Tens of thousands of years ago, Neanderthals mated with modern humans and passed along a gene variant that enables us to pack on more muscle, a new study finds.
Researchers found that this specific Neanderthal gene, a variant of the growth hormone receptor gene, causes cells to respond strongly to growth hormone. The Neanderthal version of the gene creates a growth hormone receptor with two amino acid changes and one deletion, compared with the typical receptor in most modern humans. The researchers think it entered the modern human gene pool through interbreeding, probably about 47,000 years ago.
"The most noticeable characteristic would likely be greater muscle mass, around 270 grams [9.5 ounces] per copy of the variant," study co-author Hugo Zeberg, a geneticist at the Karolinska Institute in Sweden, told Live Science in an email. "A person who inherited two copies, one from each parent, could therefore have more than half a kilogram [1.2 pounds] of additional muscle mass."
The study, published Aug. 5 in the journal Cell, found that almost all Neanderthals had this gene variant, but only about 10% of modern humans do. Certain modern human groups were more likely to have it, with the variant showing up in about 1% of modern people with European ancestry, and up to 25% of those with Southern Asian or Southeast Asian ancestry. It does not seem to appear in people of African ancestry, possibly because the interbreeding happened in Eurasia.
Human growth hormone is produced naturally by most people in the brain's pituitary gland, and it stimulates growth in children and adolescents. Some people have too much or too little human growth hormone, but most of these cases can be medically treated for it. The pituitary gland is also essential in adults for producing hormones that have several roles, including regulating metabolism, stimulating ovulation in ovaries, and stimulating testosterone production in testicles.
In the study, the researchers studied 10 samples of Neanderthal DNA and two samples of Denisovan DNA from archaeological sites in Europe, the Balkans, Siberia and Asia. (The Denisovans were closely related to the Neanderthals.)
They compared their results to modern biobanks that store more than 1.1 million human genomes and related physical data, to understand the effects of the gene variant.
The researchers next tweaked cells in the laboratory to express the regular and Neanderthal variants of the gene, and found that the Neanderthal cells multiplied about 40% more often than regular cells when flushed with growth hormone. Despite this, the Neanderthal gene variant doesn't always make people look bulkier, the researchers found. Instead, the differences are more subtle: for example, people who have this gene variant would have higher levels of a key signaling protein in response to growth hormone, the researchers wrote.
The team also found that people with the gene variant might have slightly shorter tooth roots and small differences in their jaw shape — features that are seen in Neanderthals, who went extinct around 40,000 years ago.
Neanderthals were, in general, stockier than modern humans. But Zeberg thinks their enhanced response to growth hormone does not fully explain why Neanderthals were generally more robust and "thick-set" than modern humans.
"It cannot explain the Neanderthal body type on its own," he said. "Neanderthal robustness was almost certainly shaped by many genes, as well as by development, lifestyle, and environmental factors. Our results provide one possible piece of a much larger puzzle."
The placenta produces a particular form of growth hormone for a fetus, which differs from the form of growth hormone produced by the pituitary gland. However, it seems the Neanderthal variant doesn't respond to growth hormone from the placenta. As a result, Neanderthal babies were the same size at birth as modern human babies but grew faster after that, Zeberg said.
In the study's sample of modern humans, the team noticed that children aged 11 or younger with the gene variant didn't show the effect; rather, only older individuals did. This suggests that the gene variant's differences might not emerge until puberty, strengthening the idea that it responds only to growth hormone produced by the pituitary gland and not by the placenta, the researchers said.
"Growth hormone is also particularly important during puberty, when its levels rise substantially," Zeberg said. "The effect of the variant is therefore likely to be especially important during puberty and later development, rather than before birth."
Kornelius Kupczik, a paleoanthropologist at the University of Chile in Santiago who was not involved in the study, told Live Science that it was notable to see such a high prevalence of the Neanderthal gene variant in people of South Asian and Southeast Asian ancestry, when it was relatively rare among Europeans.
This suggests that early human migrations may have been more complicated than had been assumed — a "curious" challenge that required further investigation. "I guess that's something we still have to find out," he said.
How much do you know about our closest relatives? Find out with our Neanderthal quiz!
Around 11,000 years ago, communities in southwest Asia began one of the most consequential experiments in human history: growing their own food. Wild cereals, legumes and fruit-bearing plants were gradually brought under human management, setting in motion the transition from mobile hunter-gatherer lifeways to farming societies. For decades, archaeologists have assumed that one of the earliest signs of this transformation was an increase in cereal grain size. A new study, however, suggests that some of the biggest grains found at the dawn of agriculture may not have been genetically altered at all. They may simply have grown in wetter conditions.
