Researchers at the University of Copenhagen found that a signaling mechanism in the cells’ ‘antennae’ may help explain why some fetuses develop disease in both the heart and other organs. About two of every 100 babies worldwide are born with congenital heart disease, but the biological processes responsible for these conditions are not fully understood. [...]Changing what you eat may begin reshaping how your genes behave in as little as a few weeks, even though your DNA itself remains unchanged. In a randomized clinical trial, researchers found that healthy adults who followed a vegan diet for one month developed changes in chemical markers attached to their DNA. Compared with participants [...]A study suggests that genetic factors may explain why LDL cholesterol rises sharply in some people who follow a low-carbohydrate, high-fat diet. Two people can follow the same low-carbohydrate diet and experience very different changes in cholesterol. One may see little difference, while the other develops a sharp increase in low-density lipoprotein (LDL) cholesterol. New [...]Neanderthals vanished roughly 42,000 years ago, but a piece of their biology appears to be quietly at work in some people today, according to a new study led by scientists from the Max Planck Institute for Evolutionary Anthropology.
The post Neanderthal Gene Still Shapes Muscle and Jaws in Some Living Humans appeared first on Sci.News: Breaking Science News.
Ancient DNA may give some slightly more muscles today.Researchers say breakthrough offers hope for new medicines but also raises urgent biosecurity questions
Scientists have made the first viruses designed by artificial intelligence in a milestone that raises hopes for new medicines but also concerns over how to ensure the technology remains safe.
The viruses are specific kinds known as bacteriophages, which only infect bacteria and are used around the world to treat patients with persistent infections. In lab tests, a cocktail of the AI-designed viruses killed E coli bugs that were resistant to natural bacteriophages.
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© Photograph: Samyukta Lakshmi/Bloomberg/Getty Images
© Photograph: Samyukta Lakshmi/Bloomberg/Getty Images
© Photograph: Samyukta Lakshmi/Bloomberg/Getty Images
New research led by the University of California, Berkeley reveals that beyond Neanderthals and Denisovans, humans interbred with two mysterious ‘ghost’ lineages: one in Africa more than 50,000 years ago, another in Eurasia over 1.7 million years ago.
The post Scientists Find Traces of Two Unknown Archaic Hominins in Human DNA appeared first on Sci.News: Breaking Science News.
Certain gut bacteria were linked to slower or faster biological aging. The communities of bacteria living in the gut may carry clues about how rapidly the body is aging. Researchers at the University of Hawaiʻi at Mānoa found that certain microbial patterns were associated with faster or slower biological aging, adding to evidence that gut [...]By studying a gene associated with congenital heart defects, scientists uncovered a mechanism showing how small reductions in protein levels can disrupt DNA’s three-dimensional structure and lead to disease. A baby can inherit one healthy copy of TBX5 and still develop serious heart defects if the other copy does not work. That genetic imbalance is [...]New research has revealed the complex biological history preserved in DNA traces on the Shroud of Turin. Fibers taken from the Shroud of Turin nearly five decades ago still contain a complex record of biological material accumulated over centuries. In research published in Scientific Reports, scientists applied advanced genomic sequencing (rigorous PCR-free next-generation metagenomic sequencing) [...]When the history of our ancestry is written, the fact that we've interbred with some of our closest relatives, the Neanderthals and Denisovans, will have a central role. And it will be tempting to write it as a very tidy story: Once we got genomes from these other groups, it was possible to identify the sequences in our genomes that we shared with them.
But in reality, as scientists started poking large enough collections of data, there were regular hints of some strange ancestry in our genomes. It was hard to pin down, though, at least in part because the 2 percent on average of Neanderthal DNA found in many populations does not guarantee that any two individuals will have the same 2 percent. So having the genomes of those two groups made sense of some things researchers had already been seeing.
But knowing what we do about Neanderthal and Denisovan DNA is now allowing researchers to answer a somewhat different question: Is there anything else? Using recently developed analytical techniques, they find evidence of a third lineage that we apparently interbred with before any modern humans left Africa. Again, there were hints of this earlier, but so far, there's been no genome from a modern human relative to help us understand the details—the source of this DNA remains a "ghost lineage."
