reveals

Hadrian’s toilet reveals a new secret about the durability of Roman concrete

by

One of the best kept secrets of the Roman Empire is What was special about your concrete? so that Agrippa’s Pantheon has been there for 2,000 years (and what remains). From time to time science and archeology believe you have discovered the secret and for example, a button: this half-finished work in Pompeii left clues. We have found the umpteenth attempt to explain why concrete is no longer made like it used to be in an emperor’s toilet. The discovery. To date the explanation for the resistance of Roman concrete is in the reaction between lime and volcanic ash (a pozzolanic reaction), but a new study adds one more ingredient to the recipe: natural carbonation and the progressive formation of calcite were also important for this construction material to withstand the passage of time so well. In addition to the ingredient, the curious thing is where they took the sample from: from the concrete collector located under one of the seats of one of the common latrines in the western complex of the Canopus, in Hadrian’s Villa in Tivoli. From a toilet. Why is it important. Because beyond the pozzolanic reaction, what really holds concrete together over the centuries is calcite. So the formation of calcite over centuries also helps the structures of these latrines to remain standing two millennia later. Knowing this mechanism opens the doors to the design of modern cements that are more durable. Context. Before we thought that all the merit fell on the reaction between the lime and the ash and be careful, that explanation is still valid, but it is not the only one. Furthermore, previous research such as this MIT study from 2023 pointed out that the white fragments of lime present in the concrete were proof that the Romans used a “hot mix” technique, which gave this construction material the ability to self-heal when cracks appeared. In detail. From 3D images, the team rebuilt in detail the internal composition of the material and what chemical processes it underwent over the centuries. Thus, they verified that calcite was formed through a slow reaction between lime, humidity and carbon dioxide in the air (carbonation) and that mineral progressively filled cracks and pores, making the concrete denser and blocking the passage of potentially harmful substances or even water. The volcanic rock fragments also reacted with the lime in the edge area, which strengthened the bond. Yes, but. The main limitation of this study is that it is based in a single sample from an indoor environment, so the conclusions obtained cannot be directly extrapolated to other Roman concretes studied outdoors or in marine environments, where Different self-repair mechanisms have been described with salt water. We will have to wait for the results to be replicated in other samples and sites before reaching a general conclusion. In Xataka | Almost 2,000 years ago a Celtiberian soldier visited the most remote frontier of the Roman Empire. Then he returned to Soria with a souvenir In Xataka | The latest victim of mass tourism (and perhaps Game of Thrones): Hadrian’s Wall Cover | Jl FilpoC and Mineralized carbonates contribute to the millennial durability of Roman concrete. Advanced Science

A study reveals that we no longer know how to say “I don’t know”