The findings, published in the Proceedings of the National Academy of Sciences, challenge a central assumption about how cereal domestication began. Researchers studying charred barley and emmer wheat grains from the Early Neolithic sites of el-Hemmeh and Sharara in the southern Levant found that the plants still possessed fully wild characteristics during the earliest phases of the Pre-Pottery Neolithic. Their ears had brittle rachises, the structures that naturally break apart when mature, allowing seeds to disperse in the wild. There was no evidence of the tough, non-shattering rachis that later became one of the defining features of domesticated cereals.
The absence of non-shattering forms is significant because a tough rachis makes harvesting far more efficient. In wild cereals, the rachis fractures as the plant ripens, scattering seeds before people can collect them. A mutation that keeps the grains attached would have offered major advantages to human harvesters and could then have spread through repeated cultivation and replanting. Researchers have therefore often treated the appearance of non-shattering cereals as a key marker of domestication. Grain size, by contrast, has frequently been interpreted as an earlier signal that people were already selecting plants through cultivation.
At el-Hemmeh and Sharara, however, grain size told a more complicated story. Barley and emmer wheat remained morphologically wild, yet their grains varied dramatically. Some were as small as typical wild cereals, while others fell within the size range commonly associated with domesticated plants. If large grains were the product of genetic selection caused by systematic tillage, the researchers expected to find other evidence of intensive cultivation. Instead, the ecological evidence pointed toward relatively low-disturbance environments.
The team examined the weed species preserved alongside the cereal remains. Weeds are valuable archaeological indicators because different plants thrive under different environmental conditions. Species associated with heavily tilled or frequently disturbed soils were not dominant in the assemblages from these early sites. This weakened the argument that repeated ploughing or intensive soil preparation had already created strong selection for larger seeds. The researchers began looking for another explanation for the striking variation in grain size.
Their answer came from stable carbon isotope analysis. Carbon exists in several naturally occurring forms, or isotopes, and plants incorporate these isotopes in ways that are influenced by their growing conditions. In cereals, the stable carbon isotopic composition of a grain can reflect the balance between carbon uptake and water loss during photosynthesis. When plants experience water stress, changes in gas exchange through their leaves alter the carbon isotope signal recorded in their tissues. By measuring this signal in ancient grains, scientists can reconstruct aspects of the moisture conditions under which the plants grew.
The results showed a strong relationship between grain size and water availability. Barley grains that reached domestic-sized dimensions had carbon isotope values indicating that they developed under wetter conditions. Smaller, wild-sized grains carried signatures consistent with considerably drier growth environments. The difference suggests that environmental moisture, rather than inherited genetic change, was responsible for much of the early increase in cereal grain size. In other words, the same wild plant population could produce grains of very different sizes depending on the conditions it experienced during development.
This phenomenon is known as developmental plasticity: the ability of a single genotype to produce different physical traits in response to the environment. It is widespread in plants and can affect characteristics such as height, leaf area, flowering time and seed production. In the Early Holocene southern Levant, developmental plasticity may have created the visual impression that cereals were already becoming domesticated. People collecting and replanting the largest grains might eventually have generated genetic selection, but the initial size increase itself appears to have been ecological rather than evolutionary.
“Environmental conditions provided a much better explanation for the observed variation in grain size than genetic selection under tillage,” said Dr Jade Whitlam of the University of Oxford, who led the study. The researchers propose that genetic selection for larger grains may have occurred later than previously thought, perhaps after selection for non-shattering rachises had already begun. This reverses the sequence often assumed in models of domestication and places greater emphasis on the complex interaction between climate, plant biology and human harvesting practices.
The study also reframes the origins of agriculture as a gradual process of niche construction rather than a sudden decision to domesticate plants. Early communities altered their relationship with wild vegetation through harvesting, protection, transport and repeated use of particular landscapes. These practices may have changed plant populations long before crops displayed unmistakable domestication traits. By combining archaeobotany, weed ecology and stable isotope evidence, the researchers argue that the first steps toward agriculture were not necessarily driven by deliberate genetic engineering of crops, but by prolonged human management operating within a variable environment. The result is a more nuanced picture of farming’s origins—one in which climate could temporarily make wild cereals look domesticated before their genomes caught up.
Subject of Research: The environmental and biological processes that influenced cereal grain size and plant domestication in the Early Holocene southern Levant.