© BSIP
When the history of our ancestry is written, the fact that we've interbred with some of our closest relatives, the Neanderthals and Denisovans, will have a central role. And it will be tempting to write it as a very tidy story: Once we got genomes from these other groups, it was possible to identify the sequences in our genomes that we shared with them.
But in reality, as scientists started poking large enough collections of data, there were regular hints of some strange ancestry in our genomes. It was hard to pin down, though, at least in part because the 2 percent on average of Neanderthal DNA found in many populations does not guarantee that any two individuals will have the same 2 percent. So having the genomes of those two groups made sense of some things researchers had already been seeing.
But knowing what we do about Neanderthal and Denisovan DNA is now allowing researchers to answer a somewhat different question: Is there anything else? Using recently developed analytical techniques, they find evidence of a third lineage that we apparently interbred with before any modern humans left Africa. Again, there were hints of this earlier, but so far, there has been no genome from a modern human relative to help us understand the details—the source of this DNA remains a "ghost lineage."
© BSIP
A new technique reveals human evolution was rife with interbreeding
The post You’re Carrying “Ghost DNA” From Extinct Hominins appeared first on Nautilus.
In recent years, advances in ancient DNA sequencing have redefined our understanding of human evolution, revealing that our species did not emerge in isolation but repeatedly interbred with close evolutionary relatives like Neanderthals and Denisovans.
Yet one of the field’s greatest mysteries has remained unanswered: What if some of our ancestors also encountered extinct human groups whose DNA has never been recovered from fossils? Now, a recent study published in Science suggests researchers may finally have found a way to detect those long-lost relatives.
Instead of relying on ancient bones or preserved genomes, researchers developed a powerful computational approach capable of identifying genetic traces of previously unknown archaic humans using only the genomes of living people.
Applying the technique to modern populations around the world, the researchers uncovered evidence that an unidentified “ghost” hominin contributed DNA to the ancestors of all living humans before the great migration out of Africa.
Researchers also found new evidence providing evidence for the existence of an even older “super-archaic” human lineage whose genetic legacy may survive today through Denisovan ancestry in Oceania.
“Admixture between modern humans and extinct hominins has shaped the genomes of present-day individuals, but reconstructing this history has been constrained by the scarcity of archaic samples and unadmixed outgroup populations,” researchers write. “We introduce TRACE, a reference- and outgroup-free approach that uses features of ancestral recombination graphs to identify archaic ancestry.”
Past research has sequenced only a handful of high-quality archaic human genomes, all from Eurasia. While those genomes have revealed that most people outside Africa carry roughly 1 to 2 percent Neanderthal DNA and that many Asian and Oceanian populations also inherited Denisovan ancestry, scientists have long suspected those known groups represented only part of humanity’s evolutionary history.
Previous genetic studies had hinted that modern humans, especially African populations, contained fragments of DNA from unidentified archaic relatives. However, because no fossil genomes exist for those populations, proving their existence has been extraordinarily difficult.
The new method, called TRACE, short for “TRacking Archaic Contributions via ARG Estimation,” takes a fundamentally different approach. Rather than comparing modern DNA against known Neanderthal or Denisovan genomes, it reconstructs ancestral recombination graphs. These enormous evolutionary family trees trace how pieces of DNA have been inherited over hundreds of thousands of years.
These ancestral graphs preserve signatures left behind when deeply divergent human lineages interbred. Such events create unusually long branches and distinctive genetic patterns that can persist in descendants for hundreds of thousands of years. By searching for those signatures, TRACE can identify archaic ancestry even when no reference genome exists.
To test the system, the researchers first ran extensive computer simulations modeling ancient human populations and known episodes of Neanderthal interbreeding. The method consistently revealed high accuracy while producing very low false-positive rates.
The team then applied TRACE to genomes from the 1000 Genomes Project, encompassing hundreds of individuals representing populations across Africa, Europe, Asia, and elsewhere.
