The genetic origins of the world's first farmers clarified

Ancient DNA extraction in Mainz’s lab. Work done in sterile conditions to avoid contamination from modern DNA.
Credit: Joachim Burger / JGU

The genetic origins of the first agriculturalists in the Neolithic period long seemed to lie in the Near East. A new study published in the journal Cell shows that the first farmers actually represented a mixture of Ice Age hunter-gatherer groups, spread from the Near East all the way to south-eastern Europe. Researchers from the University of Bern and the SIB Swiss Institute of Bioinformatics as well as from the Johannes Gutenberg University Mainz and the University of Fribourg were involved in the study. The method they developed could help reveal other human evolution patterns with unmatched resolution. 

The first signs of agriculture and a sedentary lifestyle are found in the so-called 'Fertile Crescent', a region in the Near East where people began to settle down and domesticate animals and plants about 11,000 years ago. The question of the origin of agriculture and sedentism has occupied researchers for over 100 years: did farming spread from the Near East through cultural diffusion or through migration? Genetic analyses of prehistoric skeletons so far supported the idea that Europe's first farmers were descended from hunter-gatherer populations in Anatolia. While that may well be the case, this new study shows that the Neolithic genetic origins cannot clearly be attributed to a single region. Unexpected and complex population dynamics occurred at the end of the Ice Age, and led to the ancestral genetic makeup of the populations who invented agriculture and a sedentary lifestyle i.e. the first Neolithic farmers. 

The first farmers emerged from a mixing process starting 14,000 years ago 

Previous analyses had suggested that the first Neolithic people were genetically different from other human groups from that time. Little was known about their origins. Nina Marchi, one of the study's first authors from the Institute of Ecology and Evolution at the University of Bern and SIB says: "We now find that the first farmers of Anatolia and Europe emerged from a population admixed between hunter-gatherers from Europe and the Near East." According to the authors, the mixing process started around 14,000 years ago, which was followed by a period of extreme genetic differentiation lasting several thousand years. 

A novel approach to model population history from prehistoric skeletons 

The Klein7 individual from the Kleinhadersdorf site in the Lower Austrian Weinviertel, whose genome was analyzed in the paper.
Credit: BDA / Christine Neugebauer-Maresch

This research was made possible by combining two techniques: the production of high-quality ancient genomes from prehistoric skeletons, coupled with demographic modeling on the resulting data. The research team coined the term "demo genomic modeling" for this purpose. "It is necessary to have genome data of the best possible quality so that the latest statistical genomic methods can reconstruct the subtle demographic processes of the last 30 thousand years at high resolution", says Laurent Excoffier, one of the senior authors of the study. Laurent Excoffier is a professor at the Institute of Ecology and Evolution at the University of Bern and group leader at SIB. He initiated the project together with Joachim Burger of the Johannes Gutenberg University in Mainz and Daniel Wegmann of the University of Fribourg. Nina Marchi adds: "Simply comparing the similarity of different ancient genomes is not enough to understand how they evolved. We had to reconstruct the actual histories of the populations studied as accurately as possible. This is only possible with complex population genetic statistics." 

Interdisciplinary key to solve such ancient puzzles 

Joachim Burger of the University of Mainz and second senior author emphasizes the necessity of interdisciplinarity: "It took close to ten years to gather and analyze the skeletons suitable for such a study. This was only possible by collaborating with numerous archaeologists and anthropologists, who helped us to anchor our models historically". The historical contextualization was coordinated by Maxime Brami, who works with Burger at Johannes Gutenberg University. The young prehistorian was surprised by some of the study's findings: "Europe's first farmers seem to be descended from hunter-gatherer populations that lived all the way from the Near East to the Balkans. This was not foreseeable archaeologically". 

Towards a general model of human population evolution 

Genetic data from fossils (skeletons) are badly damaged and must be processed accordingly using bioinformatics, as Daniel Wegmann from the University of Fribourg and group leader at SIB explains: "The high-resolution reconstruction of the prehistory of the Europeans was only possible thanks to methods that we specifically developed to analyze
ancient fossil genomes." Joachim Burger adds: "With these approaches, we have not only elucidated the origins of the world's first Neolithic populations, but we have established a general model of the evolution of human populations in Southwest Asia and Europe." 

"Of course, spatial and temporal gaps remain, and this does not imply the end of studies on the evolution of humans in this area", concludes Laurent Excoffier. Thus, the team's research plan is already set; they want to supplement their demographic model with genomes from the later phases of the Neolithic and Bronze Ages to provide an increasingly detailed picture of human evolution. 

Source/Credit: University of Bern

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International project aims to understand and protect endangered sea turtles

A hawksbill sea turtle (Eretmochelys imbricata)
Credit: Kate Charles, Ocean Spirits Inc

A partnership of organizations and universities in the UK and Grenada has launched a new project looking into the challenges and threats facing two endangered marine species.

Marine conservationists in the two countries will be working to understand more about hawksbill sea turtles (Eretmochelys imbricata) and green sea turtles (Chelonia mydas).

