Ancient DNA pulls back curtain on the Sahara Desert's greener past
CNN —
Picture the Sahara, and an inhospitable landscape of endless sand dunes and barren rock comes to mind.
That's largely the case today, but 7,000 years ago the vast desert was an altogether different place: a verdant world of trees and rivers and home to megafauna such as hippos and elephants.
Over the past decades, scientists have gleaned details of the 'green Sahara.' Now, with the help of ancient DNA from mummified remains, geneticists are figuring out who once lived there.
A long time ago
The mummified remains of a woman buried in the Takarkori rock shelter date back about 7,000 years.
Archaeological Mission in the Sahara/Sapienza University of Rome
The Takarkori rock shelter — situated in southwestern Libya's Tadrart Acacus mountains — offers a remarkable glimpse into the Sahara's greener past.
Archaeologists uncovered the remains of 15 women and children at the site two decades ago.
Initial attempts to extract ancient DNA from the remains fell flat. Cool and constant conditions — the opposite of the extreme temperature swings of today's Sahara — yield the best preserved DNA.
New techniques made it possible to sequence the genome — a complete set of genetic material — of two mummified women. The analysis revealed intriguing information about the ancestry of the Takarkori people and how they adopted a herding way of life.
Explorations
Dark energy is a mysterious force that accelerates the expansion of the universe, and it's thought to represent about 70% of the energy in the cosmos.
New clues from the Dark Energy Spectroscopic Instrument collaboration, known as DESI, suggest dark energy may be behaving in unexpected ways and may even be weakening over time.
The collaboration, now in its fourth year of surveying the sky, has released its latest batch of data. While it's not the final word, the information has space scientists excited.
'We're in the business of letting the universe tell us how it works, and maybe the universe is telling us it's more complicated than we thought it was,' said Andrei Cuceu, a postdoctoral researcher at the Lawrence Berkeley National Laboratory, which manages DESI.
Defying gravity
A SpaceX Falcon 9 rocket with the Fram2 mission astronauts aboard lifts off from Kennedy Space Center in Florida on Monday.
Gregg Nedwton/AFP/Getty Images
A SpaceX Falcon 9 rocket sent four tourists in a Crew Dragon capsule on a polar orbit never attempted before.
Spearheading the Fram2 mission was Malta resident Chun Wang, who made his fortune running Bitcoin mining operations. He paid SpaceX an undisclosed sum for this trip.
Watch a video of the spacecraft's splashdown off California's coast on Friday after Wang and his crewmates — film director Jannicke Mikkelsen, robotics researcher Rabea Rogge and adventurer Eric Philips — spent 3.5 days in low-Earth orbit.
It was the first journey to space for each of the four crew members, who all have ties to polar land exploration.
Meanwhile, NASA's Suni Williams and Butch Wilmore spoke out this week for the first time following a protracted nine-month mission to space. Here's what they had to say.
Dig this
To the untrained eye, stone tools may look like ordinary rocks, but to specialists they have fascinating stories to tell.
Researchers have found stone artifacts crafted in a style closely associated with Neanderthals in East Asia for the first time at a site in southwestern China's Yunnan province.
The discovery, dating back 60,000 to 50,000 years, has puzzled archaeologists, who have come up with competing hypotheses to explain the stone tools.
Perhaps Neanderthals could have migrated east and reached what's now China, or a different species of ancient human possibly made tools uncannily similar to those unearthed in Europe.
Either way, the answer could shake up what's known about human origins during the Stone Age.
Dino-mite
An artist's illustration depicts how herbivorous sauropods (left) and carnivorous megalosaurs would have moved around the same lagoon in what's now the Isle of Skye in Scotland.
Tone Blakesley/Scott Reid
Ancestors of T. rex and their plant-eating prey would have congregated to drink water from a lagoon on what's now Scotland's Isle of Skye, according to an analysis of newly identified dinosaur footprints.
Lead study author Tone Blakesley said he was among a small group that recognized an initial three footprints at the remote site on the isle's Trotternish Peninsula in 2019 when he was a graduate student at the University of Edinburgh.
'It was very exciting,' Blakesley said. Documenting a total of 131 footprints, he used a drone to take thousands of overlapping images of the site before producing digital 3D models of the tracks. They are preserved in 'exquisite detail,' he added.