by

I notice that it is increasingly difficult for us to say “I don’t know.” Maybe it is one of the most honest acts that a person can do and, on the other hand, with the arrival of AI and with all the information at our disposal, it seems that we are losing that habit in conversations. a study He wanted to put some data on the table regarding the subject. And the conclusion reached by a group of researchers from different universities in Paris, Rome and Milan, by bringing together 3,100 participants, has been that having access to an AI, even if it gives wrong answers, pushes people to stop recognizing the limits of their own knowledge. I know everything. Recognizing that we don’t know something is more useful than we think, since it is a mental skill that prevents us from acting guided by false beliefs. The authors of the study they call her “suspension of judgment”, that is, the ability to stop before responding when there is uncertainty. As AI assistants sneak into more and more aspects of our lives, the research, signed by Chiara Marcoccia (École Normale Supérieure of Paris), Walter Quattrociocchi (Sapienza University of Rome) and Valerio Capraro (University of Milan-Bicocca), wanted to verify if the simple presence of these chatbots it alters the moment when we decide that we already know enough to answer. The experiment. To isolate the effect, the team purposely designed questions that were almost impossible for an AI to get right, with very specific visual details from movies, such as the color of the kit in ‘I Want to Be Like Beckham’ or the vehicle a character drives in ‘Like Cat and Mouse’. This is data so specific that it barely appears on the internet, so the model used in the experiment (Step 3.5 Flash) almost always failed. Participants could ask the AI ​​if they wanted, but they also always had the option of leaving the question blank or admitting they didn’t know the answer. Figures. In the group that did not have access to any assistant, 44% of the participants admitted not knowing the answer when appropriate. Among those who could ask AI for help, that percentage plummeted to 3%, according to collect the study. Furthermore, the proportion of correct answers also fell, from 27% to 9%. That is, people answered more questions, but they got much less right. The most striking thing is that, despite making more mistakes, the participants felt more confident, since according to the study, their confidence in the answers went from 30% to 76%, almost double. What if there is money at stake?. The researchers suspected that paying for getting it right (and penalizing for getting it wrong) might correct the problem. It did indeed help, but very little, because with financial incentives, the willingness to admit that they did not know the answer rose from 3% to 8%, and the correct answers went from 9% to 16%. Interestingly, the authors themselves expected the effect of AI to be weakened by money, but their data did not confirm this. And the pull towards trusting the machine turned out to be practically independent of the economic incentive. Boundaries. Capraro, co-author of the study, explained told The Register that people “became much worse” at their performance, being only one-third accurate than the non-AI group, but ended up “twice as confident” in their own answers. For the researcher, this ability to say “I don’t know” represents neither more nor less than “the recognition of the limits of our own knowledge.” On the other hand, Capraro was especially concerned about the effect that this phenomenon can have on children. According to declared In the middle, adults “already have formed critical thinking” before the massive arrival of these tools, but children who grow up using AI from the beginning “run the risk of never developing that basic ability to question an answer.” Cover image | Solen Feyissa and Dylan Gillis In Xataka | Meta warns: “We have been building infrastructure for humans for 20 years, we may have 20 months to rebuild it for agents”

A new study reveals its crucial role in memory consolidation

by

The nap is an appointment that many people have during the afternoon and that is very difficult to leave aside. For decades, this practice has oscillated between being a purely Mediterranean cultural trait and a productivity “hack” repeated ad nauseum. However, taking a short break during the day is not a luxury for some, but is a top-level brain maintenance mechanism. They have studied it. To prove exactly why napping is so beneficial, a study chose to investigate the effects it has on the brain. Their objective was none other than to check if a short period of sleep could trigger the same ‘brain cleansing’ processes that occur during sleep. And the answer is a resounding yes. Neuronal “saturation”. To understand the impact of the study, you must first understand the synaptic homeostasis hypothesis. This tells us that since we wake up, our brain processes information non-stop and each stimulus and each new piece of information strengthens the connections between our neurons. A classic example may be in a student who is trying to learn an opposition syllabus. The problem is that this continuous increase in synaptic strength consumes a lot of energy and takes up physical and metabolic space. The really important thing here is that there comes a point in the day when the brain is “saturated” since cortical excitability is so high that the ability to consolidate new information plummets. This is when the system literally asks us to “reset” in order to continue processing the information to which we are exposing it. How have they seen it? The experiment involved 20 young adults, and rather than relying on subjective surveys of “how rested they felt,” the team turned to direct physical measurements. They used Transcranial Magnetic Stimulation to measure corticospinal excitability and electroencephalograms to monitor brain activity. Once the method was in place, it was decided to evaluate the patients first between 1:15 p.m. and 2:15 p.m., after spending a good amount of time awake, and then after taking a 45-minute nap. The results. They clearly saw with these analyzes that the brain cleaned its neurons and irrelevant connections were weakened, lowering the “background noise” and returning the system to an optimal state to create new connections again. But also, by releasing this charge, the neurons recovered a very high capacity to induce Long Term Enhancement. That is, the brain was once again in optimal conditions to create a lasting memory. The 20 minute rule. A mantra that can be heard is that the optimal nap should be twenty minutes long in order to regain alertness quickly. However, this study indicates that, to achieve a true architectural recalibration of plasticity in the cerebral cortex, entering into a cycle of about 45 minutes allows the memory consolidation mechanisms to act in depth. In this way, taking a break during the day is not at all something ‘lazy’ but rather it is a brain recalibration system that will allow us to increase our productivity when working or studying. In Xataka | In Spain we have glorified the long nap. In scientific studies they have a different opinion on the matter.

