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27 February 2026 |
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Today’s Deep Dive delves into a new way of ensuring brain surgeons only remove what they must. But first, catch up on the latest science news, including birds’ sweet genes and how to help T cells break into tough tumors. |
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Anthropology | News from Science |
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My dad the Neanderthal |
Scientists have known for more than 15 years that our species, Homo sapiens, interbred and created offspring with our close evolutionary cousins, the Neanderthals, at several points in the distant past; some 2% of the DNA in living non-African populations comes from these ancient pairings. But one of the more curious associated discoveries was that none of the Neanderthal DNA in modern humans is mitochondrial DNA, which is passed down from mothers to their children. Because of that, researchers supposed that most of the successful interspecies breeding occurred between Neanderthal males and H. sapiens females, which got scientists wondering: Was there a fatal, genetic incompatibility that afflicted the offspring of H. sapiens
males and Neanderthal females? Or, did Neanderthal males preferentially mate with modern human females (or vice versa)?
To investigate, researchers examined the ancient DNA from three Neanderthals, looking for traces of H. sapiens DNA that had been introduced into their lineage. Specifically, they looked at regions in the genome that, in modern humans, are known as “Neanderthal deserts”—genetic stretches along the X chromosome that lack Neanderthal DNA. If Neanderthal X chromosomes likewise had similar “H. sapiens deserts,” it would suggest that some genetic incompatibility thwarted offspring between Neanderthal females and H. sapiens males. But that isn’t what they found. In fact,
they found more modern human DNA on the Neanderthal X chromosomes.
The most likely scenario explaining this pattern, the researchers argue, is that Neanderthal males mated more often with H. sapiens females, depleting the human gene pool of Neanderthal X chromosomes and boosting H. sapiens X chromosomes in the Neanderthal gene pool.
However, nobody can say why this preference existed—or whether the attraction was mutual. Either way, mating preferences have been underappreciated as a factor in the mixing of the two species. “Sex bias is something that’s really pervasive” across humanity’s past, noted population geneticist Sohini Ramachandran. |
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Read the Science paper |
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Animals | Science |
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Sweet relief |
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Many hummingbirds, like this Anna’s hummingbird, can withstand blood sugar spikes more than twice as high as humans can. Becky Matsubara via Flickr |
CC BY |
As tasty as desserts and soda may be, doctors advise we lay off the sweets to avoid developing conditions like obesity and type 2 diabetes. Many birds, on the other hand, have adapted to thrive on sugary diets.
To study what enables birds to suck up such sweet treats, researchers compared the genomes of five bird species that eat nectar and fruit with four species that prefer seeds, insects, or meat. They discovered thousands of similar genetic changes in areas controlling blood pressure, insulin, and metabolism among the sugar-eating birds, they reported this week in Science
. And every sugar-eating species displayed a change in a gene that helps the birds convert excess glucose into fat storage. When implanted into human cells, the gene helped the cells metabolize carbohydrates.
Plenty of birds seemed to have figured out these sweet tricks, including parrots, honeyeaters, and hummingbirds, which regularly withstand blood sugar spikes more than twice as high as humans’. That’s likely because most of the genetic changes deal with controlling other genes, rather than coding for specific proteins—a strategy that helps birds respond to sugar in many ways at once.
“This is a stunning example of evolutionary integration,” physiologist Chang Zhang told Science News. “It suggests that evolving to thrive on a diet of nectar and fruit isn’t just about processing the sugar itself.” |
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Cancer | Science |
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Targeting the almost-negative: Getting CAR T to tackle solid tumors |
Since their first clinical successes more than a decade ago, CAR T therapies have transformed treatment for certain blood cancers. By engineering a patient’s T lymphocytes, a type of white blood cell, to recognize a specific protein on malignant cells, doctors can produce durable remissions in leukemias and lymphomas that were once difficult to treat. But solid tumors are trickier to tackle.
“There are tumors that impede the entry of T cells,” Michel Sadelain, cancer immunologist, told Fierce Biotech. “Some are very smart. There’s many, many layers of defense that they can put up against the immune system.”
Even when T cells do infiltrate, another problem emerges. In many blood cancers, nearly all tumor cells display the same target protein at high levels. Solid tumors are more heterogeneous, with some cells expressing a potential target in abundance, while others do so but faintly; some cells are even labeled “negative.”
In a study published in Science, researchers targeted CD70, a protein that is overproduced in solid tumor cancers, such as kidney, ovarian, and pancreatic cancers. Using high-sensitivity protein and gene expression analyses, they found that even tumor cells labeled CD70-negative still expressed very low levels of the protein
. Conventional CAR T cells are not sensitive enough to detect those faint signals. So, the team engineered a more responsive receptor, called an HLA-independent T cell (HIT) receptor, designed to recognize even minimal CD70 expression.