The wonder
Dive into these remarkable stories.
— The discovery of a mystery king's tomb in Abydos, Egypt, is revealing fresh clues about a long-lost dynasty notoriously missing from records of pharaohs who once ruled the region.
— Scientists sent a container of cooked soybean paste to the International Space Station, where it was left to ferment before returning to Earth as miso. Here's how it tasted.
— An eerie spiral recently lit up European skies, and it's becoming a more common sight.
— Archaeologists excavating a massive tomb in Pompeii unearthed extremely rare, nearly life-size marble statues that shed new light on the power held by priestesses in the ancient city.
Like what you've read? Oh, but there's more. Sign up here to receive in your inbox the next edition of Wonder Theory, brought to you by CNN Space and Science writers Ashley Strickland, Katie Hunt and Jackie Wattles. They find wonder in planets beyond our solar system and discoveries from the ancient world.
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Egypt Independent
06-07-2025
- Egypt Independent
The first genome sequenced from ancient Egypt reveals surprising ancestry, scientists say
CNN — In a long-sought first, researchers have sequenced the entire genome of an ancient Egyptian person, revealing unprecedented insight about the ancestry of a man who lived during the time when the first pyramids were built. The man, whose remains were found buried in a sealed clay pot in Nuwayrat, a village south of Cairo, lived sometime between 4,500 and 4,800 years ago, which makes his DNA the oldest ancient Egyptian sample yet extracted. The researchers concluded that 80 percent of his genetic material came from ancient people in North Africa while 20 percent traced back to people in West Asia and the Mesopotamia region. Their findings, published Wednesday in the journal Nature, offer new clues to suggest there were ancient cultural connections between ancient Egypt and societies within the Fertile Crescent, an area that includes modern-day Iraq (once known as Mesopotamia), Iran and Jordan. While scientists have suspected these connections, before now the only evidence for them was archaeological, rather than genetic. The scientists also studied the man's skeleton to determine more about his identity and found extensive evidence of hard labor over the course of a long life. 'Piecing together all the clues from this individual's DNA, bones and teeth have allowed us to build a comprehensive picture,' said lead study author Dr. Adeline Morez Jacobs, visiting research fellow at England's Liverpool John Moores University, in a statement. 'We hope that future DNA samples from ancient Egypt can expand on when precisely this movement from West Asia started.' Pottery and other artifacts have suggested that Egyptians may have traded goods and knowledge across neighboring regions, but genetic evidence of just how closely different ancient civilizations mingled has been harder to pin down because conditions such as heat and humidity quickly degrade DNA, according to the study authors. This man's remains, however, were unusually well-preserved in their burial container, and the scientists were able to extract DNA from one of the skeleton's teeth. While the findings only capture the genetic background of one person, experts said additional work could help answer an enduring question about the ancestry of the first Egyptians who lived at the beginning of the longest-lasting known civilization. A pottery vessel containing the man's remains was discovered in 1902. Garstang Museum of Archaeology, University of Liverpool Decoding a DNA puzzle Swedish geneticist Svante Pääbo, who won the Nobel Prize in physiology or medicine in 2022 for sequencing the first Neanderthal genome, made pioneering attempts 40 years ago to extract and study DNA from ancient Egyptian remains, but he was unable to sequence a genome. Poor DNA preservation consistently posed an obstacle. Since then, the genomes of three ancient Egyptian people have been only partially sequenced by researchers using 'target-enriched sequencing' to focus on specific markers of interest in the specimens' DNA. The remains used in that work date back to a more recent time in Egyptian history, from 787 BC to AD 23. It was ultimately improvements in technology over the past decade that paved the way for the authors of the new study to finally sequence an entire ancient Egyptian genome. 'The technique we used for this study is generally referred to as 'shotgun sequencing,' which means we sequence all DNA molecules isolated from the teeth, giving us coverage across the whole genome,' wrote study coauthor Dr. Linus Girdland-Flink, a lecturer in biomolecular archaeology at the University of Aberdeen in Scotland, in an email. 'Our approach means that any future researcher can access the whole genome we published to find additional information. This also means there is no need to return to this individual for additional sampling of bone or tooth material.' The man, who died during a time of transition between Egypt's Early Dynastic and Old Kingdom periods, was not mummified before burial because it was not yet standard practice — and that likely preserved his DNA, the researchers said. 'It may have been a lucky circumstance — perhaps we found the needle in the haystack,' Girdland-Flink said. 