The program successfully recovered well-established Neanderthal ancestry in Europeans and Asians, along with Denisovan ancestry concentrated primarily in Asian populations. More intriguing, however, was the discovery of an additional category of DNA that matched neither Neanderthals nor Denisovans.
TRACE identified between roughly 0.5 and 1.1 percent “ghost” ancestry across all modern populations examined. The genetic evidence suggests these segments originated from an unknown archaic human lineage that diverged from our ancestors roughly 830,000 years ago, before later contributing DNA to the ancestors of modern humans.
Perhaps most surprising was where that ancestry appeared.
Rather than being confined to African populations, as several earlier hypotheses proposed, the researchers found remarkably similar ghost ancestry in both Africans and non-Africans.
Most of the segments detected outside Africa were shared with African populations, suggesting the interbreeding event occurred before modern humans started dispersing across the globe roughly 50,000 to 70,000 years ago.
The findings point toward a previously unrecognized chapter of human evolution in which an unidentified human population mixed with the common ancestors of everyone alive today.
The researchers also explored where these ancient genetic fragments survive in the modern genome.
They found ghost ancestry spread across more than 70 percent of the accessible human genome, although it was far from evenly distributed. Some regions contained unusually high concentrations of ghost DNA, including genes involved in immune function and metabolism.
Even more unexpectedly, ghost ancestry persisted inside genomic regions previously believed to be largely devoid of archaic DNA.
These regions, known as “Neanderthal and Denisovan ancestry deserts,” have often been interpreted as places where natural selection eliminated archaic genetic variants because uniquely modern human versions proved advantageous.
The presence of ghost ancestry inside many of those same regions suggests the story may be more complicated. Rather than rejecting all archaic DNA equally, natural selection may have acted differently depending on which ancient human lineage contributed the genes.
The study also ventured even farther back in evolutionary time.
Focusing on genomes from Papua New Guinea, Vanuatu, and the Santa Cruz Islands, the researchers searched for evidence of “super-archaic” ancestry—genetic contributions from a lineage that diverged long before Neanderthals, Denisovans, and modern humans separated.
Previous studies had suggested Denisovans themselves may have inherited DNA from such an ancient population. TRACE now provides additional support for that hypothesis.
The team identified deeply divergent genetic segments embedded explicitly within Denisovan-derived DNA in Oceanian populations. Based on their analyses, those ancient lineages may have split from the ancestors of modern humans approximately 1.77 million years ago.
While the researchers stress this represents a conservative estimate of surviving super-archaic ancestry, the findings strengthen the idea that modern humans indirectly inherited DNA from a much older human lineage through Denisovan interbreeding.
The identity of both the ghost lineage and the super-archaic population remains unknown.
The ghost population may represent Middle Pleistocene human groups or African populations of Homo heidelbergensis that encountered the ancestors of modern humans before the Out-of-Africa migration. For the older super-archaic lineage, the researchers note that Homo erectus remains one plausible candidate given its estimated divergence time and broad geographic distribution.
Although the new method cannot yet identify specific fossil species, it provides researchers with an entirely new tool for investigating chapters of human evolution that may never yield recoverable ancient DNA.
Because DNA older than roughly one million years is extraordinarily unlikely to survive outside permanently frozen environments, computational approaches like TRACE are becoming increasingly important for reconstructing humanity’s deepest evolutionary history.
“We find evidence for at least one ghost introgression predating the OOA expansion that contributed ancestry to all present-day populations,” researchers write. “These results point to multiple layers of introgression—both direct and mediated through other archaic groups—shaping modern human genomes.”
The study, “Recovering signatures of archaic hominin introgression using ancestral recombination graphs,” was published in the journal Science.
Tim McMillan is a retired law enforcement executive, investigative reporter and co-founder of The Debrief. His writing typically focuses on defense, national security, the Intelligence Community and topics related to psychology. You can follow Tim on Twitter: @LtTimMcMillan. Tim can be reached by email: tim@thedebrief.org or through encrypted email: LtTimMcMillan@protonmail.com
Science word of the day: Allele
Pronunciation: Ah-LEEL'
What it means: Genes contain the instructions for the various proteins that determine traits, such as eye color or blood type. An allele is a specific variant of a gene. Alleles come in pairs, one from each parent. Some are dominant, meaning that copy will override any instruction from the other allele in the pair, and some are recessive, meaning there have to be two copies of that particular allele for those instructions to translate into an observable feature. Of course, not all inheritance is as simple as dominant and recessive patterns, particularly for traits that arise from combinations of hundreds of genes.