Article Title: Developmental plasticity under human management shaped cereal evolution prior to domestication in the Early Holocene southern Levant
News Publication Date: 4-Aug-2026
Web References: https://www.eurekalert.org/multimedia/1146086
References: Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.2535274123
Image Credits: Jerome Poulalier, www.jerome-poulalier-photography.com
Keywords: Archaeology, archaeobotany, cereal domestication, agriculture, Neolithic, Early Holocene, southern Levant, barley, emmer wheat, stable carbon isotopes, developmental plasticity, plant evolution, climate, hunter-gatherers
Italian archaeologists have discovered a previously unidentified, nearly 4,000-year-old “Tomb of the Giants,” or “Giant’s Tomb,” at Carrarzu Iddia in central-western Sardinia.
The researchers behind the historic discovery said the new structure is part of a larger group of ancient, ‘enigmatic’ burial complexes on the island known as Giant’s Tombs erected by the Nuragic civilization as collective burial sites beginning around 1800 B.C. due to their megalithic structure.
According to Finestre sull’Arte, the newly discovered Giant’s Tomb had been covered by thick vegetation, helping it to remain hidden for nearly four millennia. However, surveyors from Sardinia’s two Superintendencies of Archaeology, Fine Arts, and Landscape were already involved in the restoration and excavation of the nuraghe located at the same site when they made the unexpected discovery.
Located at an elevation of approximately 800 yards, the newly identified Giant’s Tomb is located on the southern slope of Crastu Littu. The Italian team suspects the site “is of particular interest” due to its strategic location.
For example, the Giant’s Tomb offers a sweeping view of the Macomer plain. The location also includes a clear vantage point to observe the highlands of Abbasanta and Paulilatino, and an unobstructed view as far as the hills of the Nuoro area and the Gulf of Oristano. The team said this view likely conveys the site’s importance within the wider settlement network of Nuragic Sardinia.
After identifying and surveying the new Giant’s Tomb’s location, the two project leaders worked with the landowners to clear away the dense overgrowth and earthen debris that had kept it hidden. Ironically, once the site was fully revealed, the team noted that the covering had likely helped to maintain and preserve its excellent condition over the nearly 4,000 years since its construction.
The most prominent features identified on the vast site were two large stone platforms, called protonuraghi, a sacred well, a residential settlement, and an extensive burial ground. A closer examination confirmed that the Giant’s Tomb, which is made from trachyte blocks, retained the expected architectural elements found in similar collective burial sites.
One identifying feature is the site’s exedra preceding its entrance. According to the Italian team, this architectural component is one of the most representative aspects of previously identified Giant’s Tombs, distinguishing this “monumental” construction type clearly within that of protohistoric Sardinia
Unfortunately, the excavation revealed that some portions of the ancient site had not survived the intervening four millennia completely intact. The authorities suspect that past illegal excavations that have affected many ancient sites could be part of the cause.
Luckily, previous illegal invasions of the site did not remove everything of historical value. For example, the team found ceramic materials inside the structure that document human occupation of the site, in some cases dating back to the earliest stages of the Nuragic civilization.
Alongside the site’s more familiar features, the team also identified an internal feature they described as ‘rare’ for a Giant’s Tomb: a second level near the entrance. Future studies of this unusual feature may offer insights into this society’s funerary practices and its construction techniques, which the team notes are still poorly understood.
The Italian team also noted the site’s greater significance when within the larger archaeological context of Carrarzu Iddia, noting that the area has yielded traces of human use and occupation covering the times before, during, and after the Roman era.
When discussing the site’s historical significance, the Italian team pointed to the value of so many extraordinary structures and monuments concentrated within one specific area. This overlap allows researchers to chronologically date the new Giant’s Tomb and place its significance within the wider context of the Island’s inhabitants.
Christopher Plain is a Science Fiction and Fantasy novelist and has spent the last six years as Associate News Editor and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him at christopher@thedebrief.org
A University of Warsaw scientist has determined that a series of mysterious stonemason inscriptions on the Tauchira Gate at Ptolemais, on Libya’s northern coast, which have perplexed researchers for centuries, are likely stonemason marks intentionally left visible by the artisans who built the ancient structure.
The new analysis, which was performed by Anna Urszula Kordas of the Faculty of Culture and Arts at the University of Warsaw in Poland, also dates the gate’s construction to the reign of Ptolemy VIII, roughly 2,200 years ago.
If correct, the new dates for the site would help settle a longstanding debate about the gate’s precise age.
According to Korda’s research study, archaeologists consider the Tauchira Gate to be the best-preserved section of the ancient fortifications built around the ancient Egyptian city of Ptolemais. Several visitors and scholars have noted the gate over the centuries, with a particular focus on its mysterious stonemason inscriptions.
