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Ancient DNA reveals the first Neanderthal family

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Genomic analyses of Neanderthals have previously provided insights into their population history and relationship to modern humans, but the social organization of Neanderthal communities remains poorly understood. To explore the social structure of Neanderthals, an international team led by researchers from the Max Planck Institute for Evolutionary Anthropology sequenced multiple individuals from a remote Neanderthal community in Siberia.

According to the researchers, multiple related persons were found among these thirteen people, including a father and his teenage daughter. The thirteen genomes allowed the researchers to gain insight into the social structure of a Neanderthal community. With 10 to twenty members, they seem to have been a small family, and female migration served as the primary means of connecting the groups.

To explore the social structure of Neanderthals, the researchers turned their attention to southern Siberia, a region that has previously been very fruitful for ancient DNA research – including the discovery of Denisovan hominin remains at the famous Denisova Cave. They focused on the Neanderthal remains in Chagyrskaya and Okladnikov Caves, which are within 100 kilometers of Denisova Cave.

Neanderthals used these sites for a brief period around 54,000 years ago, and many possibly contemporaneous Neanderthal remains have been found in their deposits. The 17 Neanderthal remains successfully recovered by the researchers represent the most Neanderthal remains ever sequenced in a single study.

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The Neandertals at Chagyrskaya and Okladnikov hunted ibex, horses, bison, and other animals that migrated through the river valleys that the caves overlook. They collected raw materials for their stone tools dozens of kilometers away, and the occurrence of the same raw material at both Chagyrskaya and Okladnikov Caves also supports the genetic data that the groups inhabiting these localities were closely linked.

The 17 fossils come from 13 Neanderthal people: 7 males and six women, 8 of whom were adults and 5 of whom were kids or young teenagers. The researchers discovered many so-called heteroplasmies in people’s mitochondrial DNA that people shared. Heteroplasmies are a unique genetic variation that only lasts for a few generations.

Among these remains were those of a Neanderthal father and his teenage daughter. The researchers also found a pair of second-degree relatives: a young boy and an adult female, perhaps a cousin, aunt, or grandmother. The combination of heteroplasmies and related individuals strongly suggests that the Neandertals in Chagyrskaya Cave must have lived – and died – at around the same time.

Laurits Skov, the first author of this study, said, “The fact that they were living at the same time is very exciting. This means that they likely came from the same social community. So, for the first time, we can use genetics to study the social organization of a Neanderthal community.”

There is incredibly low genetic diversity inside this community of Neanderthals, which is compatible with a group size of 10–20 people, which is another stunning discovery. This compares more favorably to the population sizes of critically endangered species on the edge of extinction and is significantly lower than those observed in any ancient or modern human community.

However, Neanderthals didn’t live in completely isolated communities. By comparing the genetic diversity of the Y-chromosome, which is inherited father-to-son, with the mitochondrial DNA diversity inherited from mothers, the researchers could answer the question: Was it the men or the women who moved between communities? They found that the mitochondrial genetic diversity was much higher than the Y chromosome diversity, which suggests that these Neanderthal communities were primarily linked by female migration.

Despite the proximity to Denisova Cave, these migrations do not appear to have involved Denisovans – the researchers found no evidence of Denisovan gene flow in the Chagyrskaya Neanderthals in the last 20,000 years before these individuals lived.

Benjamin Peter, the last author of the study, said“Our study provides a concrete picture of what a Neanderthal community may have looked like. It makes Neanderthals seem much more human to me.”

Journal Reference:

  1. Skov, L., Peyrégne, S., Popli, D. et al. Genetic insights into the social organization of Neanderthals. Nature 610, 519–525

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Rare Mars eclipse by the full moon wows stargazers with occultation (video) – Space.com

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On Wednesday (Dec. 7), skywatchers around the world were treated to a celestial show as the full moon eclipsed Mars in the night sky.

The rare event, known as a lunar occultation, refers to one celestial body — in this case, Mars — appearing to disappear or hide behind another — in this case, the moon. This occultation was particularly noteworthy because Mars was at opposition, meaning Earth was directly between it and the sun, making the Red Planet appear particularly bright in the night sky

Related: See Mars at opposition in these free webcasts tonight (Dec. 8)

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View of the last full moon of 2022 through Christmas lights in San Salvador, El Salvador. (Image credit: Camilo Freedman/SOPA Images/LightRocket via Getty Images)

Last night’s occultation of Mars by the full moon produced some gorgeous images from observers around the world. The Griffith Observatory in California had a great view of the moon and Mars joining up on Dec. 7 and caught a time-lapse of the Red Planet disappearing behind Earth’s celestial companion as seen in the video above.

In addition, skywatchers around the world have been posting gorgeous images of the lunar occultation of Mars on social media, offering a look at one of the year’s most-watched celestial events.