How to use it in a sentence: We learned in grade school that alleles for brown eyes are dominant over alleles for blue eyes, leaving the kids with hazel eyes feeling lost and confused.
Can you crack our science word of the day puzzle, Chain Word?
Hidden genetic diversity may have given it an advantage
The post How an Inbred Snake Invader Took Over an Island Paradise appeared first on Nautilus.
A 6-year-old girl was given a first-of-its-kind gene therapy in a hospital in China for a nonlethal condition. Within a week, she was dead.
Her death was never publicly disclosed by the scientists who developed and administered her experimental gene therapy. But now, more than a year after her death, her parents are telling her story in the hope that others will be spared the same fate.
A new joint investigation from Science and Retraction Watch, published July 23, details the case of "Mei," a young girl given gene therapy in March 2025 at Xinhua Hospital, which is affiliated with the Shanghai Jiao Tong University School of Medicine. (Mei's parents asked that the family's names be changed for the report. Her name was changed to Mei, which is Chinese for "beautiful," and they are referred to as "Jason" and "Linda.")
Mei's trial was led by Zilong Qiu, a neuroscientist at the university's brain center. Live Science has contacted Qiu for comment.
Mei had a rare genetic disorder called Snijders Blok-Campeau syndrome, which is caused by mutations in the gene CHD3. The gene carries instructions for a protein that helps control how DNA is packaged in cells, which in turn, affects how genes can be switched on and off. The gene plays an important role in early brain development. In people with the syndrome, this process is disrupted, leading to brain changes that can cause speech problems and intellectual disability.
Mei's parents had sought further tests after their daughter was diagnosed with global developmental delay in 2023; this broad diagnosis is given to young children who show delays in several areas, such as speech and motor skills. Genetic sequencing following her diagnosis revealed she had the syndrome.
People with the condition typically have normal life expectancy, although symptoms can range in severity, with severe cases coming with seizures and heart problems. Mei's case was mild, and her parents secured her speech and occupational therapy alongside special education support to help manage her symptoms.
Jason worried about her future, though, anticipating that she'd continue to trail behind in school and may never live independently. On WeChat (the instant messaging, social media and mobile payment app), Jason and Linda joined a group of parents of kids with autism and similar disorders. There, they learned about Qiu, the neuroscientist, who has a gene-therapy company called Lanqi Xintu Gene Technology. Qiu had been developing a gene therapy for Rett syndrome, another genetic disorder that disrupts brain development.
Jason contacted Qiu about possibly creating a gene therapy for Mei, and Qiu immediately arranged a meeting. He explained that such a therapy would require delivering viruses into Mei's spinal fluid; modified viruses are often used as vehicles to deliver gene therapies into the body. The viruses would then travel to her brain, where they'd make the desired edits. To get a big enough dose into the brain, hundreds of trillions of viruses would be needed.
Qiu planned to use a base editor, a CRISPR-based approach that swaps out just one letter in DNA's code for another. (The technique was famously used in the case of a U.S.-based baby, called KJ, whose life-threatening genetic disease was successfully treated.)
Because Mei's condition was not life-threatening, the approach would need to clear a high bar to pass the university's ethics board, Qi said. It would need to be trialed in mouse and monkey experiments first. Qiu insisted, though, that the university could ensure Mei's safety, although it couldn't guarantee the treatment would work. The possibility of death wasn't discussed — and it would not be in the years to come.
Jason and Linda agreed to the plan. They would ultimately put the equivalent of $860,000 toward the cost of developing, testing and deploying the therapy; those costs included informal payments made directly to various members of the research team. Charging for an unproven therapy is forbidden under Chinese law, but Qiu explained this away by saying the parents were paying into his gene-therapy company, which then paid for the procedure.