'But I think we will see additional genomes published from ancient Egypt over the coming years, possibly from individuals buried in ceramic pots.' While Egypt's overall climate is hot, the region has relatively stable temperatures, a key factor for long-term genetic preservation, Girdland-Flink said. That climate, the clay pot used for burial and the rock tomb it was placed in all played a role in preventing the man's DNA from deteriorating, he said. The clay pot was found inside a tomb cut into the rock at Nuwayrat, south of Cairo. Garstang Museum of Archaeology, University of Liverpool Tracing unique ancestry For their analysis, the researchers took small samples of the root tips of one of the man's teeth. They analyzed the cementum, a dental tissue that locks the teeth into the jaw, because it is an excellent tool for DNA preservation, Girdland-Flink said. Of the seven DNA extracts taken from the tooth, two were preserved enough to be sequenced. Then, the scientists compared the ancient Egyptian genome with those of more than 3,000 modern people and 805 ancient individuals, according to the study authors. Chemical signals called isotopes in the man's tooth recorded information about the environment where he grew up and the diet he consumed as a child as his teeth grew. The results were consistent with a childhood spent in the hot, dry climate of the Nile Valley, consuming wheat, barley, animal protein and plants associated with Egypt. But 20 percent of the man's ancestry best matches older genomes from Mesopotamia, suggesting that the movement of people into Egypt at some point may have been fairly substantial, Girdland-Flink. Dental anthropologist and study coauthor Joel Irish also took forensic measurements of the man's teeth and cranium, which matched best with a Western Asian individual. Irish is a professor in the School of Biological and Environmental Sciences at Liverpool John Moores University. The study provides a glimpse into a crucial time and place for which there haven't been samples before, according to Iosif Lazaridis, a research associate in the department of human evolutionary biology at Harvard University. Lazaridis was not involved with the new study but has done research on ancient DNA samples from Mesopotamia and the Levant, the eastern Mediterranean area that includes modern-day Syria, Lebanon, Israel, the Palestinian territories, Jordan and parts of Turkey. The remains are now kept at World Museum Liverpool. Garstang Museum of Archaeology, University of Liverpool Researchers have long questioned whether the Egyptians from the beginnings of the Dynastic civilization were indigenous North Africans or Levantine, Lazaridis said. 'What this sample does tell us is that at such an early date there were people in Egypt that were mostly North African in ancestry, but with some contribution of ancestry from Mesopotamia,' Lazaridis said. 'This makes perfect sense geographically.' Lazaridis said he hopes it's the beginning of more research on Egypt, acknowledging that while mummification helped preserve soft tissue in mummies, the chemical treatments used in the mummification process were not ideal for ancient DNA preservation. 'I think it is now shown that it is feasible to extract DNA from people from the beginnings of Egyptian civilization and the genetic history of Egypt can now begin to be written,' he said. A mysterious burial By studying the man's skeleton, the team was able to determine that he was just over 5 feet tall and between 44 and 64 years old, likely closer to the end of that range — 'which is incredibly old for that time period, probably like 80s would be today,' Irish said. Genetic analysis suggests he had brown eyes and hair and dark skin. And his bones told another tale: just how hard he labored in life, which seems at odds with the ceremonial way he was buried within the ceramic vessel. Indications of arthritis and osteoporosis were evident in his bones, while features within the back of his skull and vertebra showed he was looking down and leaning forward for much of his lifetime, Irish said. Muscle markings show he was holding his arms out in front of him for extended periods of time and carrying heavy materials. The sit bones of his pelvis were also incredibly inflated, which occurs when someone sits on a hard surface over decades. There were also signs of substantial arthritis within his right foot. Irish looked over ancient Egyptian imagery of different occupations, including pottery making, masonry, soldering, farming and weaving, to figure out how the man might have spent his time. 'Though circumstantial these clues point towards pottery, including use of a pottery wheel, which arrived in Egypt around the same time,' Irish said. 'That said, his higher-class burial is not expected for a potter, who would not normally receive such treatment. Perhaps he was exceptionally skilled or successful to advance his social status.' Before the pottery wheel and writing systems were shared between cultures, domesticated plants and animals spread across the Fertile Crescent and Egypt in the sixth millennium BC, as societies transitioned from being hunter-gatherers to living in permanent settlements. Now, the study team wonders whether human migrations were also part of that shift. Additional ancient genomes from Egypt, Africa and the Fertile Crescent could supply answers about who lived where and when. 'This is just one piece of the puzzle that is human genetic variation: each person who ever lived — and their genome — represents a unique piece in that puzzle,' Girdland-Flink said in an email. 'While we will never be able to sequence everyone's genome, my hope is that we can gather enough diverse samples from around the world to accurately reconstruct the key events in human history that have shaped who we are today.' Sign up for CNN's Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more.