SpaceX’s IPO reveals the extent to which Gulf money is behind the US AI boom

by

SpaceX just starred largest IPO on Wall Streetone that is going to make Elon Musk the first billionaire in history. For a company to go public means that many details are made public and among all the paperwork one thing has become clear: Saudi Arabia and the United Arab Emirates are financing the AI ​​boom, and it is not in exchange for anything. what’s happening. As of June 12, SpaceX is listed on the Nasdaq with a valuation of $1.75 trillion (with a B, the largest in history). As they point out in Rest of Worldthis IPO has not only served to break records, it has also revealed details that until now were private. The S-1 form, also known as the ‘prospectus’, has made it visible that the company plans to raise $75 billion, of which at least $5 billion will come from the Saudi Arabian Public Investment Fund. Why is it important. SpaceX’s IPO has made deals public that until now were private and consolidates Middle Eastern investors as key investors in American technological development. This operation is part of a broader strategy in which they have allocated tens of billions to American AI. We see this in examples such as Humain, the state-owned AI company in Saudi Arabia, which put 3,000 million in xAI at the beginning of the year and that after the merger They have become shares of SpaceX. Also with MGX, a technology investment fund based in Abu Dhabi, which has stakes in OpenAIAnthropic and of course SpaceX. What do they get in return?. The money they are putting in is tied to a series of demands, the main one being the obligation to build AI infrastructure in their territory. With these agreements they are moving all associated economic activity (employment, tax revenue…) outside the US, in addition to achieving the transfer of technological knowledge. At a geopolitical level, having critical infrastructure protects them from possible crises. It is something that is already happening: Musk’s ties to the Middle East. Capital from the region has been key in SpaceX’s IPO, to the point that Gulf sovereign funds took priority on the lists subscription. Trust between the tycoon and Middle Eastern investors has been building since, in 2011, Saudi Prince Alwaleed bin Talal invested $300 million in what was then Twitter. When Musk bought the social network in 2022, Alwaleed refused to liquidate his share, aligning himself with Musk. Later, xAI merged with SpaceX, so that investment became shares in the company. It is estimated that, after the operation, Alwaleed’s personal fortune has reached 27 billionbecoming one of the big winners. Image | Xataka with Gemini In Xataka | Saudi Arabia had 38 billion dollars ready to become the great power of video games. And then Iran appeared

a macro study reveals the exact heart rate to minimize the risk of stroke

by

Nowadays we monitor our vital signs, such as heart rateon the wrist itself thanks to smartwatches and activity bracelets that constantly tell us how many beats per minute our heart beats at rest. This information is vital, since traditionally it is believed that having an excessively high number is an indication that something bad is happening in the heart. The middle point is the best. In medicine, both due to excess and scarcity, we can find a scenario that is pathological, and that is why, although we relate high heart rate as something very negative, we must keep in mind that having them excessively low It is not always positive. This is the main conclusion of a pioneering research presented at the European Stroke Organization Conference, and although it has yet to undergo review, its foundations are extraordinarily solid, based on the analysis of 460,000 participants over 14 years. Crossing data. Of all these people analyzed, the researchers were especially interested in their medical histories and the diseases they presented, highlighting the registration of a total of 12,290 cases of stroke during the decade and a half of follow-up. But what is truly important here is when these records were crossed with the resting heart rate data of the participants, discovering a very clear pattern by showing a risk graph in the shape of a ‘U’ and not a straight line. Its meaning. The fact that a graph with this shape has been generated tells us that the optimal heart rate level is between 60 and 69 beats per minute, since these people were the ones with the lowest risk of suffering from a stroke. The problem is that, when the heart rate at rest exceeds 90 bpm, the risk of suffering a stroke increases by up to 45%, both ischemic and hemorrhagic. But in the case of having excessively low heart rate, the risk also increases, so we cannot be completely calm if we have 50 bpm at rest. Atrial fibrillation. Until now, medicine was very clear that severe arrhythmias such as atrial fibrillation They were determining risk factors for suffering a stroke. But now this study adjusted the data specifically to separate people with and without atrial fibrillation, showing that resting heart rate is, on its own, an independent prognostic marker. Because? Although this study gives us a lot of information, the reality is that previous medical literature already offered a fairly rigorous explanation as to why a low or high heart rate had implications for strokes. In this case, an excessively low frequency can alter cerebral hemodynamics, causing blood to pass too slowly through the brain, and facilitating the formation of thrombi in certain contexts, especially when there are more risk factors. On the other side of the scale, when the frequency is chronically high, we have the layer of our blood vessels exposed to blood flow, exposed to constant mechanical stress that favors inflammation, hypertension and vascular damage, as has been shown in previous studies. Preventive medicine. These findings are good news for patients, especially older patients, since it is a new parameter that can predict the possibility of something as serious as a stroke occurring. This allows, especially in primary care, to better control the heart rate and not miss when it goes too fast or too slow, since the consequences can be fatal. Images | freepik In Xataka | We cannot predict a stroke, but we can avoid its main risk factors: reducing the danger is in our power