Astrophotographer Andrew McCarthy caught Mars and the full moon (opens in new tab) in a beautiful close-up:

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Spaceflight photographer John Kraus caught a stunning shot of Mars (opens in new tab) as it appeared behind the moon following occultation:

Amateur astrophotographer Tom Williams produced a gorgeous image of the moon and Mars by combining multiple photographs, and offered an explanation of how he made the image (opens in new tab) on Twitter.

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Amateur astronomer and photographer Tom Glenn produced a breathtaking image of Mars (opens in new tab) rising above the moon by stacking 15 different photograph frames.

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Astronomer and science communicator Phil Plait caught Mars creeping behind the moon (opens in new tab) just prior to occultation.

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The lunar occultation of Mars by the full Cold Moon was particularly noteworthy because the Red Planet only appears at opposition every 26 months, so the next opposition won’t occur until January 2025.

Mars was also especially close to Earth during this event, which occurred while the planet was at perigee, or its closest point to Earth in its orbit. The record for closest approach between Mars and Earth was set in 2003 at just 34.8 million miles (56 million kilometers); according to NASA, Mars and Earth won’t be this close for another 265 years, until 2287. 

Editor’s Note: If you snap a great photo of either Mars at opposition or the lunar occultation and would like to share it with Space.com’s readers, send your photo(s), comments, and your name and location to spacephotos@space.com

Editor’s Note: This piece was updated at 4:30 p.m. EST (2130 GMT) on Dec. 8 to indicate that the record for Mars’ closest approach to Earth was set in 2003.

Follow Brett on Twitter at @bretttingley (opens in new tab). Follow us on Twitter @Spacedotcom (opens in new tab) or on Facebook (opens in new tab).  

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NASA Artemis I – Flight Day 22: Orion Spacecraft Continues Its Journey Back to Earth – SciTechDaily

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On flight day 20, Orion captured the crescent Earth in the distance as the spacecraft regained communications with the Deep Space Network following its return powered flyby on the far side of the Moon. The spacecraft will splash down on Sunday, December 11. Credit: <span class="glossaryLink" aria-describedby="tt" data-cmtooltip="

NASA
Established in 1958, the National Aeronautics and Space Administration (NASA) is an independent agency of the United States Federal Government that succeeded the National Advisory Committee for Aeronautics (NACA). It is responsible for the civilian space program, as well as aeronautics and aerospace research. Its vision is &quot;To discover and expand knowledge for the benefit of humanity.&quot; Its core values are &quot;safety, integrity, teamwork, excellence, and inclusion.&quot;

” data-gt-translate-attributes=”["attribute":"data-cmtooltip", "format":"html"]”>NASA

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On day 22 of the 25.5-day Artemis I mission, the Orion spacecraft continues its journey back to Earth. Flight controllers and engineers continue to test the spacecraft and its systems in preparation for future flights with a human crew aboard.

The second part of the propellant tank slosh development flight test was conducted by engineers. This propellant slosh test is specifically scheduled during quiescent, or less active, parts of the mission. Propellant motion, or slosh, in space is difficult to model on Earth because, due to the lack of gravity, liquid propellant moves differently in tanks in space than on Earth.


On flight day 20, Orion approached the Moon ahead of the return powered flyby burn that committed the spacecraft to splashdown on Sunday, December 11. Credit: NASA

For the test, flight controllers need to fire the reaction control system thrusters when propellant tanks are filled to different levels. The reaction control thrusters used are located on the sides of the service module and can be fired individually as needed to move the spacecraft in different directions or rotate it into any position. Each of these engines provides about 50 pounds of thrust. Engineers measure the effect the propellant sloshing has on spacecraft trajectory and orientation as Orion moves through space.

The test was first performed after the outbound flyby burn, and now again after the return flyby burn, to compare data at points in the mission with different levels of propellant onboard. Approximately 12,060 pounds of propellant has been used, which is 215 pounds less than estimated prelaunch, and leaves a margin of 2,185 pounds over what is planned for use, 275 pounds more than prelaunch expectations. The first prop slosh test objective was completed on day eight of the mission as Orion prepared to enter the distant retrograde orbit.


On flight day 20, Orion approached the Moon ahead of the return powered flyby burn that committed the spacecraft to splashdown on Sunday, December 11. Credit: NASA

A few key milestones for Orion remain, including the entry system checkouts and propulsion system leak checks on mission days 24 and 25, respectively.

Orion will travel at around 25,000 mph (40,000 km/h) while reentering Earth’s atmosphere, testing the world’s largest ablative heat shield by reaching temperatures up to 5,000 degrees <span class="glossaryLink" aria-describedby="tt" data-cmtooltip="

Fahrenheit
The Fahrenheit scale is a temperature scale, named after the German physicist Daniel Gabriel Fahrenheit and based on one he proposed in 1724. In the Fahrenheit temperature scale, the freezing point of water freezes is 32 °F and water boils at 212 °F, a 180 °F separation, as defined at sea level and standard atmospheric pressure.&nbsp;

” data-gt-translate-attributes=”["attribute":"data-cmtooltip", "format":"html"]”>Fahrenheit (2,800 degrees <span class="glossaryLink" aria-describedby="tt" data-cmtooltip="

Celsius
The Celsius scale, also known as the centigrade scale, is a temperature scale named after the Swedish astronomer Anders Celsius. In the Celsius scale, 0 °C is the freezing point of water and 100 °C is the boiling point of water at 1 atm pressure.

