of gladiators were balanced – no class had a decisive advantage over another class, as bone wounds of all types have shown.

Journal Reference: Sandra Lösch, Negahnaz Moghaddam, Karl Grossschmidt, Daniele U. Risser, Fabian Kanz. Stable Isotope and Trace Element Studies on Gladiators and Contemporary Romans from Ephesus (Turkey, 2nd and 3rd Ct. AD) – Implications for Differences in Diet. PLoS ONE, October 15, 2014 DOI: 10.1371/journal.pone.0110489

The hobbits may not be real – Flores bones show features of Down syndrome, not new species

In 2004, anthropologists and archaeologists working in Indonesia uncovered what was named “the biggest anthropological finding for 100 years” – fragmentary skeletal remains from the island of Flores were uncovered, appearing to be a new species: Homo floresiensis. But now, new research challenges that find, claiming that the uncovered skeletons were in fact just an abnormal human, most consistent with Down syndrome.

Reconstruction of “the Hobbit”

We’ve written several articles describing studies on Homo floresiensis – in 2007, an international team of researchers led by the Smithsonian Institution described it as a 3-foot-tall, 18,000-year-old hominin skeleton with no chin, and less than one year later, Professor Lee Berger of the University of the Witwatersrand in Johannesburg, South Africa claimed that it was not a new species, but rather an already known one, deformed through unhealthy nutrition or genetic defects. The scientific community remained torn between two camps: those who believed it was a new species, and those who believed it was just an aberration.

Now, a new study by Robert B. Eckhardt, professor of developmental genetics and evolution at Penn State, Maciej Henneberg, professor of anatomy and pathology at the University of Adelaide, and Kenneth Hsü, a Chinese geologist and paleoclimatologist, suggests that the single specimen (known as LB1) on which the new designation depend does not represent a new species. Instead, they propose a genetic malformation – most likely Down syndrome.

“The skeletal sample from Liang Bua cave contains fragmentary remains of several individuals,” Eckhardt said. “LB1 has the only skull and thigh bones in the entire sample.”

This figure compares the skull of LB1 to that of Liang Momer E, another skull from Flores, dated in the range of 3,000 to 5,000 years ago. Credit: © Photograph of Liang Momer

They also claim some wrong measurements were made when the skull was analyzed initially. The original figures for cranial volume and stature are underestimates, “markedly lower than any later attempts to confirm them.” Eckhardt, Henneberg, and other researchers have consistently found a cranial volume of about 430 milliliters (26.2 cubic inches). The original figure was 380 milliliters (23.2 cubic inches).

“The difference is significant, and the revised figure falls in the range predicted for a modern human with Down syndrome from the same geographic region,” Eckhardt said.

The bottom line is, it’s borderline impossible to prove that the skull belongs to a new species or if it is a genetic aberration. There are some indications that it would be a new species, and, as this team found, that it is not something new, but rather a human suffering from Down syndrome.

“When we first saw these bones, several of us immediately spotted a developmental disturbance,” said Eckhardt, “but we did not assign a specific diagnosis because the bones were so fragmentary. Over the years, several lines of evidence have converged on Down syndrome.”

But extraordinary claims require extraordinary evidence, and one skull and spread out bones are, in my opinion, not enough to fully justify the existence of Homo floresiensis.

Transition to civilization led to drop in testosterone

A composite image shows the facial differences between an ancient modern human with heavy brows and a large upper face and the more recent modern human who has rounder features and a much less prominent brow. The prominence of these features can be directly traced to the influence of the hormone testosterone. Photo Credit: Robert Cieri, University of Utah

According to a new study published in Current Anthropology, our transition into modern civilization has probably coincided with a drop in testosterone. It’s very likely (though not entirely proven) that it was the transition to civilization that precipitated the drop.

University of Utah biology graduate student Robert Cieri analyzed 1,400 ancient and modern human skulls, showing that some 50.000 years ago, when human civilization was starting to be developed, a drop in testosterone also came into place. Skull shape and testosterone levels can be associated, and the decrease in testosterone can be “mapped” by changing skull anatomy.

