Talking to ourselves and voices in our heads

We spend a lot of time listening to our own inner speech. But to what extent does the brain distinguish between inner speech and the sounds we produce when we speak out loud?

As far our brain is concerned, talking to ourselves in our heads may be fundamentally the same as speaking our thoughts out loud, new research shows. The findings may have important implications for understanding why people with mental illnesses such as schizophrenia hear voices.

UNSW Sydney scientist and study first author Associate Professor Thomas Whitford says it has long been thought that these auditory-verbal hallucinations arise from abnormalities in inner speech -- our silent internal dialogue.

"This study provides the tools for investigating this once untestable assumption," says Associate Professor Whitford, of the UNSW School of Psychology.

Previous research suggests that when we prepare to speak out loud, our brain creates a copy of the instructions that are sent to our lips, mouth and vocal cords. This copy is known as an efference-copy.

It is sent to the region of the brain that processes sound to predict what sound it is about to hear. This allows the brain to discriminate between the predictable sounds that we have produced ourselves, and the less predictable sounds that are produced by other people.

"The efference-copy dampens the brain's response to self-generated vocalisations, giving less mental resources to these sounds, because they are so predictable," says Associate Professor Whitford.

"This is why we can't tickle ourselves. When I rub the sole of my foot, my brain predicts the sensation I will feel and doesn't respond strongly to it. But if someone else rubs my sole unexpectedly, the exact same sensation will be unpredicted. The brain's response will be much larger and creates a ticklish feeling."

The study, published in the journal eLife, set out to determine whether inner speech -- an internal mental process -- elicits a similar efference-copy as the one associated with the production of spoken words.

The research team developed an objective method for measuring the purely mental action of inner speech. Specifically, their study in 42 healthy participants assessed the degree to which imagined sounds interfered with the brain activity elicited by actual sounds, using electroencephalography (EEG).

The researchers found that, just as for vocalized speech, simply imagining making a sound reduced the brain activity that occurred when people simultaneously heard that sound. People's thoughts were enough to change the way their brain perceived sounds. In effect, when people imagined sounds, those sounds seemed quieter.

"By providing a way to directly and precisely measure the effect of inner speech on the brain, this research opens the door to understanding how inner speech might be different in people with psychotic illnesses such as schizophrenia," says Associate Professor Whitford.

Read more at Science Daily

Sandy claws: Like holiday enthusiasts, majoid crabs decorate their shells

Majoid crabs, known as decorator crabs, are well-known for adorning their surface with objects such as sponges and algae.

'Tis the holiday season and it seems homes are festively trimmed at every turn. Ornaments of all shapes and sizes embellish everything from trees to windows and yards.

While tinsel originated in 17th century German decorating and modern day Christmas lights can be traced to the Victorian era, the idea of decorating is not an exclusively human trait.

Majoid crabs -- known as decorator crabs -- are well-known among marine scientists for adorning their surface with items secured from their surroundings. About 75 percent of majoid crab species are notorious for decorating with sponges, algae and other marine debris.

Scientists are uncertain what physical and environmental factors drive this decorating behavior, though it appears to be used as a means to hide from, or deter, predators.

University of Delaware marine scientist Danielle Dixson and a team of researchers that included undergraduate students studied the majoid species Camposcia retusa to identify the factors that determine patterns of, and investment in, decorating.

"The decorator crab is a perfect study example because the IndoPacific species has velcro-like substances on its shell and hooks on its appendages that enable it to secure items on its exterior," Dixson said.

The researchers ran a series of experiments with decorator crabs that were placed in individual containers and provided with craft pom-poms that had been soaked in water so they would sink to the bottom.

Half of the crabs were given a shelter for habitat to see whether having somewhere to hide affected how much or how fast the crab decorated.

Over a 24-hour period, the team photographed the crabs every hour for the first 12 hours, and at hour 24, and analyzed the images to determine where the crabs decorated, whether they rearranged things and what parts they decorated first.

Arms and legs first

In the study, all of the crabs were fully decorated within 24 hours. Most of the crabs were decorated within six hours of having access to the pom-poms. According to Dixson, this shows that decorating is an important predator adaptation because the crabs do it very quickly.

While other species of decorator crabs adorn their body first, the UD research team's study showed that Camposcia retusa decorated their appendages (arms/legs) first when a habitat was present.

This was different than other crabs that typically protect their vital organs first, but according to Dixson, still made sense because when they hide, a little bit of Camposcia retusa's arms remained outside their enclosure.

"This tells us they decorate the parts that stick out," Dixson says.

A perfect project for undergraduates

According to Dixson, this is a perfect project for undergraduates because the approach is straightforward and the students can have results in just a couple days, making it easy to add layers to the project as they go along.

It's also good way for undergrads to develop the skills to design an experiment and to refine their design based on the data collected.

For example, when no habitat was present the crabs decorated everywhere.

"The students were able to say, 'now that we know habitat matters, let's take the habitat away and see how quickly they decorate,' " Dixson said.

But just like in the holiday classic National Lampoon's Christmas Vacation, more decoration is not necessarily better. For the decorator crab, more decoration means the animal requires more energy to move around, and the slower they will be to escape predators.

Visual vs. chemical camouflage

Through ongoing research, Dixson and her students are investigating whether the crabs can actually see and choose items based on color -- meaning they are visually hiding themselves -- or whether their decorating habits are motivated by smell, known as chemical camouflage.

Sea sponges, for example, emit a scent that the crab may be using to chemically mask or camouflage itself from predators like eels, which have terrible eyesight but are known to hunt through smell.

Read more at Science Daily

The ‘Out of Africa’ Story of Human Migration Is Undergoing Major Revision

Artist's depiction of early humans migrating out of Africa

According to the "Out of Africa" model of human migration that is commonly included in textbooks the world over, some anatomically modern humans from Africa migrated in a single, rapid wave across Europe and Asia around 60,000 years ago. The model often holds that once these people were out of Africa, a brief period of interbreeding with Neanderthals occurred, helping to explain why individuals of European and Asian heritage today retain archaic human DNA.

Technological advances in the fields of genetics and archaeology over the past decade, however, are revising the story. The emerging new model, outlined in the journal Science by Petraglia and his team, shows that there were multiple dispersals of modern humans out of Africa, beginning at least 120,000 years ago.

Petraglia explained that modern human fossils dating to between 120,000–70,000 years ago have been unearthed in the Levant: the region that now includes Israel, Lebanon, western Jordan, the Sinai in Egypt, and part of Syria. Co-author Katerina Douka, also from Max Planck, said that the Levant "forms a biogeographical extension of Africa."

Aside from being a convenient place for many Africans to go, the Levant also had plenty of lakes, rivers, grasslands, and savannahs, depending on the year's climate. "This would have drawn in both animals and the hunter-gatherers that tracked them," explained Petraglia. "When the environments worsened, these regions would have become hyper-arid deserts, thus pushing people on, perhaps."

Once the individuals originating from Africa were in Europe and Asia, they encountered the Neanderthals, Denisovans, and possibly other hominid groups that were already in these areas. Anthropologists use the term "archaic" to describe such hominid groups, but this is not in the colloquial lower-level sense.

"Most researchers studying late human evolution will use the term to refer to older lineages, not directly linked to modern lineages, rather than (meaning) less evolved and adapted, or less clever," Douka said. "Neanderthals and Denisovans share a common ancestor dating to 400,000–450,000 years ago, whereas archaic and modern humans share a common ancestor dating to 520,000–650,000 years ago."

Map of sites and postulated migratory pathways associated with modern humans dispersing across Asia during the Late Pleistocene (about 126,000–5,000 years ago)

Despite such evolutionary differences, the various human groups mated with each other — possibly a lot.

Recent genetic research shows that there were multiple interbreeding events. Melanesians today, as a result, are part Denisovan, and non-Africans carry at least 1-4 percent Neanderthal DNA in their genomes. There is even DNA evidence suggesting that another, as of yet unknown, hominid contributed to the present European and Asian gene pool.