In preclinical models, including patient-derived tumor grafts and mouse studies, these ultrasensitive CD70-HIT cells completely and durably eliminated tumors with mixed levels of CD70 expression. If successful in clinical trials, this immunotherapy could be used in the treatment of over 20 types of solid tumor cancers.
“There are multiple obstacles to the efficacy of these cells in solid tumors, and I think that’s why people are optimistic,” said Sadelain. “Once you start understanding the problem, you’re going to find solutions to overcome it.” |
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Mass timber is poised to reshape construction |
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A new wood product called mass timber could help meet the demand for environmentally conscious building materials. The University of Arkansas Fay Jones School of Architecture and Design is educating the next generation in mass-timber innovation. |
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Deep Dive |
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Taylor Furst, M.D., observes a brain mapping procedure in progress at the University of Rochester’s Strong Memorial Hospital. Matt Wittmeyer |
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Brain mapping gets a wakeup call |
In 2020, a British woman named Dagmar Turner gave an unforgettable performance on the violin. While her musical talent would have been impressive on its own, what was truly remarkable was that the concert—which included music by Gustav Mahler, George Gershwin, and Julio Iglesias—took place in the middle of an operating room while surgeons removed a tumor from the right frontal lobe of Turner’s brain.
When removing cancerous tissue, neurosurgeons must strike a careful balance between excising as much of the tumor as possible while avoiding damage to critical brain areas. To do so, they often wake the patient up mid-surgery and stimulate parts of the brain surface to assess neurocognitive functions in real time. In Turner’s case, doctors focused on sparing regions that control delicate hand movement and coordination, ensuring that her ability to play the violin wouldn’t be compromised.
While the basic features of “awake brain mapping” have remained mostly unchanged for decades, scientists are also looking for ways to make the method even more effective. Before surgeons operated on Turner, for example, they first used an imaging technique called functional MRI to create a detailed map of her brain activity. Now, the authors of a new Science Advances study may have found a way to
push the limits of awake brain mapping further than ever before.
Traditionally, surgeons who use this technique have relied on binary outcomes, using gentle electrical impulses to stimulate a specific area of the brain and checking to see whether the patient can successfully complete a task. If doctors want to determine where language is located, for instance, they might have the patient name pictures or read words. If the patient can respond quickly and correctly while part of their brain is being stimulated, then that area can probably be safely removed. “
It’s either, yes, this region is involved, or no, this region is not involved, and that’s the way it’s been done for over 50 years,” lead study author Raouf Belkhir tells Science
podcast host Sarah Crespi. “But sometimes even with this method, which is the clinical gold standard, patients will still wake up with language difficulties.”
In reality, Belkhir explains, effects are rarely so black-and-white. Instead of causing an obvious error, for example, stimulating an area of the brain might subtly delay a patient’s response. When it comes to mapping language, the timing of the electrical impulse also matters, since different areas of the brain are responsible for different steps in the speaking process. “ We find that early stimulation slows finding the right word and later stimulation delays actually saying the right word,” says Belkhir. If the surgeon stimulates too late, after “the train’s already left the station,” they might miss crucial information.
“This research shows that by measuring aspects of patient performance that were previously not considered relevant for awake brain mapping, even better predictive models of brain organization can be developed,” study corresponding author Bradford Mahon explains in a statement.
Hoping to translate these findings into clinical practice, the researchers developed a software platform called MindTrace, which uses neurocognitive assessments conducted before, during, and after surgery to help doctors predict how a particular approach will affect functions like speech and movement. “This technology will allow us to see, in real time, how different surgical decisions may impact a patient’s future brain function
,” study co-author Tyler Schmidt explains in a statement. |
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Listen to the Science Podcast |
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Stem cells safe for spina bifida in utero |
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Six children who received a stem cell patch in addition to surgery to treat spina bifida while they were still in utero show no signs of harm from the novel therapy. “We didn’t see any significant adverse effects in any way,” said one of the researchers behind the trial. “And the treatment … didn’t interfere with the expected fetal surgery-only benefits.” |
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The Lancet Paper | Read more at
News from Science |
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Tiptoeing T. rex |
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An analysis of tracks suggests Tyrannosaurus rex walked on its tiptoes, much like birds do today. “This study shows that even the iconic T. rex was quite birdlike in the way that it walked,” explained one paleontologist. “It would have been something like an 8-ton chicken clucking about in the barnyard.” |
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Royal Society Open Science Paper | Read more at
The New York Times |
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Probably, probably not |
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If ChatGPT tells you something is probably going to happen, it might not be as likely as you think it is. AIs and humans don’t align well when it comes to terms that assess probability, according to a new paper. “This could be because humans can interpret words such as ‘likely’ and ‘probable’ based more on contextual cues and personal experiences,” explained one of the study’s authors. “In contrast, large language models may be averaging over conflicting usages of those words in their training data, leading to divergences with human interpretations.” |
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NPJ Complexity Paper | Read more at
The Conversation |
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