“Humans are uniquely able to communicate complex thoughts and cooperate even with strangers,” Cieri says. “New research on fossilized Stone Age humans from Europe, Africa and the Near East suggests these traits are linked, developed around 50,000 years ago, and were a driving force behind the development of complex culture.”

It is currently accepted that modern humans, Homo sapiens, appeared about 200.000 years ago, but evidence of civilization, such as symbolic or cultural artifacts and modern tools were only found from 50.000 years ago – about the time when their faces started to become more feminine.

“Human fossils from after modern behavior became common have more feminine faces, and differences between the younger and older fossils are similar to those between faces of people with higher and lower testosterone levels living today,” Cieri says.

It is important to note that lower testosterone is associated with tolerance and cooperation in bonobos and chimpanzees, and with less aggression in humans. It seems very plausible that as humans started to group up in larger and more interconnected settlements, they needed to find less violent ways to sort out their problems – and in the long run, the non-violent path won. This may be the cause, perpetuated by natural selection, or there might be something else involved

“Whatever the cause, reduced testosterone levels enabled increasingly social people to better learn from and cooperate with each other, allowing the acceleration of cultural and technological innovation that is the hallmark of modern human success,” Cieri says.

Oldest most complete skeleton found in the New World

In what is quite an exciting study, a mixed team of researchers and cave divers announced the discovery of a near-complete early American human skeleton with an intact cranium and preserved DNA.

Credit: Paul Nicklen/National Geographic.

Over 40 meters (130 feet) below sea level, in the Hoyo Negro area in Mexico’s Yucatan Peninsula, there lies an intricate cave system which was once above the sea. There, the divers found not only the bones from a teenage female, but also bones from extinct animals.

“These discoveries are extremely significant,” said Pilar Luna, INAH’s director of underwater archaeology. “Not only do they shed light on the origins of modern Americans, they clearly demonstrate the paleontological potential of the Yucatán Peninsula and the importance of conserving Mexico’s unique heritage.”

Indeed, the discoveries are significant on many levels. First of all, finding paleontological and anthropological remains in underwater caves is always quite interesting – definitely not something you do every day. Second of all, this is the first time researchers have been able to match a skeleton with an early American (or Paleoamerican) skull and facial characteristics with DNA linked to the hunter-gatherers which inhabited Asia some 20.000 years ago (they started to move towards the Americas some 17.000 years ago). This is also one of the oldest skeletons ever found in the Americas, and it is clearly the most complete skeleton older than 12,000 years, including preserved DNA and almost all the body parts

According to the paper’s lead author, James Chatters of Applied Paleoscience:

“This expedition produced some of the most compelling evidence to date of a link between Paleoamericans, the first people to inhabit the Americas after the most recent ice age, and modern Native Americans. What this suggests is that the differences between the two are the result of in situ evolution rather than separate migrations from distinct Old World homelands.”

The conditions in which the findings were made were extremely difficult, which is why archaeologists and anthropologists had to collaborate with professional divers in what is a laudable multidisciplinary work. The effort made by the divers is complex and difficult as the one made by researchers.

Alberto Nava with Bay Area Underwater Explorers explains:

“We had no idea what we might find when we initially entered the cave, which is the allure of cave diving,” said Nava. “Needless to say, I am incredibly proud to be part of the efforts to share Hoyo Negro’s story with the world.”

 

Skull suggests three hominid species were just one

A new, controversial analysis of a skull suggests that Homo habilis, Homo rudolfensis and Homo erectus were in fact the same species, something which would force scientists rewrite a big page of anthropology.

skull

Researchers compared the anatomical features of the of a 1.8-million-year-old fossil skull with those of four other skulls from the same excavation site at Dmanisi, Georgia; the skull, informally named “Skull 5” is “the most complete skull of an adult from this date”. It’s very interesting to observe the differences between all the skulls found in the same place, from the same era:

“The Dmanisi skulls look quite different from one another”, Zollikofer says, “so it’s tempting to publish them as different species. Yet we know that these individuals came from the same location and the same geological time, so they could, in principle, represent a single population of a single species.”