Mating between different groups was not limited to Eurasia.

"Interbreeding among various archaic Homo sapiens populations surely occurred in Africa, particularly given that Africa is considered to be the place of origin for modern humans to have arisen," co-author Christopher Bae of the University of Hawaii at Manoa told Seeker.

"This greater genetic diversity in Africa has long been considered part of the justification to consider Africa as having a longer history for modern humans than Asia," Bae said. "On a related note, though, researchers have tied higher population density in Africa as also another explanation for the higher genetic diversity on the continent."

While questions related to the when and where of humanity's origins remain hotly debated, one matter about our collective genetic makeup is clearer: All humans appear to be hominid hybrids, made up of DNA from different and distinct populations.

Adding to the complexity, Petraglia said that in the past, "there were likely many population turnovers, and probably even extinctions of human lineages that left no DNA trace in current peoples."

New research is also revising the history of Neanderthals, whose expansion across multiple regions was much greater than previously believed.

"Neanderthals were not a 'European' population like people thought until about 10 years ago,” Douka explained, “but their range was far greater, and who knows, maybe much greater than we currently think, too."

Skulls of an anatomically modern human (left) and a Neanderthal (right)

Douka mentioned recent evidence suggesting that Neanderthals once lived in China as well as in North Africa. The latter could help to explain why many Europeans who have their DNA analyzed, such as through popular kits sold online, find they possess North African DNA.

There is also no reason to assume that groups stayed put once they migrated to or from Africa. Early modern humans and other hominids could have frequently traveled back and forth, especially during favorable climatic periods.

While out-of-Africa migrations were definitely happening long before 60,000 years ago, there is evidence that such travels escalated beginning around 55,000 years ago and over the following 10,000 years.

"We see modern humans arriving in Siberia certainly by 45,000 years ago, in Europe around the same time, in southern Asia possibly a bit earlier and they are certainly present in Australia by then," Douka said.

Read more at Seeker

Newly Unearthed Remains Reveal the Complexity of Levantine Hunter-Gatherers

Remains of stone buildings at the site Shubayqa 1 in Jordan

Diners at top-tier restaurants often pay extra for items like foraged wild mushrooms, dry-farmed produce, and tisanes made out of freshly picked herbs. These items often appear on the menu of Berkeley's famous Chez Panisse, where downstairs guests can enjoy their meal in view of a comforting wood fire.

Before the dawn of agriculture in the Near East, some hunter-gatherers surprisingly enjoyed similar comforts. A recent years-long excavation of a 14,600–12,000-year-old site in Jordan unearthed the remains of elaborate stone buildings, a fire pit, artworks, stone tools, and ample food remains from what appears to have been a healthy, balanced diet.

The site, Shubayqa 1, which lies northeast of Amman, is described in the journal Scientific Reports. The research sheds light not only on the transition from foraging to farming, but also on the Natufian culture that lived there during this important time in human history.

"The Natufian culture is characterized by the appearance of solid stone buildings — indeed, some of the earliest in the world," Tobias Richter, one of the study’s authors and an associate professor at the University of Copenhagen, told Seeker.

One oval-shaped, semi-subterranean Natufian structure at the site featured a flagstone-paved floor. Maintaining the structure's look and functionality, the builders lined the fire pit with carefully placed stones.

"They also domesticated the dog as early as 14,000 years ago, which still represents some of the best evidence for the early domestication of the dog," Richter said.

He added that the Natufians were among the first societies to product art, which consisted of usually carved bone and stone figures, as well as incised stones. They also started to produce large numbers of grinding, pounding, and pulverizing tools.

Partial, carved stone Natufian artifact

Richter and his team dated more than twenty samples from different layers of Shubayqa 1, making it one of the best and more accurately dated Natufian sites in the world. The dating, directed by Elisabetta Boaretto of Israel’s Weizmann Institute of Science, involved accelerator mass spectrometry, which can reveal the amount of carbon-14 in a sample down to a single atom.

Based on this and other research, it is now believed that the Natufians lived in what is now Israel, Lebanon, and Syria, in addition to Jordan — a region commonly known as the Levant.

Previously it was thought that the Natufians first settled in the Mount Carmel and Galilee region before later fanning out. The new research suggests that the Natufians instead inhabited a variety of places at about the same time, demonstrating their versatility at adapting to different habitats.

Interestingly, some of the first modern human migrants out of Africa went to the Levant, perhaps attracted by its diverse array of animal and plant life. Certain people today therefore have Natufian ancestry.

"Some genetic traits that we know exist in Natufian populations can also be found in modern European populations and in northeast African populations," Richter explained.

Archaeologists excavating remains at the Natufian site Shubayqa 1 in Jordan

The Levant later gave rise to the world's three primary monotheistic religions — Judaism, Christianity, and Islam — that possibly have their very early roots in Natufian culture. Richter said these people buried their dead, often including grave goods with the human remains.

"Some have argued that this is evidence for the presence of ritual specialists — shamans — or some kind of group leaders," Richter said. "What seems clear is that the Natufians had developed a complex symbolic cosmology and treated their dead with respect."

Their diet was equally complex. The remains at Shubayqa 1 and at other Natufian sites show that these people hunted birds, gazelle, and other animals. A starchy staple appears to have been the tubers of the sea club-rush plant. The tubers are fibrous, and therefore require flaking or grinding to be palatable, but can reward diners with a pleasant, sweet taste.

"In addition to tubers, they relied on a wide range of other wild plants, such as cruciferous vegetables, wild cereals, and legumes," Richter said, adding that he and his team are currently writing another paper concerning the Natufian diet.

Sea club-rush in bloom in North Ayrshire, Scotland

The emerging picture of Natufian life throws a wrench into a popular theory about how agriculture began. The theory holds that as populations in the Fertile Crescent (which includes the Levant) grew, their hunter-gatherer way of life became unsustainable and they increasingly adopted agriculture.

"Personally, I am not entirely sure that this was the case," Richter said. "Our evidence certainly suggests that the Natufian culture was more variable in terms of the habitats it was able to exploit, and in terms of its plant subsistence economy."

"And," he continued, "it is problematic to treat a historical outcome as something that is inevitable."

Read more at Seeker

‘No-Cut’ CRISPR Activates Genes Without Altering DNA

The gene-editing tool CRISPR is one of the most exciting developments in modern genetics and also one of the most controversial. Described as a pair of “molecular scissors,” the CRISPR system employs an enzyme called Cas9 that binds to target sites on the genome and makes a cut in the DNA. Scientists hope to use CRISPR’s scissors to edit out genetic mutations that cause disease and replace them with healthy DNA.

While the speed and low cost of CRISPR have revolutionized in vitro gene editing in the lab, serious concerns remain about the clinical application of CRISPR. For one thing, CRISPR edits are irreversible and could trigger unintended health effects down the road.

That’s why scientists at the Salk Institute for Biological Studies went looking for a safer way to employ CRISPR in humans. Not as a gene editor, but as a gene activator.

In a paper published in the journal Cell, the Salk researchers described a new type of “no-cut” CRISPR system that was able to turn on targeted genes in living mice and reverse the effects of diseases like muscular dystrophy, diabetes, and kidney damage. 

Juan Carlos Izpisua Belmonte is a professor in the gene expression lab at the Salk Institute and lead author of the proof-of-concept study, which built upon existing research into so-called targeted gene activation systems based on modifications to CRISPR technology.

"Cutting DNA opens the door to introducing new mutations," said Belmonte in a press statement. "That is something that is going to stay with us with CRISPR or any other tool we develop that cuts DNA. It is a major bottleneck in the field of genetics — the possibility that the cell, after the DNA is cut, may introduce harmful mistakes."