See - Sada Elbalad
02-07-2025
- See - Sada Elbalad
Space X Launches Advanced European Weather Satellite
Rana Atef On Wednesday, a SpaceX Falcon 9 rocket launched an advanced European weather satellite. The Falcon 9 lifted off from NASA's Kennedy Space Center in Florida, carrying the MTG-Sounder (MTG-S1) satellite. The rocket's first stage returned to Earth as planned about 8.5 minutes later, touching down on the SpaceX drone ship "Just Read the Instructions," in the Atlantic Ocean. It was the ninth launch and landing for this booster. Among the booster's previous flights were the Fram2 private astronaut mission, the Crew-9 flight to the International Space Station for NASA and a January 2025 launch that sent two private landers toward the moon: Firefly Aerospace's Blue Ghost and ispace's Resilience. read more UAE's Lunar Mission Delayed to Tomorrow Twitter Lifts Trump's Account Ban Scientists Find Evidence Of 10،000 Black Holes Surrounding The Center Of The Milky Way Galaxy Greenhouse In Antarctica Able To Grow Vegetables Without Soil Or Sunlight Moving Over China: U.S. Is Again Home to World's Speediest Supercomputer Technology The 10 most expensive cars in the world Technology Top 10 fastest cars in the world Technology Lasers Could Make Computers 1 Million Times Faster Technology Smart technology taking control of our lives News China Launches Largest Ever Aircraft Carrier Sports Former Al Zamalek Player Ibrahim Shika Passes away after Long Battle with Cancer Videos & Features Tragedy Overshadows MC Alger Championship Celebration: One Fan Dead, 11 Injured After Stadium Fall Lifestyle Get to Know 2025 Eid Al Adha Prayer Times in Egypt Business Fear & Greed Index Plummets to Lowest Level Ever Recorded amid Global Trade War News Flights suspended at Port Sudan Airport after Drone Attacks Videos & Features Video: Trending Lifestyle TikToker Valeria Márquez Shot Dead during Live Stream News Shell Unveils Cost-Cutting, LNG Growth Plan Technology 50-Year Soviet Spacecraft 'Kosmos 482' Crashes into Indian Ocean News "Tensions Escalate: Iran Probes Allegations of Indian Tech Collaboration with Israeli Intelligence"
Egypt Independent
30-06-2025
- Egypt Independent
Humans aren't built to remember everything. 5 tips to remember the important stuff
Editor's note: The podcast Chasing Life With Dr. Sanjay Gupta explores the medical science behind some of life's mysteries big and small. You can listen to episodes here. (CNN) — Most of us are familiar with the frustration of forgetting — whether it's struggling with a word on the tip of the tongue, misplacing important items such as keys or glasses, or even disremembering why you came into a room. How can we do anything but forget — especially in a time in which we are subjected to a firehose of information every waking minute, between our life in the physical world and what comes at us electronically via smartphones, TVs, computers and more? The average American is exposed to an estimated 34 gigabytes — or 11.8 hours' worth — of information every day, Dr. Charan Ranganath wrote in his most recent book, 'Why We Remember: Unlocking Memory's Power to Hold on to What Matters.' That figure came from a 2009 report by the Global Information Industry Center at the University of California, San Diego. 'Last time I looked it up, the estimate increased even more since,' Ranganath told CNN Chief Medical Correspondent Dr. Sanjay Gupta recently on his podcast Chasing Life. Ranganath directs the Dynamic Memory Lab at the University of California, Davis, where he is also a professor of psychology and neuroscience. Far from remembering all this information, he said the science of memory shows that humans are designed to forget. In fact, Ranganath's book references the work of cognitive psychologist George Miller, who concluded in a 1956 paper that we can only keep seven items (plus or minus two) in mind at a time. (Subsequent research, Ranganath wrote, shows the number to be closer to three or four items.) 'I think one of the misconceptions out there … is that we're supposed to be taking everything in that's around us,' he said. 'In fact, our brains really operate on this principle of economy: to get as little information in as possible and to make as much of that information.' You can learn more about the nature of memory by listening to the podcast's full episode here. 'It's all about this economy and being able to use attention as this big filter, to be able to focus on the things that are most important,' he said. 