” data-gt-translate-attributes=”["attribute":"data-cmtooltip", "format":"html"]”>Celsius) – approximately half the temperature of the surface of the sun. The heat shield is located at the bottom of the Orion capsule, measuring 16.5 feet (5 meters) in diameter, and sheds intense heat away from the crew module as Orion returns to Earth. The outer surface of the heat shield is made of 186 billets, or blocks, of an ablative material called Avcoat, a reformulated version of the material used on the Apollo capsules. During descent, the Avcoat ablates, or burns off in a controlled fashion, transporting heat away from Orion. Learn more about Orion’s heat shield in the Artemis I reference guide.


Artemis All Access is your look at the latest in Artemis I, the people and technology behind the mission, and what is coming up next. This uncrewed flight test around the Moon will pave the way for a crewed flight test and future human lunar exploration as part of Artemis. Credit: NASA

On Thursday, December 8 at 5 p.m. EST, NASA will host a briefing to preview Orion’s return scheduled for Sunday, December 11 and to discuss how the recovery teams are preparing for entry and splashdown. The briefing will be live on NASA TV, the agency’s website, and the NASA app.

Watch the latest episode of Artemis All Access (video embedded above) for a look back at recent mission accomplishments and a preview of splashdown, including parachute information.

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Discovery Of World's Oldest DNA Breaks Record By One Million Years – Forbes

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Microscopic fragments of DNA were found in Ice Age sediment in northern Greenland. Using cutting-edge technology, researchers discovered the fragments are one million years older than the previous record for DNA sampled from a Siberian mammoth bone.

The discovery was made by a team of scientists led by Professor Eske Willerslev and Professor Kurt H. Kjær. Professor Willerslev is a Fellow of St John’s College, University of Cambridge, and Director of the Lundbeck Foundation GeoGenetics Center at the University of Copenhagen where Professor Kjær, a geology expert, is also based.

“A new chapter spanning one million extra years of history has finally been opened and for the first time we can look directly at the DNA of a past ecosystem that far back in time,” so Professor Willerslev commenting the discovery.

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“DNA can degrade quickly but we’ve shown that under the right circumstances, we can now go back further in time than anyone could have dared imagine.”

Professor Kjær adds that “the ancient DNA samples were found buried deep in sediment that had built-up over 20,000 years. The sediment was eventually preserved in ice or permafrost and, crucially, not disturbed by humans for two million years.”

The incomplete samples, a few millionths of a millimeter long DNA strings, were taken from the København Formation, a sediment formation almost 100 meters thick deposited in the shallow area of a fjord in Greenland’s northernmost point. The climate in Greenland at the time of sedimentation was between 10 to 17 degrees warmer than today, sustaining an ecosystem with no present-day equivalent, resembling a mix of temperate forest and mixed-grass prairie.

Detective work by 40 researchers from Denmark, the UK, France, Sweden, Norway, the U.S. and Germany, unlocked the secrets of the fragments of DNA. The process was painstaking – first they needed to establish whether there was DNA hidden in the sediment, and if there was, could they successfully detach the DNA from the mineral grains – like clay particles and quartz crystals – to examine it? The answer, eventually, was yes. The researchers compared every single DNA fragment with extensive libraries of DNA collected from present-day animals, plants and microorganisms.

The scientists discovered evidence of animals, plants and microorganisms including reindeer, hares, lemmings, birch and poplar trees. They even found that Mastodon, an Ice Age elephant, roamed as far as Greenland before later becoming extinct. Previously it was thought the range of the species did not extend from its known origins of North and Central America.

Some of the DNA fragments were easy to classify as predecessors to present-day species, others could only be linked at genus level, and some originated from species impossible to place in the DNA libraries of animals, plants and microorganisms still living today.

The findings have opened up a whole new period in DNA detection. Thanks to a new generation of extraction and sequencing equipment, researchers will be able to locate and identify extremely small and damaged fragments of genetic information in sediments considered previously unfit for DNA preservation.

“DNA generally survives best in cold, dry conditions such as those that prevailed during most of the period since the material was deposited at Kap København. Now that we have successfully extracted ancient DNA from clay and quartz, it may be possible that clay may have preserved ancient DNA in warm, humid environments in sites found in Africa,” Professor Willerslev concludes.

The paper “A 2-million-year-old ecosystem in Greenland uncovered by environmental DNA” is published in Nature. Material provided by the by University of Cambridge.

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