Belmonte and his co-authors Hsin-Kai (Ken) Liao and Fumiyuki Hatanaka knew that other labs had been experimenting with a “dead” form of the enzyme Cas9 (dCas9) that can still bind to target sequences of DNA but doesn’t make a cut. In lab trials, other researchers had shown that dCas9 could be paired with “molecular switches” called transcriptional activation domains to locate one or more target genes and turn them on.

But the problem with these modified CRISPR systems was their size. To make CRISPR work in vivo in animals or humans, it has to be delivered by a virus, and viruses can only hold so much stuff. The modified CRISPR system simply had too many parts — the dCas9 enzyme, guide RNA, plus an activation switch — to fit in the standard viral delivery vehicles known as adeno-associated viruses (AAVs).

So the Salk team had an idea. Why not divide up the parts of the modified CRISPR system into two different packages carried by two different AAVs? One would hold the dCas9 and the other would carry the guide RNA and activation switches.

“Cas9 is a protein with many functions,” wrote Liao in an email. “It can spontaneously find guide RNA and bind to it, so it doesn’t have to be in the same package.”

Researchers from left: Hsin-Kai (Ken) Liao, Juan Carlos Izpisua Belmonte, and Fumiyuki Hatanaka

It took a lot of experimenting with different combinations of guide RNAs and switches before Belmonte and his team landed on a two-virus setup that worked together as a team inside the cell, targeting exactly right gene and flipping the switch.

To see how well the dual-virus CRISPR system worked in vivo, the Salk scientists tested how it performed against three different disease models in mice: acute kidney damage, diabetes, and muscular dystrophy. The researchers hoped that by overexpressing certain genes, they could halt or reverse the physical symptoms associated with each ailment.

In the case of acute kidney damage, the Salk team programed CRISPR to overexpress a gene called klotho that can switch off in old age and cause poor renal function. Mice injected with the CRISPR serum before injury lived longer than the control group and showed greater kidney function while alive.

Interestingly, the Salk scientists also showed that the modified CRISPR system could be used to reprogram regular liver cells to become insulin-producing cells, pointing to a potentially life-changing therapy for people with diabetes.

Read more at Seeker

Storytelling Promoted Egalitarian Values Before the Advent of Religion

An Agta storyteller

Storytelling is a human universal that likely dates back to the origin of our species. Even now, existent hunter-gatherer groups like the Agta in the Philippines include talented orators who entertain listeners with tales passed down over multiple generations.

The majority of the stories, such as the Agta's "Sun and the Moon," promote social and cooperative norms. In this particular tale, there is a dispute between the male sun and the female moon over who will illuminate the sky. After a fight, when the moon proves to be as strong as the sun, they agree to share the duty — with one working during the day and the other during the night.

Andrea Migliano of University College London (UCL) and her team recently spent time with the Agta in the Northern Sierra Madre Natural Park of Isabela Province, where they heard the tale, among others, firsthand.

"A magic moment was when we listened to the stories told by the elders, with all of the children around us laughing and really paying attention," Migliano told Seeker, still beaming at the recollection.

Aside from providing enjoyable entertainment, traditional storytelling often promotes cooperative and egalitarian values, Migliano and her team determined. In a paper published in the journal Nature Communication, she and her colleagues build a compelling case that storytelling helped to unify and strengthen human groups before comparable practices evolved in larger agricultural societies, such as the advent of organized religion with moralizing high-level gods.

Migliano was inspired to conduct the study because she is part of AgtaAid, an organization that develops educational materials for indigenous peoples in the Philippines. The Agta are descended from the first colonizers in the Philippines, who lived more than 35,000 years ago.

"Listening to the stories the Agta were telling, I realized how different they were from our own tales, and how much they seemed to be emphasizing equality," Migliano said.

When Daniel Smith, also from UCL, decided to investigate how different hunter-gatherer activities predict reproductive success, he, Migliano, and their colleagues decided to join forces to see how storytelling affected both the orators and the Agta as a whole.

The researchers asked three Agta elders to tell them stories that they normally share with their children and each other. The request resulted in four stories narrated over three nights. The researchers found that the stories about humanized natural entities, such animals or celestial bodies, promoted social and cooperative norms to coordinate group behavior.

"We then decided to test if camps (within the Agta) with good storytellers had increased levels of cooperation, without really expecting to find anything," Migliano said. "But the effect was still there. Camps with more storytellers were more cooperative. The stories seem to work."

An Agta storyteller under a shelter near a campfire

Nearly 300 members from 18 Agta camps were then asked to choose whom they would most like to live with, and storytellers were nominated nearly twice as much as less skilled speakers. In fact, talented orators were found to have, on average, 53 percent more children than others, demonstrating the reproductive benefits of being a good storyteller.

"It's definitely plausible that there is a heritable component to storytelling, but as it's also a learned behavior, any individual willing to invest the time and effort can probably learn to be a good storyteller," Smith told Seeker.

The researchers then went beyond the Agta, to see what topics other hunter-gatherer groups address in their stories. They found that 70 percent of a sample of 89 stories taken from seven other hunter-gatherer societies concerned reinforcing and regulating social behaviors.

Smith explained that storytelling is a powerful way to broadcast social norms to a group and to disseminate meta-knowledge, which is knowledge about other's knowledge, in order to organize behavior.

"This is a fundamental principle necessary for society to function," he continued. "As a simple example, it is not enough to know that you should drive on one side of the road. You also need to know that others possess the same knowledge, otherwise the system breaks down. We suggest that stories act to broadcast this meta-knowledge among all members of a community."

Agta people during nighttime storytelling around a campfire

The researchers suspect that as ancient hunter-gatherers moved from camp to camp within loosely structured groups, storytelling provided an easy and enjoyable way for people to understand different social norms and how to adapt to new rules.

"Storytelling is an efficient way to broadcast social norms and promote large-scale cooperation," Migliano said. "If I had to guess, I would put storytelling at the origins of Homo sapiens, when more fluid groups started to appear."

The authors believe that the primary difference between stories told by hunter-gatherers and those told by members of organized religions is their complexity. Both types of stories otherwise serve similar functions.

As agricultural societies became more complex and less egalitarian, however, the themes of the stories began to reflect the social changes. Nevertheless, Smith said, "the coordinating function remained."

"In the case of the high-gods and religion," Migliano said, "the argument seems to be that the fear of supernatural punishment is what makes people conform, follow the rules, and cooperate. We show that supernatural punishment is not present in these hunter-gatherer stories. Quite the opposite, they feature equality rather than hierarchy. They feature cooperation and pro-sociality, and they seem to be effective in promoting cooperation."

A young Agta boy reading a story that was published in a book created by the non-profit AgtaAid

The researchers are working to safeguard the Agta and their culture. AgtaAid has already created books in the Agta language, so that children can read the stories.

“A really emotional time for us was when AgtaAid went back (to the Philippines) with the first books and the stories reproduced in Agta,” Migliano said. “The elders could not read, but the young children read the stories back to the elders, who were really moved and happy to hear the stories they had learned as children now being told by their grandchildren."

With funding from the Leverhulme Trust, the researchers are also assisting the Agta to have the hunter-gatherers' land rights officially recognized by the Philippine government.

Read more at Seeker

Some video games are good for older adults' brains

If you're between 55 and 75 years old, you may want to try playing 3D platform games like Super Mario 64 to stave off mild cognitive impairment and perhaps even prevent Alzheimer's disease.

That's the finding of a new Canadian study by Université de Montréal psychology professors Gregory West, Sylvie Belleville and Isabelle Peretz. Published in PLOS ONE, it was done in cooperation with the Institut universitaire de gériatrie de Montréal (IUGM), Benjamin Rich Zendel of Memorial University in Newfoundland, and Véronique Bohbot of Montreal's Douglas Hospital Research Centre.

In two separate studies, in 2014 and 2017, young adults in their twenties were asked to play 3D video games of logic and puzzles on platforms like Super Mario 64. Findings showed that the gray matter in their hippocampus increased after training.