'Sometimes it's the things that you expect, and sometimes it's the stuff that violates your expectations — and that's where there's the most meaning,' he said. 'But it also means that we miss things sometimes, and we end up with frustration because our attention was directed at the wrong place at the wrong time.' Improving memory isn't about trying to stuff more information inside your head. 'The thing that I like to say is: Don't try to remember more, remember better,' Ranganath said. 'Sometimes remembering better means memorizing less.' One way to do so, Ranganath said, is with a process called chunking — or grouping many things into one. We remember the alphabet this way as well as our Social Security number and the names of the Great Lakes (the acronym HOMES for Huron, Ontario, Michigan, Erie and Superior). By grouping these items, you reduce the number of things you have to remember: Instead of 26 separate items, the alphabet becomes one. Similarly, memory athletes — who compete to memorize as many digits of pi as possible or the order of a deck of cards — 'develop strategies that allow them to meaningfully slot the information that they're trying to remember into this larger structure so that 10 things can become one thing,' Ranganath said. What can you do if you struggle with forgetfulness? Here are Ranganath's five tricks to help form memories for events that matter. All you have to is remember to 'call a MEDIC!' he said via email. M is for meaning Attach what you want to remember to something of importance. 'You can remember information like names if you can tie them into information that has meaning to you,' he said. For instance, if you are a fan of Greek mythology, you can link Ranganath's first name, Charan, to Charon, the ferryman of the underworld who, for a price, transports the souls of the dead across the River Styx. 'And (you can) imagine me ferrying people across the river of the dead,' he said. Such vivid imagery can help you remember a name. E is for error Test yourself. Even if you make a mistake, Ranganath said trial and error is one of the best ways to remember something. 'If you're learning a new name or foreign language word, take a guess about what the name could be or guess about the meaning of the word,' he said. When you learn the answer, he said, the brain can 'tweak that memory to make sure it is more closely associated with the right answer and less likely to be associated with competing answers.' D is for distinctiveness Make it pop. 'Just as it's easier to find a hot pink Post-it note on a desk full of yellow notes, it's easier to find memories that have features (that) stand out from other memories,' Ranganath said. For example, 'When you put down your keys, take a moment to attend to a detail like a sound or a unique visual cue,' he said. It will go a long way toward helping you remember where you put them, he said, as you're frantically scrambling to get out the door. I is for importance Take advantage of the fact that the brain has adapted to flag moments that are significant. 'We retain memories for events that are important — in a biological sense,' Ranganath said. 'When we have experiences that are rewarding, scary or embarrassing, chemicals like dopamine, noradrenaline or serotonin are released, promoting plasticity.' These neurotransmitters help cement the experience in your memory a bit more. Curiosity can also play a role. 'We have found that being curious has a similar effect on memory,' he said, noting that curiosity activates 'dopamine-carrying areas of the brain' and promotes learning. 'So, before you learn, get curious about the subject!' he said. C is for context Use your senses to do a little time traveling. 'Our memories for events, or episodic memories, are tied to where and when the event took place,' Ranganath said. 'That's why hearing a song that played during your summer abroad in college or smelling food that your grandmother used to make can immediately transport you back in time.' 'If you are trying to recall a past event, imagine yourself in that place and time — how you felt, what you were thinking about, the sights and sounds of the place — and you'll find yourself pulling up a lot,' he said. We hope these five tips help you remember more and memorize less. Listen to the full episode here. And join us next Tuesday for a new episode of the Chasing Life.