A new study reveals how they manage to avoid cancer

by

Reaching 100 years old is a statistical feat, but do it while avoiding diseases as serious as cancer or surviving a serious infection is almost a superpower. For decades, science has been asked what makes centenarians biologically special to reach where few reach, and the clearest answer we have right now is that your immune system ages at a completely different rate than the rest of us mortals. The passage of time. As we age, our body deteriorates at a more or less rate depending on how much we have taken care of it with the lifestyle we have wanted to follow. But something that cannot be skipped is the generation of a low-grade chronic inflammation called ‘inflammation‘ which is the perfect breeding ground for cells to deteriorate, cardiovascular problems and tumors to appear. An exception. But as a recent review points out published in Nature With Spanish participation, it has been seen that centenarians have an extremely efficient system for “cleaning” damaged or senescent cells before they cause problems, something that is very efficient in young people, but becomes less so with the passage of time. But in addition, compared to the impoverishment of the intestinal flora common in old age, centenarians preserve a spectacular microbial diversity, also lacking the pro-inflammatory obesity that affects a large part of the population. But not everything is natural genetics, since the habits one follows and the environment in which one has lived shape part of the genetics by activating or deactivating genes, protecting them from accumulated damage. The paradox of cancer. One of the most fascinating data that medical research reveals is the relationship between centenarians and cancer. Although the risk of suffering from tumors increases with age as more genetic errors accumulate, when the 100-year barrier is exceeded, the curve falls sharply. This means that the incidence of cancer in people over the age of one century is less than 4%. And again the question is: why? Here, science suggests that centenarians have very high selective cytotoxicity, that is, cells with problems inside are destroyed before they get worse. Here the protagonists are the immune cells that maintain relentless anti-tumor surveillance, eliminating malignant cells with the efficiency of a young adult, but maintaining a high tolerance towards their own healthy tissues to avoid autoimmune diseases such as the famous rheumatoid arthritis that is quite common in older people. We are moving forward. The study does not remain only in the laboratory, but compiles evidence about the “real world” such as the famous ‘Blue Zones’ of Okinawa (Japan) where great longevity among its inhabitants stands out. Here the autopsies on the corpses indicated that their coronary arteries were obstructed by age but that they had only suffered massive fatal heart attacks. Here the body had found ways to adapt and survive. During the worst waves of COVID, there have also been cases of centenarians in residences who managed to survive the virus even without being vaccinated. This fits with the published data in 2023 by Nature Aging on supercentenarians in Boston, who revealed an “elite” immune system, trained by a lifetime of environmental exposures that formed a profile highly resilient to infections. For the future. Although genetics are important, what we can control much better are lifestyle habits and their effect on how certain genes are expressed. In this way, it is about investigating the people who survive the longest with the aim of ‘copying’ what they do to find the Holy Grail of longevity. Images | freepik In Xataka | The promise of 120 years is dismantled: biology sets a life ceiling that is quite difficult to break