The hippocampus is the region of the brain primarily associated with spatial and episodic memory, a key factor in long-term cognitive health. The gray matter it contains acts as a marker for neurological disorders that can occur over time, including mild cognitive impairment and Alzheimer's.

West and his colleagues wanted to see if the results could be replicated among healthy seniors.

The research team recruited 33 people, ages 55 to 75, who were randomly assigned to three separate groups. Participants were instructed to play Super Mario 64 for 30 minutes a day, five days a week, take piano lessons (for the first time in their life) with the same frequency and in the same sequence, or not perform any particular task.

The experiment lasted six months and was conducted in the participants' homes, where the consoles and pianos, provided by West's team, were installed.

The researchers evaluated the effects of the experiment at the beginning and at the end of the exercise, six months later, using two different measurements: cognitive performance tests and magnetic resonance imaging (MRI) to measure variations in the volume of gray matter. This enabled them to observe brain activity and any changes in three areas:

the dorsolateral prefrontal cortex that controls planning, decision-making and inhibition;
the cerebellum that plays a major role in motor control and balance; and
the hippocampus, the centre of spatial and episodic memory.

According to the MRI test results, only the participants in the video-game cohort saw increases in gray matter volume in the hippocampus and cerebellum. Their short-term memory also improved.

The tests also revealed gray matter increases in the dorsolateral prefrontal cortex and cerebellum of the participants who took piano lessons, whereas some degree of atrophy was noted in all three areas of the brain among those in the passive control group.

What mechanism triggers increases in gray matter, especially in the hippocampus, after playing video games? "3-D video games engage the hippocampus into creating a cognitive map, or a mental representation, of the virtual environment that the brain is exploring.," said West. "Several studies suggest stimulation of the hippocampus increases both functional activity and gray matter within this region."

Conversely, when the brain is not learning new things, gray matter atrophies as people age. "The good news is that we can reverse those effects and increase volume by learning something new, and games like Super Mario 64, which activate the hippocampus, seem to hold some potential in that respect," said West. Added Belleville: "These findings can also be used to drive future research on Alzheimer's, since there is a link between the volume of the hippocampus and the risk of developing the disease."

Read more at Science Daily

Lemurs maintain gut health through 'huddling' together

Red-bellied lemur with baby.

Scientists have found a direct link between physical contact and gut bacteria in red-bellied lemurs. Likely passed through 'huddling' behaviour and touch, the new research has implications for human health.

The University of Oxford worked in collaboration with scientists from several universities, including the University of Arizona and Hunter College of the City University of New York (CUNY), on the research, published today in the Journal of Animal Ecology, to better understand causes of diversity within the animal's gut microbiome, the community of various bacteria that live inside the intestine.

These bacteria play a key role in both animal and human health, aiding digestion and tuning our individual immunity. The right mix of gut microbes set the parameters of our immune defence, blocking pathogens and informing our ability to recognise bacterial enemies, from friends.

Aura Raulo, lead author and graduate student at Oxford's Department of Zoology, said: 'In close social groups like red-bellied lemurs, social environment is key to immunity. Animals that touch each other more tend to spread microbes, both good and bad, but eventually frequent social contact leads to a synchronised microbiome. Because microbes tune immune defence, this can be seen as a form of cooperative immunity: Sharing microbial allies and enemies makes infections by opportunist pathogens less likely.

'When people with different gut microbiomes interact, they share their symbiotic bacteria through touch. This bacterial transmission can make us more or less healthy, depending on how compatible our guts are with our friends. For example, I might host a bacteria in my gut that is well-behaved, and fits my symbiotic gut community, but might turn out to be an invasive pathogen in another person who is not accustomed to it. '

Red-bellied lemurs are a very tactile, socially bonded species that live in small family groups of two to eight individuals, and spend a lot of time together. The study findings show that social groups of lemurs had markedly similar gut microbiomes and even within groups, individuals shared more similar gut community with their closest friends.

The researchers suggest that sharing a similar microbiome within a social group may have a positive health impact, essentially harmonising the immune defence and preventing members from contracting dangerous infections. Since social bonds were associated with gut microbiota, information about gut bacteria could also be used to reconstruct the social network of their hosts: who's been in contact with whom.

'The gut microbiome of red-bellied lemurs most closely resembles that of their group members. They are extremely cohesive and in contact a great deal, and rarely if ever interact with other groups, so this makes sense,' explains Andrea Baden, assistant professor of Anthropology at Hunter college, and co-senior author of the research. 'This explains a great deal of individual variation, but genetic kinship might explain some as well. We know that infants inherit a suite of microbes from their mother, during birth, for example. Since red-bellied lemurs leave their natal groups to form their own groups when they become adults, they might retain some bacteria from their natal family group. We can trace that by looking at kin relationships in the population, and similarity of the gut microbiome in kin.'

While the initial findings show clear patterns emerging, there are some challenges to this work:

Stacey Tecot, co-author and Associate Professor in the School of Anthopology at the University of Arizona, said: 'At this point our research cannot tell us whether the bacteria are good or bad, or exactly what they are -- since many are still unknown to science. To connect these results to immunity, we need to be able to distinguish pathogenic (or potentially pathogenic) microbes from beneficial ones.'

The study includes some preliminary data around the relationship between social environment, social contact, bacterial transmission and hormonal changes, such as stress. The team are currently working to build on their initial observations, with new research understanding how an individual's levels of the stress hormone cortisol are affected by their gut microbiome, as Aura explains: 'Social contact, stress physiology and gut microbiome are all intensely related. Your social contact defines how much stress you interact with, and both can influence the cocktail of microbes in your gut.

'Just like lemurs, people find social situations, such as competition sometimes stressful. However, primates also cope with stress through social means, by seeking and giving affection, grooming and touching each other, and so do people. This way, social contact also balances stress. Regardless of whether they are blood relatives, people that live in close quarters, also come to share similar gut bacteria. Synchronized physiological systems make us work more 'as one'. For example, bird pairs that have synchronized hormone levels are known to parent better as a co-operative unit. Moving forward we will be looking at how this physiological synchronisation affects cooperation in lemurs.'

Read more at Science Daily

New approach measures early human butchering practices

Archaeologist and biostatistician Erik Otárola-Castillo leads the research team that used 3-D imaging, shape analysis and Bayesian statistics to identify butchery cut marks with an 88 percent success rate in classifying butchery behaviors. The 3D imaging technology is similar to what engineers use to measure scratches on microchips and surgical blade sharpness. The findings are published in the Journal of Archaeological Science.

Researchers, led by a Purdue University anthropology professor, have found that statistical methods and 3D imaging can be used to accurately measure animal bone cut marks made by prehistoric human butchery, and to help answer pressing questions about human evolution.

Archaeologist and biostatistician Erik Otárola-Castillo leads the research team that used 3-D imaging, shape analysis and Bayesian statistics to identify butchery cut marks with an 88 percent success rate in classifying butchery behaviors. The 3-D imaging technology is similar to what engineers use to measure scratches on microchips and surgical blade sharpness.

"This approach represents a major improvement in accuracy when compared to many archaeological methods, and improving this technique will help us get the human evolution story correct," Otárola-Castillo said. "By strengthening quantitative methods to evaluate archaeological evidence, we will be able to learn more about early humans much more quickly."

The findings are published in the Journal of Archaeological Science. Otárola-Castillo is an assistant professor of the Department of Anthropology.

"In archaeology, butchery marks on animal bones are a key piece of evidence used to answer questions about food acquisition in prehistoric hunter and gatherer populations," said Otárola-Castillo, who studies hunters-gatherers' diets to answer questions about human evolution. His expertise spans North American hunters-gatherers archaeology, evolutionary biology, statistics and computational modeling.