The earliest documented attempt by a Western researcher to decipher their meaning comes from a French traveler identified as Granger, who recorded the marks sometime between 1733 and 1734. According to Korda, that first attempt mistakenly described the marks as likely instructions for masons to arrange the gate’s stones during its construction.
A second, 19th-century effort inaccurately ascribed the mysterious stonemason inscriptions to donors financing specific blocks. In the 1970’s, another researcher suggested the inscriptions were ‘ephebic’ names added after construction as graffiti “unrelated to the gate’s construction but connected to the functioning of the nearby gymnasium.”
Although the most recent effort dated the inscriptions to sometime during the city’s Roman period, Korda notes that the date is still in debate. She also points out that the meanings of the mysterious stone inscriptions were unlikely to be any of the proposed explanations, motivating the new analysis.
To decipher the mysterious stone inscriptions, Korda said she reconstructed the gate’s construction process, organization, and chronology by applying the “chaîne opératoire approach.” This method allowed Korda to study these variables “within its technological and socio-cultural context.”
Thanks to a series of photographs captured by the Polish Archaeological Mission to Ptolemais in 2006, Korda was able to trace the location of each inscription using digital mapping software. The researcher notes that this process still included challenges, including “damaged stone surfaces, suboptimal picture quality, invasive plants, and later inscriptions,” all of which made some of the actual stone markings illegible. Korda said these limitations also hampered the “observation of stone processing techniques.”
After a thorough initial examination, Korda separated the mysterious stonemason inscriptions into 27 ‘types’ and then split them into two groups. The first group represented marks found on rough, unfinished blocks. These marks were also mostly hidden from view, suggesting they were recorded during a block’s quarrying and transport.
Korda’s second group included inscriptions found on finished, textured outer surfaces of the gate’s two towers. Notably, the second group of markings appeared to be carved with more care than those in the first group.
Korda ultimately determined that the inscription pattern represented two distinct systems used to organize and pay for stonemason work. For example, some marks appear to follow a simple letter sequence, which Korda suggests shows how the team was divided for work.
“The stonemasons’ marks on the Tauchira Gate consist of single Greek letters, double letters, ligatures, and elaborate monograms,” the study author writes. “The marks A, Β, Γ, Δ, AP/Ε, Ζ, and Η likely form a letter-label system representing the division of labour among stonemasons’ teams.”
The analysis also revealed some of the mysterious stone inscriptions combine to form complex monograms. Korda said these inscriptions “appear as ligatures or monograms, possibly abbreviating stonemasons’ names.” The inscriptions also likely represent names or workshop owners or private donors who helped fund the project, a common Greek practice during this era.
“The hypothesis presented here is that the marks, especially attested in the lower levels, correspond to the division of stonemasons into seven teams numbered A to H and suggest a well-organized system, possibly financed from public funds,” Korda writes.
One unusual aspect highlighted by Korda’s work was that the mysterious stonemason inscriptions were not hidden during construction, unlike stonemason marks found at other ancient construction sites. The researcher suggests that the marks on the Tauchira Gate being left visible were an intentional act representing a local tradition instead of a wider societal practice.
“Even in the absence of instructive parallels—whether due to lost evidence or gaps in research—it may be inferred that the practice of inscribing rusticated blocks with masons’ or patrons’ names, while inspired by the broader Greek tradition of commemorating benefactors on public buildings, represents a local innovation,” Korda writes, adding that the Tauchira Gate is, therefore, “remarkable for its distinctiveness, as fortifications displaying comparable evidence for labour organization and the public display of stonemasons’ marks remain without close parallels.”
Along with successfully deciphering the meaning of the mysterious stone inscriptions, Korda’s analysis determined that the gate’s two towers were built at the same time instead of one after another. Kordas said this finding contradicts a 2009 German team that examined the site in person.
Because the gates lack organic material for radiocarbon testing, Kordas dated their construction by comparing the shapes of the letters used in the inscriptions with other inscriptions from the same region that have been conclusively dated. The researcher also factored in nearby graffiti mentioning a visitor from Rhodes, which helped narrow the site to the earlier half of the second century BC.
“The arguments deployed by the epigraphic analysis of the marks on the Tauchira Gate and the evidence of the stonemasons’ marks visible there and presented in the analysis submitted here suggest that the gate was remodeled during the reign of Ptolemy VIII Physcon in the second century BC,” Korda concludes, adding that “at the very least, the hypothesis merits serious consideration.”
The article “Life on a Hellenistic Construction Site: Stonemasons’ Marks on the Tauchira Gate at Ptolemais in Cyrenaica” was published by Cambridge University Press.
Christopher Plain is a Science Fiction and Fantasy novelist and has spent the last six years as Associate News Editor and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him at christopher@thedebrief.org
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