The Secret Behind People Who Build Muscle Easily: Neanderthal DNA Found

Ancient Genetic Traits from Extinct Species Remain in Modern Human Bodies

Growth Hormone Receptor Variant Raises Cell Proliferation by 39%

A study has revealed that genetic variants inherited from Neanderthals, who went extinct about 40,000 years ago, may influence modern human muscle mass as well as the shape of the jaw and teeth.

Recently, an international research team, including the Max Planck Institute for Evolutionary Anthropology in Germany and Karolinska Institutet in Sweden, reported in the international journal "Current Biology" that the genetic characteristics of the growth hormone receptor (GHR) in Neanderthals are linked to physical traits in modern humans.

A study has found that genetic variants inherited from Neanderthals may influence modern muscle mass as well as jaw and dental morphology. Pixabay

Growth hormone is involved in the development of muscles and bones, while the growth hormone receptor receives hormone signals on the cell surface and transmits them into the cell. The researchers administered the same amount of growth hormone to cells containing either Neanderthal-type or modern human-type growth hormone receptors, respectively. After five days, the cells with the Neanderthal-type receptor proliferated about 39% more than those with the modern human-type receptor.

To determine whether a similar difference occurs in the human body, the research team used biobank data from the United Kingdom, Finland, Japan, South Korea, and Taiwan. An analysis of approximately 1.13 million adults showed that individuals with one copy of the Neanderthal-type growth hormone receptor gene weighed an average of 285 grams more than those without the variant. Of this, arm and leg muscle mass was about 150 grams greater, and lean body mass in the trunk was about 121 grams higher.

Subtle differences were also observed in the jaw and teeth. People with the variant tended to have a slightly different shape in part of the lower jaw and relatively shorter tooth roots. These characteristics are somewhat similar to those seen in Neanderthal fossils.

On the other hand, analysis of data tracking over 6,600 children from birth to age 11 found no distinct association between the variant and growth indicators such as height and weight. The researchers suggested that the effects of this variant may become more pronounced after puberty than during childhood.

A reconstructed model of a Neanderthal. Neanderthal Museum

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