Human-made stone tools leave cut marks on animal bone, such as sheep, deer or bison, through butchery. These cut marks can vary in size from 1 to 5 centimeters, but the depth of the cuts is often tiny, measuring at approximately 1/15 of a millimeter. Archaeologists often attempt to distinguish between cut marks made by a human's stone tool, which leaves a "V" shape, and other damage, such as trampling by a hooved animal, which can leave marks with more of a "U" shape.

Archaeologists have attempted to identify butchering marks since the 1800s. While the methods of analyzing bone marks have improved over the decades, there is still quite a lot of uncertainty and lack of consensus on how they are best measured. Current measurement techniques range from naked eye qualitative assessments to high-powered microscopy, such as scanning electron microscopy or micro-photogrammetry.

Otárola-Castillo and research teammates Emma James from The University of Queensland; Curtis W. Marean from Arizona State University; and Jessica C. Thompson from Emory University, specialize in evaluating cut marks on bone.

There are cases when marks can be ambiguous. In 2010, a couple of research teams published contradicting findings regarding bone marks from a prehistoric site, Dikika in Ethiopia. Results from their analyses varied so much they disagreed whether the marks were made by humans' tools or animals' hooves, or perhaps scratched by sand particles or other rock edges. Fresh debate now contends that some of these marks could have been made by feeding crocodiles.

"The tension over this debate has been great, because the source of the cuts matters significantly. If made by stone tools, then this is an example of stone tool-use by some of the earliest human ancestors," Otárola-Castillo said. "Recently, researchers sent bones with cut marks to various experts for analysis. The goal was to evaluate the convergence of different experts' assessments of the characteristics of the bone marks using traditional methods. Alarmingly, results showed that the qualitative assessments were inconsistent between all experts. Similar concerns also relate to modern forensics evidence, so our work is a finding that may be of interest to that field as well."

Otárola-Castillo, Marean, Thompson, and Shannon P. McPherron from the Max Planck Institute for Evolutionary Anthropology, began working on methodological improvements for bone mark analysis in 2010. Other team members are Jacob A. Harris from Arizona State University, Purdue graduate student Melissa G. Torquato and Purdue undergraduate student Hannah C. Hawkins. McPherron and Marean were members of one of the teams evaluating bones from the Dikika site in Ethiopia.

In their new study, Otárola-Castillo and the team used more than 40 cuts and slices made by volunteer butchers on sheep bones using stone tools. A "cut" represents a 90-degree incision angle, and a "slice" represents a 45-degree incision angle. The researchers then measured the cuts with a profilometer, a 3-D microscope that measures topography, roughness and layer thickness in the micro- and nanometer ranges. After measuring them, the researchers conducted a 3-D shape and size analysis of the curves and surfaces to compare the cut marks.

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More than 1,000 ancient sealings discovered

Sealings from the archive of Doliche.

Classical scholars from the Cluster of Excellence "Religion and Politics" of the University of Münster discovered a large number of sealings in south-east Turkey. "This unique group of artefacts comprising more than 1,000 pieces from the municipal archive of the ancient city of Doliche gives many insights into the local Graeco-Roman pantheon -- from Zeus to Hera to Iuppiter Dolichenus, who turned into one of the most important Roman deities from this site," classical scholar and excavation director Prof. Dr. Engelbert Winter from the Cluster of Excellence explains at the end of the excavation season. "The fact that administrative authorities sealed hundreds of documents with the images of gods shows how strongly religious beliefs shaped everyday life. The cult of Iuppiter Dolichenus did not only take place in the nearby central temple, but also left its mark on urban life," says Prof Winter. "It also becomes apparent how strongly Iuppiter Dolichenus, originally worshipped at this location, was connected with the entire Roman Empire in the 2nd and 3rd centuries AD: many of the images show the god shaking hands with various Roman emperors."

The excavation team has been exploring the temple of the soldier god Iuppiter Dolichenus for 17 years. This year, the team focussed on the urban area. "Under a mosaic dated to 400 AD within a complex of buildings, we were able to uncover an even older mosaic floor of equally high quality," Prof. Winter explains. "According to the present findings, there is much evidence of a late antique church. This could turn out to be an important contribution to understanding the history of early Christianity in this region." The excavations in the three-local aisled building complex began in 2015. Up to the present, 150 square metres of the large central nave bordered by columns have been uncovered. Engelbert Winter: "Apart from the architecture, small finds from the surrounding area also point to the existence of a church, such as the fragments of a marble table or the mentioning of a deacon attested by an inscription."

"City centre discovered"

The researchers have now also discovered the public centre of the city of Doliche, which they had first located in the eastern part of the city by geophysical prospecting. "This assumption has been confirmed," the excavation director explains. "We were able to uncover parts of a very large building: it is a public bath from the Roman Iron Age with well-preserved mosaics. Since hardly any Roman thermal baths are known so far in the region, this discovery is of great academic importance." The research team from Münster also gained new insights to the extension of the urban area and the chronology of the city: an intensive survey carried out this year on the settlement hill of the ancient city, Keber Tepe, led to quite surprising results. "A large number of finds from the Stone Age indicate that Keber Tepe was obviously an extremely important place very early on. Doliche reached its greatest extent later, in the Roman and early Byzantine periods."

Excavation director Winter says about the large number of discovered sealings: "Many sealings can be attributed to the administrative or official seals of the city due to their size, frequent occurrence, and in some cases also due to inscriptions. In addition to the images of the 'city goddess' Tyche, the depictions of Augustus and Dea Roma deserve special attention, since they point to the important role of the Roman emperor and the personified goddess of the Roman state for the town of Doliche, which lies on the eastern border of the Roman Empire. However, the central motif is the most important god of the city, Iuppiter Dolichenus. In the 2nd and 3rd centuries AD, his cult spread into large parts of the Mediterranean world, extending as far as Britain," explains Prof. Winter. Therefore, it is not surprising that hundreds of documents were sealed with images showing a handshake between this deity and an emperor. "It was a sign of the god's affinity to the Roman state."

The images also provide insights into the cult itself. In addition to sealings showing busts of Iuppiter and his wife Iuno, there are depictions of the divine twins Castor and Pollux, the sons of Zeus. "The sons of Zeus, also known as Dioscuri or Castores Dolicheni, are often portrayed as companions of Iuppiter and therefore play an important role in the cult," Prof. Winter explains.

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How the oldest compound eyes were constructed

Trilobite fossil

Researchers from Cologne, Tallinn, and Edinburgh have found out that the compound eyes of today's arthropods are still constructed in much the same way as they were in their ancestors 500 million years ago. The research team looked at fossil trilobites. However, these arthropods lacked the lenses of contemporary compound eyes. The zoologist Dr Brigitte Schoenemann and her colleagues have now published the results of their research in the Proceedings of the National Academy of Sciences.

Dr Brigitte Schoenemann (University of Cologne) and her colleagues Helje Pärnaste (Tallinn, Estonia), and Euan Clarkson (Edinburgh, Scotland) have succeeded in unraveling the structure and functioning of the oldest known compound eye. The researchers used an exceptionally well-preserved fossil trilobite (Schmidtiellus reetae), which is over half a billion years old, showing the cellular structure of a compound eye. It not only shows how this eye was constructed, but also its functioning, its performance, and how it differs from contemporary compound eyes. The results show that modern compound eyes work in ways strikingly similar to those of half a billion years ago. They are very conservative in their structure -- and quite successfully so. "The principle of the modern compound eye most likely goes back to before the times of our first fossil records. Half a billion years ago, it was in the early stage of its development, and with our work we have succeeded in uncovering the first visible steps of this extremely successful visual principle," says Schoenemann.

The eye belongs to a trilobite found in Estonia, an extinct arthropod that lived in the oceans of the Palaeozoic. The findings from this geological layer have brought to light the very first fossils of complex animals. The right eye of the trilobite is slightly abraded, allowing for a view into its interior. It is a typical compound eye consisting of approximately 100 subunits placed relatively far apart compared to modern forms. The authors were able to show that each of these subunits (ommatidia) consists of about eight sensory cells -- just like modern compound eyes -- grouped around a central rhabdom, a light-guiding receptive structure. The latter contains the visual pigments and conveys the brightness of the surrounding environment to the animal's central nervous system.

