Connect with us


Neanderthal men stayed near home, while women migrated to mate, DNA evidence suggests



‘It brings them alive in some ways and allows me to think about them in a much more complex way’

Inspecting the tooth unearthed at a cave in the Altai mountains of Siberia, Bence Viola, a paleoanthropologist at the University of Toronto, considered what conclusions he could draw.

It was a “milk tooth,” he said in an interview, a barely worn girl’s premolar that would have fallen out naturally, so this person did not necessarily die here, not like the man whose vertebra and ulna were also found nearby in the same cave.

Genius Dog 336 x 280 - Animated

In all he and colleagues found DNA evidence, in bone fragments and teeth, from more than a dozen individuals.

Research published Wednesday shows that the girl with the tooth and the man with the spine were so closely related they were either parent and child or siblings, but also they had different mitochondrial DNA, which comes from the mother, so they were likely father and daughter.

It is the first time such a close family relationship has been shown across such a vast time scale, more than 50,000 years.

Genetic evidence from the other Neanderthals also showed that the males were more closely genetically related than the females. Two other males, for example, were close maternal cousins of the father, possibly sharing a grandmother.

From this, the research team concludes that young Neanderthal women, not young men, tended to migrate between different social groups, each numbering maybe two dozen individuals.

A photo of one of the teeth that was analyzed after it was found in 2018.
A photo of one of the teeth that was analyzed after it was found in 2018. Photo by Klara Komza

The 13 individual Neanderthals whose DNA the team studied make this far and away the largest ever study of a Neanderthal population, Viola said. The paper published Wednesday in Nature is co-authored with his colleague Svante Pääbo, who just won the Nobel Prize in Physiology or Medicine for related discoveries about the genomes of extinct hominins, especially Neanderthals, and human evolution.

The paper’s lead author is Laurits Skov, a postdoctoral researcher at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.

It is not exactly surprising that people who lived and died close to each other are related. But this knowledge works magic in the mind of an anthropologist, Viola said.

“It makes them much more human, being able to actually show this,” said Viola. “It brings them alive in some ways and allows me to think about them in a much more complex way.”

Once you demonstrate that this adolescent Neanderthal girl lost a tooth at a short-term hunting camp, where she spent time with her father and their small group, butchering the ibex they stalked in the hills or the bison that passed in herds through a narrow valley below, then these people come alive, Viola said, and “almost get faces, which is awesome for me.”

The excavation site.
The excavation site. Photo by Bence Viola

Neanderthals are the closest extinct relatives of humans, and of particular interest to the study of human origins because they are so similar to us, from the genetics to the comparatively large brain.

“If you dressed up a Neanderthal in modern clothes and put him on the subway, you might think he’s kind of an ugly guy, but you would recognize him as just like us,” Viola said.

On the other hand, they are also widely seen as a humanity’s brutish caveman cousin, against whom we obviously stack up better, considering who is still alive in their billions and who is extinct for 40,000 years. Since they were discovered 200 years ago, Neanderthals have reassured humans of their evolutionary specialness.

Over the last 20 years, however, partly due to Pääbo’s genomic research, the Neanderthal’s reputation has improved.

Viola points out people used to think Neanderthals did not have symbolic behaviours like art, music or language. This is turning out to be quite wrong, shown by ornaments and painting.

If you dressed up a Neanderthal in modern clothes and put him on the subway, you might think he’s kind of an ugly guy, but you would recognize him as just like us

How they behaved socially is an abiding mystery, although the evidence suggests it was structured, with patterns similar to contemporary homo sapiens, and variation partly driven by innovations in tools and survival strategies.

This newest research was on the genomes of 13 Neanderthals mostly from Chagyrskaya Cave, dated to more than 50,000 years ago, and two from the slightly more recent Okladnikov Cave, both places thought to be short-term hunting camps. These sites, in southern Siberia’s Altai Mountains, are as far east as Neanderthals are known to have lived. Viola’s general sense of their lives is that they were always on the brink of extinction.

Neanderthal populations in Europe may have been different, however, Viola said, as suggested by evidence from a major Neanderthal site, the Vindija Cave in Croatia.

“Our findings raise questions as to whether the characteristics of the Altai communities are related to their isolated geographical location at the easternmost extremity of the known range of Neanderthals … or whether they are characteristic of Neanderthal communities more broadly,” the paper says.

Source link

Continue Reading


Using atomic clocks in space to solve dark matter mystery – Innovation News Network



A team of international scientists is proposing to send atomic clocks into space to detect and understand enigmatic dark matter.

Dark matter is a mystery that has plagued researchers for decades. This unknown essence represents 85% of all matter in the Universe, and although its effects can be observed, it has not been directly detected. Experts from the University of Delaware, the University of California, and the University of Tokyo are collaborating to solve this longstanding mystery by sending atomic clocks into space.

