![\"Neanderthal](\"https:\/\/www.newsbeep.com\/uk\/wp-content\/uploads\/2026\/08\/neanderthal-gene-greater-muscle-1.jpg\")
<\/a>Neanderthal and modern human reconstructions at the Neanderthal Museum, Germany. The study links a Neanderthal gene to greater muscle mass in modern humans. Credit: suchosch via Flickr, CC BY-SA 2.0.<\/a><\/p>\nA new study found the gene affects how cells respond to growth hormone. The gene came from Neanderthals through mating with early modern humans, likely about 47,000 years ago.<\/p>\n
The gene controls a receptor called GHR, which binds to growth hormone. Neanderthal<\/a> GHR has two amino acid changes and a small DNA deletion compared with the usual modern human form.<\/p>\n Researchers studied ancient DNA from 10 Neanderthal samples and two Denisovan<\/a> samples. They compared these results with data from more than 1.1 million modern human genomes.<\/p>\n Almost all Neanderthals carried the gene variant. Among people today, its frequency differs sharply between populations.<\/p>\n The variant is rare among people with European ancestry. In South and East Asia, the gene occurs much more often. Researchers found a frequency of about 24% in a Pakistani population.<\/p>\n The team then tested the two GHR forms in living cells. They exposed the cells to growth hormone made by the pituitary gland.<\/p>\n Cells with the Neanderthal receptor grew about 40% faster after hormone exposure. The receptor also produced stronger activity in the JAK2-STAT5 signaling pathway.<\/p>\n Further tests pointed to one amino acid<\/a> change as the main cause. The change affects signals inside the cell after growth hormone binds to the receptor.<\/p>\n The researchers also looked at body measurements from modern human carriers. Adults with one copy of the Neanderthal gene weighed about 285 grams more.<\/p>\n Almost all of this extra weight came from muscle. Each copy of the gene was linked to about 271 grams of additional muscle mass.<\/p>\n Carriers also showed several small traits linked with Neanderthal anatomy. These included shorter parts of the lower jaw, a higher risk of overbite, and shorter tooth roots.<\/p>\n The effects don\u2019t seem to appear during early childhood. Researchers found no clear differences among carriers up to age 11.<\/p>\n The difference emerged later, around the period when growth hormone levels rise during puberty. This suggests the gene has a stronger effect during puberty and adult growth.<\/p>\n The study also found an important difference before birth. The Neanderthal receptor responded more strongly to pituitary growth hormone, but not to placental growth hormone.<\/p>\n Placental growth hormone supports growth before birth. The finding fits the lack of differences in birth weight among people carrying the Neanderthal gene.<\/p>\n The gene doesn\u2019t explain the full Neanderthal body shape. Neanderthals had many genetic and environmental factors shaping their stocky build.<\/p>\n Other genes also sit close to GHR on the inherited DNA segment. Researchers therefore can\u2019t rule out effects from nearby genetic changes.<\/p>\n Still, the results show how ancient gene flow shaped some traits in modern humans. A gene once common among Neanderthals now affects growth hormone signaling in part of today\u2019s population.<\/p>\n The findings also add to evidence that some features of Neanderthal anatomy survived through interbreeding<\/a>. In this case, the ancient gene is linked with muscle mass, growth, and small differences in the face and teeth.<\/p>\n![\"Neanderthals'](\"https:\/\/www.newsbeep.com\/uk\/wp-content\/uploads\/2026\/08\/neanderthals-advanced-toolmaking-skills-1.jpg\")
<\/a>Neanderthal family, photo taken at the Anthropos Pavilion in Brno, Czech Republic. Credit: Jaroslav A. Pol\u00e1k<\/p>\n