Taking that theory and testing it with existing data, the statistics seem to add up.For example, the volume of skull 5 is only about 75% that of the largest skull unearthed at the Dmanisi site — a disparity that may seem large but that falls within the variation seen among modern humans and within chimpanzees. The variation also seems to fit within the range of previous findings from the same era.

“Like so many finds, [the skull] adds to what we know, but does not necessarily clarify or simplify things,” says Robert Foley, a paleoanthropologist at the University of Cambridge, UK. Nevertheless, he notes, the results of the new analysis must change the way scientists think about the nature and magnitude of anatomical variation in early Homo.

If the three species were in fact just one, then H. habilis and H. ruldofensis would be subsumed into H. erectus – but there’s a lot of criticism aimed at that idea. First of all, cramming the three species which inhabited an area (at least) from Africa to Indonesia seems a little far fetched. Fred Spoor, a palaeontologist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany is not convinced by this new theory. He believes that the statistical analysis used to study cranial differences are not relevant, and instead, researchers should have analysed pecific anatomical traits, such as the height of the braincase or the diameter of the eye socket, which are the most common characteristics used to frame species.

Via Nature.

“Adam” figure of all men is 340.000 years old

You may understand that all people are different, but it takes a lot of genetics to understand just how different humans really are. Albert Perry for example has something spectacular in his genome: his Y chromosome is so distinct, so easily identifiable that it basically revealed new information about our species. Working their way around this chromosome, researchers were able to track down traces of the last common male ancestor down the paternal line of our species. They found that this goes back to 340.000 years old; let’s get this straight: they found that this paternal line, the “X grandfather” of humans lived 340.000 ago – twice more than previously believed.

The Y chromosome is dwarfed by the X chromosome as can be seen in this image - but only in size.

The Y chromosome is dwarfed by the X chromosome as can be seen in this image – but only in size.

This stunning discovery was based on (how else) a mistake. Perry was an African-American who lived in South Carolina, and one of his female relatives submitted a sample of his DNA to a company (which we won’t name) that conducts genealogical analysis. The data from these tests was more or less public, with hundreds of thousands of people being tested. Until Perry, geneticists concluded that all men gained their Y chromosome from a common male ancestor that lived 60.000 – 140.000 years ago… except for Perry that is.

Rewriting the family tree

Researchers tried to place his DNA on the “family tree” they created, but were unable to do so. His chromosomes were unlike anything else they encountered, because they were earlier in the tree than they were prepared for. The company was unable to go further.

Michael Hammer, a geneticist at the University of Arizona in Tucson, heard about Perry’s unusual Y chromosome and did some further testing, taking matters into his own hands.

“The Y-chromosome tree is much older than we thought,” says Chris Tyler-Smith at the Wellcome Trust Sanger Institute in Hinxton, UK, who was not involved in the study. He says further work will be needed to confirm exactly how much older.

He examined an African database of nearly 6000 Y chromosomes and found similarities between Perry’s and those in samples taken from 11 men, all living in one village in Cameroon – this is most likely where this 340.000 year old ancestors stemmed from.

Whoa! I just feel the need to take a minute and recap all this – genetical research has managed to track down the 340.000 year old ancestor of a South Carolina man to a small village in Cameroon! The emergence of information on our species in recent years is dazzling. Now, again, to clarify things a little – this is not some sort of Adam like figure whom every Human branched from; the strikingly high odds are that it is not a single Adam person, but rather a large group that acted as Adam, but I’ll beg your forgiveness, because “The Great x N Grandfather of Most Men” is sort of lacking in appeal. But the main shift here is the time frame. The first anatomically modern human fossils date back only 195,000 years, so Perry’s Y chromosome lineage split from the rest of humanity long before our species appeared – and this is where it gets really interesting.