"However, in contrast to the modern compound eyes of bees, dragonflies, and many crabs, this very old compound eye does not have a lens," Schoenemann explains. "This is likely due to the fact that these rather soft-shelled arthropods lacked the necessary layer in their shell responsible for lens formation." The physical features of the central rhabdom ensures that each element of the compound eye has a limited field of vision and that the animal's overall visual impression already has the mosaic-like character of a modern compound eye. The precision of such an eye can be determined by the number of its elements -- just like the number of pixels determines the precision of a computer graphic. "With approximately 100 'pixels,' the performance of this eye dating back more than half a billion years is certainly not outstanding. But it was sufficient to provide the trilobite with information on movement in its field of vision, for example approaching predators. It could roughly discern the distribution of light in its surroundings or avoid obstacles in its path," says Schoenemann.

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Scientists observe supermassive black hole in infant universe

Artist's conceptions of the most-distant supermassive black hole ever discovered, which is part of a quasar from just 690 million years after the Big Bang. It is surrounded by neutral hydrogen, indicating that it is from the period called the epoch of reionization, when the universe's first light sources turned on.

A team of astronomers, including two from MIT, has detected the most distant supermassive black hole ever observed. The black hole sits in the center of an ultrabright quasar, the light of which was emitted just 690 million years after the Big Bang. That light has taken about 13 billion years to reach us -- a span of time that is nearly equal to the age of the universe.

The black hole is measured to be about 800 million times as massive as our sun -- a Goliath by modern-day standards and a relative anomaly in the early universe.

"This is the only object we have observed from this era," says Robert Simcoe, the Francis L. Friedman Professor of Physics in MIT's Kavli Institute for Astrophysics and Space Research. "It has an extremely high mass, and yet the universe is so young that this thing shouldn't exist. The universe was just not old enough to make a black hole that big. It's very puzzling."

Adding to the black hole's intrigue is the environment in which it formed: The scientists have deduced that the black hole took shape just as the universe was undergoing a fundamental shift, from an opaque environment dominated by neutral hydrogen to one in which the first stars started to blink on. As more stars and galaxies formed, they eventually generated enough radiation to flip hydrogen from neutral, a state in which hydrogen's electrons are bound to their nucleus, to ionized, in which the electrons are set free to recombine at random. This shift from neutral to ionized hydrogen represented a fundamental change in the universe that has persisted to this day.

The team believes that the newly discovered black hole existed in an environment that was about half neutral, half ionized.

"What we have found is that the universe was about 50/50 -- it's a moment when the first galaxies emerged from their cocoons of neutral gas and started to shine their way out," Simcoe says. "This is the most accurate measurement of that time, and a real indication of when the first stars turned on."

Simcoe and postdoc Monica L. Turner are the MIT co-authors of a paper detailing the results, published today in the journal Nature. The other lead authors are from the Carnegie Institution for Science, in Pasadena, California.

A shift, at high speed

The black hole was detected by Eduardo Bañados, an astronomer at Carnegie, who found the object while combing through multiple all-sky surveys, or maps of the distant universe. Bañados was looking in particular for quasars -- some of the brightest objects in the universe, that consist of a supermassive black hole surrounded by swirling, accreting disks of matter.

After identifying several objects of interest, Bañados focused in on them using an instrument known as FIRE (the Folded-port InfraRed Echellette), which was built by Simcoe and operates at the 6.5-meter-diameter Magellan telescopes in Chile. FIRE is a spectrometer that classifies objects based on their infrared spectra. The light from very distant, early cosmic objects shifts toward redder wavelengths on its journey across the universe, as the universe expands. Astronomers refer to this Doppler-like phenomenon as "redshift"; the more distant an object, the farther its light has shifted toward the red, or infrared end of the spectrum. The higher an object's redshift, the further away it is, both in space and time.

Using FIRE, the team identified one of Bañados' objects as a quasar with a redshift of 7.5, meaning the object was emitting light around 690 million years after the Big Bang. Based on the quasar's redshift, the researchers calculated the mass of the black hole at its center and determined that it is around 800 million times the mass of the sun.

"Something is causing gas within the quasar to move around at very high speed, and the only phenomenon we know that achieves such speeds is orbit around a supermassive black hole," Simcoe says.

When the first stars turned on

The newly identified quasar appears to inhabit a pivotal moment in the universe's history. Immediately following the Big Bang, the universe resembled a cosmic soup of hot, extremely energetic particles. As the universe rapidly expanded, these particles cooled and coalesced into neutral hydrogen gas during an era that is sometimes referred to as the dark ages -- a period bereft of any sources of light. Eventually, gravity condensed matter into the first stars and galaxies, which in turn produced light in the form of photons. As more stars turned on throughout the universe, their photons reacted with neutral hydrogen, ionizing the gas and setting off what's known as the epoch of re-ionization.

Simcoe, Bañados, and their colleagues believe the newly discovered quasar existed during this fundamental transition, just at the time when the universe was undergoing a drastic shift in its most abundant element.

The researchers used FIRE to determine that a large fraction of the hydrogen surrounding the quasar is neutral. They extrapolated from that to estimate that the universe as a whole was likely about half neutral and half ionized at the time they observed the quasar. From this, they inferred that stars must have begun turning on during this time, 690 million years after the Big Bang.

"This adds to our understanding of our universe at large because we've identified that moment of time when the universe is in the middle of this very rapid transition from neutral to ionized," Simcoe says. "We now have the most accurate measurements to date of when the first stars were turning on."

There is one large mystery that remains to be solved: How did a black hole of such massive proportions form so early in the universe's history? It's thought that black holes grow by accreting, or absorbing mass from the surrounding environment. Extremely large black holes, such as the one identified by Simcoe and his colleagues, should form over periods much longer than 690 million years.

"If you start with a seed like a big star, and let it grow at the maximum possible rate, and start at the moment of the Big Bang, you could never make something with 800 million solar masses -- it's unrealistic," Simcoe says. "So there must be another way that it formed. And how exactly that happens, nobody knows."

Read more at Science Daily

Synchrotron sheds light on the amphibious lifestyle of a new raptorial dinosaur

Reconstruction of Halszkaraptor escuilliei. This small dinosaur was a close relative of Velociraptor, but in both body shape and inferred lifestyle it much closely recalls some waterbirds like modern swans.

An exceptionally well-preserved dinosaur skeleton from Mongolia unites an unexpected combination of features that defines a new group of semi-aquatic predators related to Velociraptor. Detailed 3D synchrotron analysis allowed an international team of researchers to present the bizarre 75 million-year-old predator, named Halszkaraptor escuilliei, in Nature. The study not only describes a new genus and species of bird-like dinosaur that lived during the Campanian stage of the Cretaceous in Mongolia but also sheds light on an unexpected amphibious lifestyle for raptorial dinosaurs.

Theropods encompass all carnivorous dinosaurs, including the largest land-living predators in the history of life on Earth, such as Tyrannosaurus, and iconic agile hunters like Velociraptor. During 160 million years of the Mesozoic Era, theropods became the dominant predators on all continents, yet never conquered aquatic environments. Although some theropods reportedly incorporated fish in their diet, proposed indications for aquatic locomotion associated with exclusively aquatic lifestyles remain controversial.

A swan-necked and flipper-forelimbed new dinosaur species that combines an unexpected mix of features now demonstrates that some bird-like dinosaurs did adopt a semi-aquatic lifestyle. The fossil, nicknamed "Halszka" for Halszkaraptor escuilliei, was found at Ukhaa Tolgod. This locality in southern Mongolia has been known by palaeontologists for decades and is often targeted by poachers. "Illicit fossil trade presents a great challenge to modern palaeontology and accounts for a dramatic loss of Mongolian scientific heritage," says Pascal Godefroit of the Royal Belgian Institute of Natural Sciences in Brussels. "Illegally exported from Mongolia, Halszka resided in private collections around the world before it was acquired in 2015 and offered to palaeontologists for study and to prepare its return to Mongolia."