In January 2025, Qiu submitted a manuscript describing the team's lab-animal experiments to the journal Nature. (A revised version of the manuscript was published in February 2026 and contains no mention of the family nor its financial contributions.) Science had several experts review the manuscript, who expressed concerns about how well the monkey study was conducted.
Live Science contacted Nature for comment, and a spokesperson said "We are looking into the matter carefully following an established process. We are unable to provide further information at this time."
The next month, a toxicology study conducted by the team found that four monkeys given the treatment developed moderate to severe liver damage, and one also had kidney damage. This should have prompted additional safety studies, experts told Science, and hinted that the therapy was triggering a dangerous inflammatory response — a known risk of virus-based gene therapies.
The hospital's ethics committee did not review this data before giving the OK for Mei's procedure. Her parents were told about the results of the animal studies, but they said the scientists seemed unconcerned about them. Under China's regulatory system, the trial did not need to be cleared by the country's equivalent of the Food and Drug Administration before proceeding.
On March 24, 2025, after giving her a steroid to dampen potential immune reactions, Dr. Yongguo Yu injected gene therapy-laden viruses into Mei's spinal fluid. Although some virus-based gene therapies in the U.S. can be given with steroids, as of late, doctors often opt for more aggressive immune-suppressing drugs for safety.
Within days, Mei developed a range of symptoms; she got a fever, wasn't urinating, and her platelet levels plummeted. She was taken into an intensive care unit for treatment, but she died seven days after receiving the injection.
The hospital determined her death was directly related to the treatment and caused by thrombotic microangiopathy. This is an immune reaction that causes blood clots and can arise from virus-based gene therapies.
The hospital was later fined the equivalent of about $3,600 for failing to properly oversee the trial and not registering it as commercially sponsored research in China's national database. The hospital required that the doctor involved receive verbal counseling.
The family asked Qiu to withdraw his Nature paper, worried that other families might be tempted to try the same therapy, and he initially agreed, although it was later published. The paper was covered positively in the press at the time, and parents in the WeChat group began expressing interest. Seeing that, Jason and Linda submitted a complaint to Shanghai Jiao Tong University School of Medicine, calling for a retraction and investigation. The university took no action.
They also sent a letter to Nature after the publication; at the time, the journal said that the ethical issues raised "fall outside our purview in terms of data integrity" and that the matter should be handled by the university.
Regarding the investigation, neither Qiu, Lu, the university or the hospital responded to Science's requests for comment. Nature told Science that it was not aware of the issues surrounding the clinical trial before it published the group's paper.
You can read the full investigation by Brendan Borrell at Science, along with a breakdown of the top four takeaways from the case. In particular, Mei's death raises questions about China's regulations around experimental therapies and human clinical trials, especially in the wake of the infamous "CRISPR baby" cases that purportedly prompted the country to tighten its restrictions around gene editing.
Editor's note: This story was updated at 3:00 p.m. on July 24, 2026, with new comments from Nature. It was first published at 2:00 p.m. the same day.
Researchers have discovered that children's brains can contain cells with their mother's DNA and that these cells can persist for decades.
The findings, which were posted to the preprint database bioRxiv June 10 but have not been peer-reviewed yet, are part of a growing body of work showing that a mother and fetus exchange cells during pregnancy — a phenomenon known as "microchimerism." Previously, scientists had found that a mother's brain harbors cells with her children's DNA.
The findings are important for several reasons, said Amy Boddy, co-director of the Microchimerism, Human Health and Evolution Project at the University of California, Santa Barbara, who was not involved in the study. Past work mostly found evidence of maternal microchimerism in infancy, and in blood samples, she told Live Science in an email. "What's exciting here is that it's tissue, not blood; it's real human data, not an animal model; and the methods are cutting-edge."
More broadly, the work reinforces the idea that microchimerism is "a normal process of mammalian biology," Boddy said.
Before this study, there was sparse evidence for maternal microchimeric cells in brains, mostly because it is hard for researchers to get samples of human brain tissue and DNA from both parents and their children.