This will include using a variety of field techniques to fully appreciate their behaviors and habitats, and ultimately, the partners hope to develop a series of measures that can be used to support the sustainable conservation of the species now and in the future.

The research is being funded by the Oscar Montgomery Environmental Foundation (OMEF), a charity launched in 2020 as a legacy to a young man who was passionate about the marine environment.

He died, aged just 17, and the charity set up in his memory aims to support, advocate and raise awareness of environmental issues, largely marine, and support projects and research which work to conserve and enhance the global environment.

Powering the moon

An artistic rendering of a resilient microgrid for a lunar base camp
might look like. Sandia National Laboratories engineers are working with
NASA to design the system controller for the microgrid.
Illustration by Eric Lundin

Sandia National Laboratories is well-known for designing reliable and resilient microgrids for military bases and vital city services. Now, Sandia researchers are working with NASA to design one for the moon.

This is not the first time Sandia has partnered with NASA to power equipment on the moon. In fact, Sandia provided the technical direction for the radioisotope thermoelectric generators that powered the lunar experiments placed by many of the Apollo missions.

NASA’s plan for its concept Artemis lunar base is that it will serve as a technology proving ground for the eventual human exploration of Mars, said Jack Flicker, a Sandia electrical engineer. The base camp concept consists of a habitation unit — complete with room for up to four astronauts — as well as the potential for separate mining and fuel processing, called in-situ resource utilization, facilities. Early Artemis missions will include short stays at the base camp with the goal to build up to stays of two months at a time.

The mining and processing facilities could produce rocket fuel, water, oxygen and other materials needed for extended exploration of the lunar surface while decreasing supply needs from Earth. This facility will be located far away from the base camp — so other science and technology activities conducted there won’t be disrupted — but the electrical grid for the two units will be connected during emergencies for resiliency and robustness, Flicker added.

Precision oncology helps prostate cancer patients

Brain metastasis of prostate cancer with selected intratumoral areas (pink and white circles) for undergoing molecular analyses.
Credit: Antonio Rodriguez, Dept. of Pathology and DBMR

Researchers at the University of Bern and University Hospital Bern have achieved a breakthrough in a particularly aggressive form of prostate cancer. In tissue samples from advanced brain metastases, they were able to establish the genetic profile of the cancer cells. These findings show for the first time that affected patients could benefit from target treatment, from which they have so far not been eligible.

Around 6,600 men are diagnosed with prostate cancer in Switzerland every year. It is the second most common cause of cancer-related death in men after lung cancer. Dangerous are advanced stages in which cancer cells have spread to other organs and form so-called metastases. However, unlike other cancers such as breast or lung cancer, the extremely dangerous metastases in the brain are very rare in prostate cancer. Only 1.5 percent of advanced cases have been diagnosed as brain metastatic prostate cancer (PCBM), according to a 2020 review study. As a result, PCBM cases have been poorly studied.

What Makes Some More Afraid of Change Than Others?

Being fearless can help wildlife, specifically birds, find new food sources, explore new nesting areas and help them adapt to changes in their environment; but being afraid can also help protect them from dangerous novel things in their environment such as cars. Scientists have discovered significant differences in how the brain works in two distinct personality types: those who act fearless and those who seem afraid of new things.

Humans are undoubtedly altering the natural environment. But how wild animals respond to these changes is complex and unclear. In a new study published today, scientists have discovered significant differences in how the brain works in two distinct personality types: those who act fearless and those who seem afraid of new things. Being fearless can help wildlife, specifically birds, find new food sources, explore new nesting areas and help them adapt to changes in their environment; but being afraid can also help protect them from dangerous novel things in their environment such as cars.

“Our study provides interesting and important evidence that some of the behavior differences could be led by gene expression,” said LSU Department of Biological Sciences Assistant Professor Christine Lattin, who is the lead author on the paper published by PLOS ONE today.

Astronomers find ‘gold standard’ star in Milky Way

The star HD 222925 is a ninth-magnitude star located toward the southern constellation Tucana.
Image credit: The STScI Digitized Sky Survey

In our sun’s neighborhood of the Milky Way Galaxy is a relatively bright star, and in it, astronomers have been able to identify the widest range of elements in a star beyond our solar system yet.

The study, led by University of Michigan astronomer Ian Roederer, has identified 65 elements in the star, HD 222925. Forty-two of the elements identified are heavy elements that are listed along the bottom of the periodic table of elements.

Identifying these elements in a single star will help astronomers understand what’s called the “rapid neutron capture process,” or one of the major ways by which heavy elements in the universe were created. Their results are posted on arXiv and have been accepted for publication in the Astrophysical Journal Supplement Series.

“To the best of my knowledge, that’s a record for any object beyond our solar system. And what makes this star so unique is that it has a very high relative proportion of the elements listed along the bottom two-thirds of the periodic table. We even detected gold,” Roederer said. “These elements were made by the rapid neutron capture process. That’s really the thing we’re trying to study: the physics in understanding how, where and when those elements were made.”