Although several important groups of predatory dinosaurs have been discovered in Mongolia, Halszka does not belong to any of them, having a number of strange features that are mostly absent among dinosaurs, but are shared by reptilian and avian groups with aquatic or semiaquatic ecologies. "The first time I examined the specimen, I even questioned whether it was a genuine fossil" says Andrea Cau of the Geological Museum Capellini in Bologna. Although Halszka is unique in many ways, certain parts of the skeleton, including the sickle-shaped "killer claws" on its feet, are shared with well-known dinosaurs such as Velociraptor. "This unexpected mix of traits makes it difficult to place Halszka within traditional classifications," Cau remarks.

In order to ascertain the integrity of the fossil, the specimen was visualised and reconstructed in three dimensions using synchrotron multi-resolution X-ray microtomography. "This technique is currently the most powerful and sensitive method to image internal details without damaging invaluable fossils. The ESRF has become the worldwide leader for high quality X-ray imaging of such precious specimens," notes Paul Tafforeau of the ESRF. "We had to mobilise an ESRF team of palaeontologists to study the complete anatomy of Halzka. So far, it's the specimen for which the greatest number of experiments were made on a single fossil," adds Tafforeau.

"Our first goal was to demonstrate that this bizarre and unexpected fossil is indeed a genuine animal: multi-resolution scanning confirmed that the skeleton is not a composite assembled from parts of different dinosaurs," explains Dennis Voeten of the ESRF. "We implemented new methods for the acquisition and optimisation of tomographic scan data, which not only confirmed the integrity of the specimen, but also revealed additional palaeontological information," Vincent Fernandez of the ESRF clarifies.

The synchrotron was even able to reveal, in astonishing detail, those parts of the skeleton that have remained deep within the rock ever since the dinosaur got buried. "Our analysis demonstrated that numerous teeth, which are not visible externally, are still preserved inside the mouth," says Vincent Beyrand of the ESRF. "We also identified a neurovascular mesh inside its snout that resembles those of modern crocodiles to a remarkable degree. These aspects suggest that Halszka was an aquatic predator."

The ESRF data revealed that the fossil represents a new genus and species of amphibious dinosaur that walked on two legs on land, with postural adaptations similar to short-tailed birds (like ducks), but used its flipper-like forelimbs to manoeuvre in water (like penguins and other aquatic birds), relying on its long neck for foraging and ambush hunting.

This new species was named Halszkaraptor escuilliei. Its generic name honours the late palaeontologist Halszka Osmólska. "This important genus is named in recognition of Halszka's contribution to the study of Mongolian dinosaurs from the Gobi," comments Rinchen Barsbold of the Mongolian Academy of Sciences. "The specific name refers to François Escuillié and thereby acknowledges his role in the first recognition and in the return of this specimen to Mongolia," adds Khishigjav Tsogtbaatar of the Institute of Paleontology and Geology in Ulaanbaatar.

Halszkaraptor is not the only strange dinosaur recovered from the Gobi. Several previously described enigmatic Mongolian theropods were closely related to the new species, the study found. United in a new group, named Halszkaraptorinae, "is an unexpected subfamily of dromaeosaurs -- the group colloquially known as raptors. This bizarre subfamily appears to have evolved a lifestyle different from all other predatory dinosaurs," says Philip Currie of the University of Alberta.

Read more at Science Daily

DNA Analysis Reveals the True Identity of Himalayan Yetis

Recreation of Yeti (left), brown bear cubs playing in water (right)

Yeti, aka the Abominable Snowman, has vexed scientists for over 200 years.

In 1925, for example, Royal Geographical Society photographer N.A. Tombazi observed a creature — deemed by others as Yeti — about 15,000 feet near the largest glacier in the Eastern Himalayas. Tombazi at the time wrote: "Unquestionably, the figure in outline was exactly like a human being, walking upright and stopping occasionally to pull at some dwarf rhododendron bushes. It showed up dark against the snow, and as far as I could make out, wore no clothes."

Supposed remains of Yeti were even collected over the centuries, including desiccated fecal material, hair, a scrap of skin, a fragment of bone from a decayed body found in a Tibetan Plateau cave, and other items.

The British production company Icon Films, creator of the documentary Yeti or Not, gathered such remains and presented them to Charlotte Lindqvist and her team for DNA analysis. Lindqvist is an associate professor of biological sciences at the University of Buffalo College of Arts and Sciences.

The results of the scientific investigation have just been released. Lindqvist and her team report that six of the supposed Yeti remains were from Tibetan brown bears, one was from a Himalayan brown bear, another was from an Asian black bear, and one turned out to be from a dog.

Himalayan brown bear from Deosai National Park, Pakistan

The findings, published in the journal Proceedings of the Royal Society B, represent the most rigorous analysis to date of samples suspected to derive from anomalous or mythical human-like creatures, according to the researchers.

"Our evidence strongly points to a biological basis for the Yeti myth, and the more evidence we have that confirms that, the more unlikely it becomes that there is some other explanation for the myth," Lindqvist told Seeker.

"But," she added, "that will most likely never change the belief in the myth."

The appearance and behavior of the bears identified in the study provide clues as to how the myth might have begun and persisted for so long.

Co-author Muhammad Ali Nawaz from Quaid-i-Azam University and the Snow Leopard Trust Pakistan program explained to Seeker that Himalayan brown bears are smaller than other bear species and can look human-sized when standing, which they do, he said, "while smelling around, perceiving threats, climbing trees" and more. He added that their fur color is quite variable, with some sporting light brown shades.

A femur from the decayed body of a purported Yeti that was found in a cave in Tibet. Biologist Charlotte Lindqvist tested DNA from the bone for Yeti or Not, which aired on Animal Planet in 2016. The bone was found to belong to a Tibetan brown bear.

"They hibernate during winter in areas close to villages," he continued, "and sometimes visit houses to steal food. Attacks on humans are extremely rare, though, based on our monitoring of Himalayan brown bears in Deosai National Park, Pakistan for about 20 years."

Co-author Richard Bischof from the Norwegian University of Life Sciences added, "One attribute of Himalayan brown bears that may further facilitate the myth is the fact that they can range up to very high elevations. Encounters there must leave an impression, especially if the bear rears up to get a better look at the human intruder, before disappearing."

Okapi at Disney's Animal Kingdom

The Yeti myth isn’t the only one to be debunked by scientific analysis. The longstanding Western legend of an "African unicorn" was explained in the early 20th century as being an okapi: a giraffe relative that resembles a mix between not only a giraffe, but also a zebra and a horse.

Creatures from Australia's Aboriginal Dreamtime mythology are now believed to have been drawn from ancient encounters with real megafauna, known today from that country's fossil record.

"Ancient myths could have a basis in long extinct animals, or perhaps even other human species that modern humans encountered when they colonized the area," Lindqvist said. Some myths could therefore have been in existence for tens of thousands of years, passed down orally before the emergence of written accounts.

Not all mysteries associated with Yeti have been solved, however. A few years ago, another research team led by Bryan Sykes of the University of Oxford analyzed 30 hair samples attributed to Yeti, Bigfoot, and other anomalous primates.

Sykes and his colleagues told Seeker that two of the studied hairs could not be matched to a known bear species. They said the animal possibly was a hybrid, a bear with an unknown "color variant," or "a previously unrecognized bear."

"Although none of the Bigfoot hairs were from an anomalous primate, this does not prove that Bigfoot does not exist,” Sykes said. “Absence of proof is not proof of absence."

There is further puzzlement about the bears identified in the latest paper. The researchers' analysis of mitochondrial DNA — genetic information passed down through the female line — showed that while Tibetan brown bears share a close common ancestry with North American and Eurasian bears, Himalayan brown bears belong to a distinct evolutionary lineage.