The research, ‘Direct detection of ultralight dark matter bound to the Sun with space quantum sensors,’ which is published in Nature Astronomy, plans to send two atomic clocks into the inner reaches of the solar system to search for ultralight dark matter that has wavelike properties that may affect the operation of the clocks.

What are atomic clocks?

Atomic clocks tell time by measuring the rapid oscillations of atoms and are already utilised in space to enable the Global Positioning System (GPS). In the future, space clocks could help navigate spacecraft and provide links to Earth-based cocks.

Genius Dog 336 x 280 - Animated

All clocks mark time by using some form of a repetitive process, such as a swinging pendulum. However, atomic clocks use laser technology to manipulate and measure the oscillations of atoms which are extremely fast. For example, a clock based on strontium atoms ticks 430 trillion times per second, and atomic clocks are exceedingly more precise than any mechanical devices.

Historically, atomic clocks can cover the size of a couple of tables, but recent advances in precision and portability mean that some atomic clocks can now fit into a van, with NASA’s Deep Space Atomic Clock being even smaller, at around the size of a toaster.

Nevertheless, different types of clocks, based on much higher frequencies, have been developed over the last 15 years, such as optical clocks that are orders of magnitude more precise and will not lose even a second of time over billions of years.

Marianna Safronova, a physicist at the University of Delaware, said: “We now have portable clocks, and it’s fun to think about how you would go about sending such high-precision clocks to space and establish what great things we can do.

“It is a beautiful synergy between a quantum expert and particle theorists, and we are working on new ideas at the intersection of these two fields.”

Unravelling the mysterious properties of dark matter

The proposed research would send space clocks closer to the Sun than Mercury – an area they believe there is more dark matter to detect. These include atomic, nuclear, and molecular clocks that are currently being developed and are otherwise known as quantum sensors.

Safronova explained: “This was inspired by the Parker Solar Probe, the ongoing NASA mission that sent a spacecraft closer to the Sun than any other spacecraft has gone before. It has nothing to do with quantum sensors or clocks, but it showed that you could send a satellite very close to the Sun, sensing new conditions and making discoveries. That is much closer to the Sun than what we are proposing here.”

The aim of the study is to investigate ultralight dark matter, which the researchers believe could make a huge halo-like region that is bound to the Sun. Ultralight dark matter could cause the energies of atoms to oscillate, which will change how the clock ticks, although this effect depends on the atoms the clock uses. The researchers then monitor the differences in the clocks to look for dark matter.

“It has very specific properties and is a very specific dark matter that is detectable by clocks. What is observable is the ratio of those two clock frequencies. That ratio should oscillate if such dark matter exists,” Safronova said.

She explained that nuclear clocks, which are based on nuclear energy levels rather than atomic energy levels, may be the best clock for this research. She is currently involved in a project to build a prototype funded by the European Research Council.

Adblock test (Why?)

Source link

Continue Reading


Space Atomic Clocks Could Unravel the Nature of Dark Matter – AZoQuantum



Analyzing an atomic clock onboard a spacecraft within the orbit of Mercury and very close to the Sun could be the trick to revealing the nature of dark matter according to a new research article published in the December 5th issue of the journal Nature Astronomy.

Artist’s impression of a space atomic clock used to uncover dark matter. Image Credit: Kavli IPMU.

Dark matter composes over 80% of the mass in the universe, but it has thus far dodged detection on Earth, regardless of decades of experimental endeavors. A core component of these hunts is a hypothesis regarding the local density of dark matter, which establishes the number of dark matter particles moving via the detector at all times and thus the experimental sensitivity.

In a few models, this density can be a lot higher than is typically supposed, and dark matter can become more intense in certain regions than in others.

Genius Dog 336 x 280 - Animated

One vital group of experimental searches is those using nuclei or atoms because these have realized extraordinary sensitivity to signals of dark matter. This is conceivable, in part, because when dark matter particles have extremely small masses, they prompt oscillations in the very constants of nature.

These oscillations, for example the interaction strength of the electromagnetic force or in the mass of the electron, alter the transition energies of nuclei and atoms in foreseeable ways.

An international group of scientists, Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) Project Researcher Joshua Eby, University of California, Irvine, Postdoctoral Fellow Yu-Dai Tsai, and University of Delaware Professor Marianna S. Safronova, recognized the potential in these oscillating signals.

They stated that in a specific region of the Solar System, between the orbit of Mercury and the Sun, the dark matter’s density could be exceptionally large, which would mean extraordinary sensitivity to the oscillating signals.