Ice-capped volcanoes slower to erupt, study finds

Undergraduate researcher Lilian Lucas, left, and geology professor Patricia Gregg found that additional pressure from thick overlying glacial ice can make volcanic systems more stable and slower to erupt than volcanoes without ice. 
Photo by Fred Zwicky

The Westdahl Peak volcano in Alaska last erupted in 1992, and continued expansion hints at another eruption soon. Experts previously forecasted the next blast to occur by 2010, but the volcano – located under about 1 kilometer of glacial ice – has yet to erupt again. Using the Westdahl Peak volcano as inspiration, a new volcanic modeling study examined how glaciers affect the stability and short-term eruption cycles of high-latitude volcanic systems – some of which exist along major air transportation routes.

The study, led by University of Illinois Urbana-Champaign undergraduate researcher Lilian Lucas, with graduate student Jack Albright, former graduate student Yan Zhan and geology professor Patricia Gregg, used finite element numerical modeling to study the stability of the rock that surrounds volcanic systems – but with a new twist. The team accounted for the additional pressure from glacial ice volcanoes when forecasting the timing of eruptions.

“Volcanic forecasting involves a lot of variables, including the depth and size of a volcano’s magma chamber, the rate at which magma fills that chamber and the strength of the rocks that contain the chamber, to name a few,” Lucas said. “Accounting for overlying pressure from polar ice caps is another critical, yet poorly understood, variable.”

Research breakthrough means warp speed ‘Unruh effect’ can finally be tested in lab settings

SFLORG Stock image

A major hurdle for work at the forefront of fundamental physics is the inability to test cutting-edge theories in a laboratory setting. But a recent discovery opens the door for scientists to see ideas in action that were previously only understood in theory or represented in science fiction.

One such theory is on the Unruh effect. When astronauts in a spacecraft undergo super strong acceleration and see the light of stars stream by, then the Unruh effect is an additional warm glow on top of the streaming light. First predicted by Canadian physicist Bill Unruh, this effect is closely related to the glow from black holes predicted by Stephen Hawking. This is because black holes strongly accelerate everything towards them.

“Black holes are believed to be not entirely black,” says Barbara Šoda, a PhD student in physics at the University of Waterloo. “Instead, as Stephen Hawking discovered, black holes should emit radiation. This is because, while nothing else can escape a black hole, quantum fluctuations of radiation can.”

Similar to how the Hawking effect needs a black hole, the Unruh effect requires enormous accelerations to produce a significant glow. The Unruh effect was therefore thought to be so weak that it would be impossible to measure with the acceleration that can be achieved in experiments with current technology.

Soil Microbes Use Different Pathways to Metabolize Carbon

Credit: Victor O. Leshyk/Northern Arizona University

Much of what scientists think about soil metabolism may be wrong. New evidence from Northern Arizona University suggests that microbes in different soils use different biochemical pathways to process nutrients, respire and grow. The study, published in Plant and Soil, upends long-held assumptions in the field of soil ecology and calls for more investigation and higher-resolution methods to be applied to what has been a black box for the field.

“As ecologists, we generally don’t think about soil metabolism in terms of pathways,” said Paul Dijkstra, research professor of biology in the Center for Ecosystem Science and Society at NAU and lead author of the study. “But we now have evidence that metabolism differs from soil to soil. We’re the first to see that.”

“We’ve learned that biochemistry—more specifically, the metabolic pathways the soil microbiota chooses—matters, and it matters a lot,” said co-author Michaela Dippold, a professor of bio-geosphere interactions at University of Tübingen in Germany. “Our field urgently needs to develop experimental approaches that quantify maintenance energy demand and underlying respiration in a robust way. It’s a challenge to which future soil ecology research will have to respond.”

Study finds cells take out the trash before they divide

MIT researchers have discovered that before cells start to divide, they toss waste products. In this image, the magenta represents DNA, and the green represents a lysosomal marker on the surface of the cells, which is an indicator of lysosomal exocytosis.
Credits: Courtesy of the researchers / Massachusetts Institute of Technology

MIT researchers have discovered that before cells start to divide, they do a little cleanup, tossing out molecules that they appear not to need anymore.

Using a new method, they developed for measuring the dry mass of cells, the researchers found that cells lose about 4 percent of their mass as they enter cell division. The researchers believe that this emptying of trash helps cells to give their offspring a “fresh start,” without the accumulated junk of the parent cell.

“Our hypothesis is that cells might be throwing out things that are building up, toxic components or just things that don’t function properly that you don’t want to have there. It could allow the newborn cells to be born with more functional contents,” says Teemu Miettinen, an MIT research scientist and the lead author of the new study.

Scott Manalis, the David H. Koch Professor of Engineering in the departments of Biological Engineering and Mechanical Engineering, and a member of the Koch Institute for Integrative Cancer Research, is the senior author of the paper, which appears today in eLife. MIT biological engineering undergraduates Kevin Ly and Alice Lam are also authors of the paper.