To overcome this challenge, a team led by Sami Kanaan, a staff scientist at the Fred Hutchinson Cancer Center in Seattle, analyzed brain tissue that had been surgically removed from dozens of children with severe epilepsy as part of their treatment. The patients ranged in age from 28 days to 19 years at the time of their surgery, and their mothers provided DNA samples through cheek swabs.
Kanaan's team used a tool called quantitative PCR to identify and count maternal cells hiding among millions of cells in the children's brains.
Out of 37 mother-child pairs, 26 children — 70% — had their mother's cells in their brains. These maternal cells were distributed across multiple regions of the brain, including the frontal, temporal and parietal lobes, which sit on the brain's outer surface, and the hippocampus, which is buried deep inside. Each sample had, on average, about 2.2 maternal cells per 100,000, though one sample from the hippocampus had 459 maternal cells per 100,000 and 11 children had no evidence of maternal DNA in their brains.
That prevalence is probably underestimated, Boddy said, "due to the limits of detecting rare cells at low frequency with this method."
Being a firstborn child seemed to increase the odds of having maternal cells in the brain. Of the children who carried their mother's cells, 14 were firstborns and 12 were later-born. In contrast, among the children who didn't have these cells, only one was a firstborn and 10 were later-born.
Using a technique called single nucleus RNA sequencing, which reveals what a cell is doing by showing which genes within the cells are switched on, the researchers found that the maternal cells had transformed into several types of brain cells. Likely, these cells were originally leukocytes and stem cells and had been transferred to the fetus via the placenta or during pregnancy or breastfeeding.
The transformed cells included neurons; oligodendrocytes, which produce the protective sheath around neurons; astrocytes, which support many brain functions and help fuel neurons; microglia, the brain's immune cells; and endothelial cells, which line blood vessels.
"Being able to use single-nucleus RNA sequencing to identify what type of cells the maternal microchimeric cells actually are is amazing," Boddy said. "We've been so limited in understanding the function of these cells, and papers like this, with these methods, are getting us closer."
To see whether these findings also applied to people without epilepsy, the researchers examined brain autopsy data from 29 individuals with no known neurodevelopmental conditions, ranging in age from 22 weeks of gestation to 40 years. They also analyzed brain tissue from three men in their late 80s and early 90s without any known brain conditions originally collected as part of an Alzheimer's disease study.
In total, the researchers found foreign cells in 25 of 32 people — about 78% — including in the brain of a man in his 90s.
The researchers suspect these foreign cells are maternal, but they couldn't confirm it because they didn't have DNA from the mothers. It is possible that the foreign cells came from a twin; an older sibling; a past pregnancy, miscarriage or abortion (in females); or, rarely, from a maternal grandmother, the team wrote in their paper.
As in the epilepsy patients, these cells had matured into several types of working brain cells. In younger brains, they most often became a specific kind of neuron, a layer 2/3 neuron, while in older brains, maternal cells were more likely to be microglia.
Given that these microchimeric cells take on very different roles, it would be interesting to know whether that diversity reflects their origins — for example, whether they came from a mother, an older biological sibling or a maternal grandmother, said Dr. Sing Sing Way, a microchimerism researcher at Cincinnati Children's Hospital Medical Center who was not involved in the study.
The number of maternal cells declined with age, but they never completely disappeared.
Boddy said the findings mostly raise new questions. "Do we maybe need microchimeric cells to 'help out'?" she asked. "Is diversity of cells in the brain important, or is it just a byproduct of being a placental mammal?”
Because microchimeric cells appear to be common, Boddy suspects they "are doing an important job in the brain, so understanding their function could be very important for understanding healthy brain development."
By using new analytical tools to pinpoint microchimeric cells, the study "pushes the boundaries" of previous research, but future studies would benefit from larger and more uniform datasets, Way said. That would mean obtaining more brain biopsies, analyzing more cells from each sample, collecting specimens at different ages, and sampling similar brain regions across individuals to better compare the results.
This article is for informational purposes only and is not meant to offer medical advice.
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