Modern and archaic humans

What are the implications? Could this (let’s call it, for the lack of a better word) “ancient” Y chromosome be inherited from an archaic human population that has since gone extinct? Quite possible. If this is the case, the next conclusion is that some 200.000 years ago, anatomically modern humans interbred with an ancient African human. Are we talking about a new human species entirely? Almost impossible to say, but more likely the answer is ‘no’. As a matter of fact, fossil evidence seems to suggest the first hypothesis.

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In 2011, researchers examined human fossils from a Nigerian site called Iwo Eleru close to the Cameroon village I was telling you about, and found several puzzling characteristics for those fossils. First of all, the fossils showed a strange mix of ancient and modern features, which suggests that a population of more modern men was interbreeding with a more archaic population.

“The Cameroon village with an unusual genetic signature is right on the border with Nigeria, and Iwo Eleru is not too far away,” says Hammer.

I’ve done my fair work in paleontology and I know this is just wishful thinking, but finding some human fossils in the close vicinity of the village would be gold. There are already discussions of expeditions, and if successful, this kind of discovery could allow us to better understand who we are as a species, where we stem from, and who we were breeding with.

Via NewScientist

Neanderthals may have died off much earlier than thought

A new carbon dating technique developed by Australian scientists may warrant a new extinction theory for the Neanderthals, which according to the researchers made their last stand some 50,000 years ago or 15,000 years earlier than previously thought. If this is indeed a fact, then our distant extinct relatives may have never interacted with modern humans, nor interbred for that matter as other studies might suggest.

Neanderthal Scientists from the Australian National University (ANU), in collaboration with the Spanish National Distance Education University (UNED), used an improved dating method for “ultrafiltration,” a technique that removes modern carbon that can contaminate ancient collagen in bones and thus obstruct dating. Some 215 bones from 11 sites  in southern Iberia were studied.

Of this massive survey, only a handful of bones were deemed fit for analysis since the other lacked the necessary amount of collagen for accurate dating. Thus, most of the other sites could not offer clear radiocarbon dating except for Jarama VI and Zafarraya, where sufficient evidence was found that placed the earliest record to be about 50,000 years ago at two separate sites.

“Our results cast doubt on a hypothesis that has been broadly accepted since the early 1990s – that the last place for surviving Neanderthals was in the southern Iberian Peninsula,” researcher Rachel Wood, an archaeologist and radiocarbon specialist at Australian National University in Canberra, was quoted as saying in Latinos Post. “Much of the evidence that has supported this idea is based on a series of radiocarbon dates, which cluster at around 35,000 years ago. Our results call all of these results into question.”

Neanderthal – Modern human face off – a myth?

One can imagine that a theory that has been in place for roughly twenty years is not easily shaken, especially since so many ramifications have been made. Many genetic studies claim that Neanderthals and modern humans interbred, but in light of these recent findings these claims might prove to be false.

“It is improbable that the last Neanderthals of central and southern Iberia would have persisted until such a late date, approximately 30,000 years ago, as we thought before the new dates appeared” assured coauthor Jesús F. Jordá, researcher of the Department of Prehistory and Archaeology at UNED.

The researchers involved in the study themselves admit, however, that this not means that Neanderthals 100% died off 35,000 years ago. The new technique needs to be applied to other sites in Spain, as well as in other Neanderthal footholds in Europe or Crimea.

If other sites turn out to be older, then it is likely that encounters between Neanderthals and humans had to have taken place much earlier than previously believed, he added.

“Evidence from Britain, Belgium, France, Germany and Italy is increasingly pointing to a modern human presence before 40,000 years ago,” said Stringer. “The new chronology suggests that any interaction between the last Neanderthals and the earliest moderns in Europe will similarly move before, rather than after, 40,000 years.”

Previously, we reported on a genetic study which analyzed Neanderthal DNA and concluded they were on the point of dying off as a race well before humans made their appearance in Western Europe. Coupled with these latest findings, things are getting a whole lot more interesting.