The spike in Google searches after the 2024 eclipse reveals that we continue to ignore science

by

It has been known for a long time that It is not healthy to look directly at a solar eclipse. It is said that Socrates himself I already recommended looking at it reflected in the waterbut never directly. However, human beings have a fairly significant tendency to ignore scientific recommendations. This is possibly the reason why in 2024, after an eclipse in the United States, Google searches for the phrase “my eyes hurt” had a very abrupt peak. The time and place coincide. That peak of searches took place on April 8, 2024 at 3:00 p.m. Eastern Time. Just at that moment a solar eclipse was occurring whose strip of totality crossed from Mexico to Canada, passing through the United States. The states where the most searches were carried out were Vermont, Arkansas, Michigan, Ohio and Indiana, all of them immersed in the path of the eclipse. Eclipse retinopathy. When looking directly into sunlight, the retina can suffer serious damage. The condition that occurs is known as eclipse retinopathy and causes symptoms such as photosensitivity, blurred vision and headache. Vision can be affected for months or even permanently in the most severe cases. For this reason, no matter how much it may seem like the sun is covered, we must look at it with adequate protection. No sunglasses or x-rays. We have all heard at some point that it is safe to look at an eclipse through an x-ray or a photo negative. However, this is a myth that can be very dangerous. Sunglasses are not safe either. Generally, These are prepared to filter approximately 99.9% of solar ultraviolet radiation.. However, in the event of an eclipse, in which we look directly at the sun, this protection is needed, added to a filter of 99.999% of visible sunlight. It is necessary to use special eclipse glasses, always with filters approved by the competent authorities. Be careful with binoculars and telescopes. We should also not look directly through telescopes or binoculars without using filters. These are placed outside the lens and protect our retinas from solar radiation when we look through them. If none of this seems right to us, we can always resort to a pinhole camera, which reflects the image of the eclipse on another surface. Something like what Socrates advised about looking at the reflection in the water. It is important to use approved glasses You shouldn’t even look at a total eclipse. When the eclipse is total, the Sun is completely obscured. At that point, we might feel safe without protection. The problem is that it is not easy to calculate the exact moment in which the eclipse will begin to dissolve and with just a little bit of light, just when the Sun begins to reappear, we can damage our retinas. It is important to use protection from the beginning. It wasn’t eclipse retinopathy. In reality, the symptoms of eclipse retinopathy They usually appear several hours after the event. Interestingly, eye pain is not one of these symptoms. Therefore, what all those people were looking for was due to another reason. When we look at the sun, we usually experience a blink reflex that forces us to look away. However, with a solar eclipse the brightness is dimmed enough for this reflection to disappear. As a consequence, we can comfortably look at the Sun and keep our eyes fixed, without blinking. That’s what can make our eyes hurt or feel a burning sensation. Specifically, that is not dangerous. Still, those Google searches show that many people were worried. Many of them may not have used protection and regretted it. Ready for August. Next August 12 we will have the first of the eclipses that make up the Iberian Trio. Many people have already bought tickets to travel to some of the points in the totality zone. There are even those who have gotten tickets for one of the many festivals that will be celebrated for this reason. Whatever plan we choose, the important thing is protection. Maybe, even if we protect ourselves, there will be a peak in Google searches, but it better be because we don’t blink for a while and not because we have really damaged our retinas. Image | Magnific/NASA | POT In Xataka | The trio of eclipses that await Spain on the horizon: an unprecedented and historic chain between 2026 and 2028