"Our data suggests that Himalayan brown bears may be representative of the most ancient lineage of brown bears, having shared a common ancestor with all other living brown bears more than 600,000 years ago," co-author Stephanie Gill of the University of Buffalo explained to Seeker.

"They appear to have migrated into the area and been isolated ever since," Gill added. "Thus, Himalayan brown bears living today may provide a sort of window into what the ancestor of all brown bears was like."

Lindqvist admitted that she and her team are missing the male side of the story. “It is possible that these bear populations are more connected than we realize,” she said, “but that it is only the male bears that move across the mountains."

Another possibility is that around 650,000 years ago, during a period of glaciation, Himalayan brown bears became separated from other bears. That population could then have undergone a prolonged period of isolation and evolved on an independent path.

In the future, the researchers hope to sequence the nuclear genomes of Himalayan and Tibetan brown bears, permitting a more complete look at these species' history.

Read more at Seeker

Astronomers Find Two Massive Galaxies Amid an Ocean of Dark Matter

Artist impression of a pair of galaxies from the very early universe

Astronomers have found a pair of surprisingly gigantic galaxies from the early universe, and one is the most massive galaxy ever seen from when the universe was young. Observations show the pair of big galaxies existed less than 800 million years after the Big Bang, and their size doesn’t conform to current cosmological models, which say early galaxies were much smaller than today’s galaxies.

Additionally, the discovery provides new details on the role that dark matter played in assembling large structures in the universe. Astronomers say the amount of dark matter that “clumped” in one area in order to create galaxies this large would have been quite rare.

“The fact that we see two big galaxies together strengthens the case that we’re looking at a particularly dense region in the universe, where gravity has assembled a large mass of dark matter in which to form these galaxies,” Dan Marrone from the University of Arizona in Tucson told Seeker.

“However,” he added, “the fact that one very massive dark matter halo has been found at this time is not too surprising, as there should be a handful in the universe according to current cosmology. If we saw a lot of these galaxies as we continued with our survey, it would be surprising and it might suggest that we don’t understand something about how dark matter structures forms.”

Marrone is the lead author on a new paper published in the journal Nature describing the findings.

The two galaxies are quite close, separated by a distance less than that between Earth and the center of our galaxy. Astronomers expect that the pair will likely merge to form the largest galaxy that has ever been observed during the first billion or so years of cosmic history.

The pair of galaxies was originally spotted by the South Pole Telescope in Antarctica, and observations indicated that the duo might be one incredibly large light source. Complicating matters was that another galaxy was in the way, creating a gravitational lens, bending the path of the incoming light and magnifying the source. Scientists didn't know if the light source — known as SPT0311-58 — was heavily magnified and tiny or lightly magnified and massive. Normally, gravitational lensing can help increase spatial resolution of the background galaxy, but Marrone said in this case it was more of a nuisance because the lensing was quite weak.

That prompted observations with Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, which has better resolution. The team determined the light source was from two separate but close galaxies, and the light from these galaxies took around 13 billion years to reach Earth, so they appear as they did when the universe was young.

Deconstructing the lensing process provided intriguing details about the galaxies, such as a surprisingly large amount of gas and dust for galaxies during that period in the universe. Also, the galaxies were forming stars at an extremely high rate, about 2,900 solar masses per year. Astronomers think this means that the two galaxies are merging.

“Galaxies often interact and merge to form larger galaxies, and these interactions can cause the galaxies to form stars at a faster rate than they would otherwise,” co-author Chris Hayward said in an email to Seeker. Hayward is an associate research scientist at the Center for Computational Astrophysics at the Flatiron Institute in New York City.

The gravitational tidal forces exerted by the galaxies on one another can cause the gas in the galaxies to become denser. This makes the interacting galaxies especially bright and therefore easier to detect.

“We often find that the very brightest galaxies appear to be collisions of two galaxies near the end of the merger process, when the star formation enhancement is strongest,” Hayward explained. “The high star-formation rate inferred for this pair of galaxies may be a product of the interaction between the two galaxies.”

Marrone added that early in the universe, galaxy collisions happened frequently, especially in regions with the strongest gravitational pull from the dark matter structure.

The prevailing theory was that smaller galaxies in the early universe were the building blocks to create larger galaxies, and that larger galaxies came into existence only after the first few billion years.

Read more at Seeker

Archaeologists revise chronology of the last hunter-gatherers in the Near East

Archaeologists working at the Shubayqa 1 site.

New research by a team of scientists and archaeologists based at the Weizmann Institute of Science and the University of Copenhagen suggests that the 15,000-year-old 'Natufian Culture' could live comfortably in the steppe zone of present-day eastern Jordan -- this was previously thought to be either uninhabitable or only sparsely populated.

The hunter-gatherers of the Natufian Culture, which existed in modern-day Israel, Jordan, Lebanon and Syria between c. 14,500 -- 11,500 years ago, were some of the first people to build permanent houses and tend to edible plants. These innovations were probably crucial for the subsequent emergence of agriculture during the Neolithic era. Previous research had suggested that the centre of this culture was the Mount Carmel and Galilee region, and that it spread from here to other parts of the region. The new study by the Copenhagen-Weizmann team, published in Scientific Reports, challenges this 'core region' theory.

The new paper is based on evidence from a Natufian site located in Jordan, c. 150 km northeast of Amman. The site, called Shubayqa 1, was excavated by a University of Copenhagen team led by Dr. Tobias Richter from 2012-2015.

The excavations uncovered a well-preserved Natufian site, which produced a large assemblage of charred plant remains. These kinds of botanical remains are rare at many other Natufian sites in the region, and enabled the Weizmann-Copenhagen team to obtain the largest number of dates for any Natufian site yet in Israel or Jordan.

"We dated more than twenty samples from different layers of the site, making it one of the best and most accurately dated Natufian sites anywhere. The dates show, among other things, that the site was first settled not long after the earliest dates obtained for northern Israel, ca. 14,600 years ago. This suggests that the Natufian either expanded very rapidly, which we think is unlikely, or that it emerged more or less simultaneously in different parts of the region," Dr. Richter reports, adding:

"The early date of Shubayqa 1 also shows that Natufian hunter-gatherers were more versatile than previously thought. Past research had linked the emergence of the Natufian to the rich habitat of the Mediterranean woodland zone. But the early dates from Shubayqa show that these late Pleistocene hunter-gatherers were also able to live quite comfortably in more open parkland steppe zones further east. Some of their subsistence appears to have relied heavily on the exploitation of club rush tubers, as well as other wild plants. They also hunted birds, gazelle and other animals," says Tobias Richter.

Precise dating methodology

The dating was undertaken by Professor Elisabetta Boaretto at the Weizmann Institute of Science using Accelerator Mass Spectrometry, or AMS, dating. Boaretto is head of the D-REAMS lab in the Weizmann Institute -- one of the few labs in the world that works with the technology and methods to analyze even the smallest organic remains from a site and precisely date them.

Using a specially designed mass spectrometer, Boaretto is able to reveal the amount of carbon-14 in a sample down to the single atom. Based on the half-life of the radioactive carbon-14 atoms, the dating done in her lab is accurate to around 50 years, plus or minus. For the analysis of the specimen from Shubayqa, the team was able to select only short-lived plant species or short-lived plant parts, such as seeds or twigs, to obtain the dates. This ensured the highest possible accuracy for the dates.

Boaretto says that the "core area" theory may have come about, in part, because the Mt. Carmel sites have been the best preserved and studied, until now. In addition to calling into question the idea of the Natufian beginning in one settlement and spreading outwards, the study suggests that the hunter-gatherers who lived 12,000 to 15,000 years ago were ingenious and resourceful. They learned to make use of numerous plants and animals where ever they were, and to tend them in a way that led to early settlement.

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