These signals could be captured by atomic clocks, which work by meticulously measuring the frequency of photons discharged in transitions of various states in atoms. Ultralight dark matter in the region of the clock experiment could alter those frequencies as the oscillations of the dark matter marginally increase and decrease the photon energy.

The more dark matter there is around the experiment, the larger these oscillations are, so the local density of dark matter matters a lot when analyzing the signal.

Joshua Eby, Project Researcher, Kavli Institute for the Physics and Mathematics of the Universe

While the accurate density of the dark matter near the Sun is not established, the scientists debate that even a comparatively low-sensitivity search could deliver crucial information.

The density of dark matter is just constrained in the Solar System by information concerning planet orbits. In the region between the Sun and Mercury, the planet closest to the Sun, there is nearly no constraint. Therefore, a measurement onboard a spacecraft could rapidly expose world-leading restrictions on dark matter in these models.

The technology to test their theory is already present. Eby says the NASA Parker Solar Probe, which has been functioning since 2018 with the help of shielding, has moved closer to the Sun than any manmade craft in history and is at present working within the orbit of Mercury, with plans to travel even closer to the Sun in a year.

Atomic clocks in space are already established for numerous reasons other than hunting for dark matter.

Long-distance space missions, including possible future missions to Mars, will require exceptional timekeeping as would be provided by atomic clocks in space. A possible future mission, with shielding and trajectory very similar to the Parker Solar Probe, but carrying an atomic clock apparatus, could be sufficient to carry out the search.

Joshua Eby, Project Researcher, Kavli Institute for the Physics and Mathematics of the Universe

More from AZoQuantum: Precise Atomic Clock Proves Einstein was Right on Time

Journal Reference

Tsai, Y-D., et al. (2022) Direct detection of ultralight dark matter bound to the Sun with space quantum sensors. Nature Astronomy.


Adblock test (Why?)

Source link

Continue Reading


After lunar flyby, NASA’s Orion spacecraft is set to splashdown on Sunday – Ars Technica



Enlarge / Orion, the Moon, and a crescent Earth on Monday.

The Orion spacecraft swung by the Moon on Monday, flying to within 130 km of that world’s surface as it set course for a return to Earth this weekend.

In making this “powered flyby burn” to move away from the Moon, Orion’s service module performed its longest main engine firing to date, lasting 3 minutes and 27 seconds. After successful completion of the maneuver, NASA’s mission management team gave the “go” to send recovery teams out into the Pacific Ocean, where Orion is due to splashdown on Sunday, during the middle of the day.

Genius Dog 336 x 280 - Animated

By getting into an orbit around the Moon, and back out of it again during its deep space mission, Orion has now completed four main propulsive burns. This completes a big test of the spacecraft and its propulsive service module, which was built by the European Space Agency. Although a boilerplate version of Orion made a flight in 2014, it did so without a service module.

As part of this Artemis I mission, NASA is now three weeks into a 25.5-day test flight of the Orion spacecraft. The goal is to validate the spacecraft’s capabilities ahead of a human flight of the vehicle in about two years’ time, the Artemis II mission.

Orion has met most of its main objectives to date, with only the entry, descent, and splashdown part of its mission ahead of it. The spacecraft’s heat shield must demonstrate its ability to survive reentry at a velocity of 39,400 kph. This big test will come Sunday during a fiery reentry into Earth’s atmosphere.

A minor power issue

So far, Orion’s test flight has gone remarkably well. Typically, with new spacecraft, there are issues with thrusters, navigation, or onboard avionics and more. However, Orion has had no major issues. The only real troubleshooting has involved a problem with power systems on the vehicle.

The issue has occurred with four “latching current limiters” that help route power to propulsion and heating systems on Orion. For some reason, automated controllers on Orion commanded the four current limiters to “open” when no such command was supposed to be sent. “We’re not exactly sure on the root cause of the problem, but teams are doing tests on the ground,” said Debbie Korth, the Orion Program deputy manager, during a briefing on Monday evening at Johnson Space Center in Houston.

Overall, the Orion spacecraft has performed like a champion.
Enlarge / Overall, the Orion spacecraft has performed like a champion.

This system is somewhat like a circuit breaker box in a home, and for some reason four of the breakers were opened when they were not supposed to be. This did not pose a threat to Orion, as there are backup power systems. Had a crew been on board it would have required a minor procedure to account for the problem.

In an interview after the news briefing, Korth said she did not think the glitch would have an impact on the service module that will be used for the Artemis II mission. This hardware is already built and being tested in the United States.

“I think it’s probably too early to say for sure, but ideally we will not want to perturb the Artemis II service module,” she said. “This may very well be something we can handle with software.”

Adblock test (Why?)

Source link

Continue Reading