the study that reveals its birth in an isolated corner of the galaxy

by

2025 was the year of 3I/ATLAS, the third interstellar visitor that telescopes have been able to capture prowling the Earth. From the beginning it was considered that it could possibly be much older than the other two, Oumuamua and 2I/Borisov. However, there were many unknowns about its origin. Now, thanks to a recently published study by scientists at the University of Michigan, we have much more data on the matter. A visitor from a cold and distant place. According to observations made from the ALMA Observatoryin the Atacama Desert (Chile), 3I/ATLAS formed in a cold and isolated corner of our galaxy, before definitively integrating into its own solar system. The key is in deuterium. The observations that led to this recent study were made between October and December 2025. Several telescopes focused their attention on our interstellar visitor to observe the water on its surface and observed something striking: it had very high levels of deuterium. This is an isotope of hydrogen, somewhat heavier than the most abundant on Earth. In astronomy the deuterium/hydrogen ratio is used to estimate the age of objectssince it has been observed that the more primitive they are, the more deuterium they have. But this proportion also helps to know the temperature at which they were formed. A reaction without turning back. In the cold gas clouds in which stars form, the most abundant molecules They are hydrogen, followed by carbon monoxide (CO). Hydrogen participates in something known as deuteron-proton exchange reactions, where hydrogen protons and deuterium isotopes react with each other, forming something known as deuterated hydrogen. This is the reaction: H3+​+HD⇌H2​D++H2​ CO can compete with this reaction, making it less efficient. However, when it is very cold, the CO freezes into dust grains and cannot react. On the other hand, the deuteration reaction can occur in both directions (hence the two arrows), but if it is cold there is not enough energy to produce it backwards. All the hydrogen with deuterium that is formed accumulates. a lonely star. The fact that 3I/ATLAS occurred in such a cold environment may indicate that it possibly originated around a solitary star. If there had been other stars forming around it, it would be much hotter. Very far away now. Today, that interstellar visitor is near Jupiter, preparing to leave our solar system. It can only be observed with a few instruments. Luckily, he came to our neighborhood long enough to give us a lot of valuable information. Why is it useful information?. We already have a lot of data about 3I/ATLAS. For example, its core measures between 440 meters and 5.6 kilometers. Also that it moves at 220,000 km/h. Now, in addition, we know that it originated in an extremely cold environment, about 11,000 million years ago. This helps us understand the conditions of primitive planetary formation much better. As they always say, to know where we are going, it is very important to understand where we come from. There’s nothing like a visitor from a place far, far away to give us the pieces we need to understand it. Image |NSF/AUI/NSF NRAO/M.Weiss In Xataka | A Harvard astronomer has accused NASA of hiding 3I/ATLAS images. has an explanation

Most complete geological map reveals billions of years of impacts and volcanism

by

We have been talking for years not about landing, but about colonize Mars (above all, Elon Musk), but with Artemis II making history and the Orion ship just splashed down After the first manned mission to the Moon in more than 50 years, the old moon has returned to the forefront. Four astronauts have just photograph it up close and leave us with our mouths open. But the Moon is much more than a satellite full of craters: each of those craters tells a story of billions of years. At this moment when our satellite has hit us again, we rescue geological cartography most complete overview ever published. It is the unified geological map of the moonprepared in 2020 by the United States Geological Survey combining data from the lunar reconnaissance orbiter missions (LRO) from NASA and Kaguya from the Japanese Space Agency. The good thing is that although you can see a general sample, you can also download it to have a greater level of detail, since it is at a scale of 1:5,000,000 and derived from six digitized geological maps. Visually, this world map draws attention both for the number of craters and for the shades chosen to color it. The choice of color is not casual or ornamental, but rather each color represents a type of terrain with a specific age and origin. So, at a glance you know whether you’re looking at an ancient lava plain, a recent crater, or the original crust from 4 billion years ago. Without the colors, everything would be a gray mass of craters impossible to distinguish. The moon is full of secrets and this map provides information in abundance to discover them. The unified geographic map of the moon Fragment of the unified geological map of the Moon, scale 1:5M. Via: USGS The moon has five geological eras: Pre-Nectarian, Nectaric, Imbrian, Eratosthenic and Copernican, which range from 4,000 million years ago to today. How to differentiate them on the map? Because they go from purple and orange for the oldest to green and pink for the youngest. All that is seen is the fossilized record of its turbulent youth because it has been “geologically dead” for almost 3,000 million years, but it had a turbulent past as evidenced by its orography. The moon offers a striking visual dichotomy between the highlands (in reddish tones and saturated with craters) and the seas, which are the large dark spots. Of course, they don’t have any water. They are actually basaltic lava plains that filled huge impact basins about 3,000-4,000 million years ago. It is, in short, what we see from Earth. The clear, cratered areas constitute the original crust and are much older. The most characteristic thing about the Moon to the naked eye are the craters, which are something like scars that witness the passage of time: the more softened, diffuse and even buried it appears on the map, the older it is. On the contrary, the sharper, brighter and surrounded by bright rays, the younger. “Lightning bolts” are bursts of dust and rock launched after impact and can extend for many kilometers. There is two especially spectacular craters on the map: Tycho and Copernicuswhose rays cross hundreds of kilometers and are geologically very recent. The part of the Moon that we never see from Earth and that arouses so much curiosity in us (there is a project to install a radio telescope there) is its hidden side: there are almost no blue spots there. And while the visible side is rich in lava plains, the hidden side is a highland fortress, much more rugged and with a significantly thicker crust. Map At its south pole is the basin South Pole-Aitkenthe largest known impact scar in the entire Solar System, with 2,500 km in diameter and 8 km deep. Precisely that area where there are shadow craters science hopes to find water frost. This geological imbalance between both sides suggests that the Moon is asymmetric inside, a mystery that is also on the table of the scientific community. In Xataka | The Earth’s seabed has always been a mystery: an amazing 3D map reveals it in unprecedented detail In Xataka | Astronomers have stitched together 10,000 images from the Webb telescope to make the largest map of the universe. Something doesn’t fit Cover | USGS, NASA

The genome of a Siberian Neanderthal reveals how they lived on the edge of the abyss

by

The Denisova Cave, nestled in the cold Altai Mountains of Siberia, continues to be one of the greatest treasures for world paleonthropology, since it brings together a large number of samples that enrich our history. One of the latest discoveries points to how they were organized and they lived Neanderthal populations in this remote Asian region. Something they have done from the genome of a Neanderthal man from 110,000 years ago. How it was done. The protagonist of this new research published in PNAS is a bone fragment named D17 that was found in these Asian mountains. But in light of previous studies, this team has managed to greatly refine the precision of sequencing, achieving an astonishing 37-fold coverage. This in genomics means that each “letter” of your DNA has been read 37 times, ensuring that the genome we are looking at is extraordinarily precise and not plagued by the degradation errors typical in such old samples. The result. When comparing the D17 genome With other fossils, scientists were in for a surprise, since this individual was directly related to another Neanderthal from the same cave, known as D5, who lived about 120,000 years ago. Despite being separated by 10,000 years of history, the two shared a close genetic link. This tells us something fundamental about Denisova Cave, as it was not a fixed settlement or permanent Neanderthal “city.” Rather, it acted as a recurring base camp or historical refuge to which closely related groups returned from generation to generation, maintaining an unusual regional genetic stability. Endogamy. Perhaps most important in this study is the evidence about how the population was structured. Here D17’s genome shows the genetic scars of living in a very empty world, as Neanderthal populations were tiny and incredibly dispersed. And it is no wonder because we are talking about groups of 50 individuals. This lack of other nearby groups with which to reproduce forced the Altai Neanderthals to crossing paths between close relatives for millennia. The problem with all this is that, being such small populations, the genetic changes were fixed quickly, separating them evolutionarily from other Neanderthal populations in Europe at an accelerated rate. A crossroads. If we started this article by mentioning the Denisova cave, logically we must also talk about the Denisovans, which is the other extinct human species discovered there. Here the new genomic analysis of D17 also confirms gene flow with this mysterious species. In both the D17 and older D5 genomes, scientists have found undeniable genetic traces of interbreeding with the Denisovans. This depicts the Denisova cave not only as a recurring refuge for isolated Neanderthal lineages, but as a true prehistoric crucible, a crossroads where two human species met, interacted and left a genetic legacy that today, through the most cutting-edge technology, we are managing to decipher. Images | freepik In Xataka | We had always thought of Neanderthals as “scavengers”: more and more studies point to the opposite

Log In

Forgot password?

Forgot password?

Enter your account data and we will send you a link to reset your password.

Your password reset link appears to be invalid or expired.

Log in

Privacy Policy

Add to Collection

No Collections

Here you'll find all collections you've created before.