Neanderthal Gene Variant Linked to Increased Muscle Mass in Humans

Researchers at Karolinska Institutet have identified a genetic variant inherited from Neanderthals that may increase muscle mass in modern humans. According to the institution, this specific genomic remnant influences how muscle tissue develops and maintains itself, providing a biological link between extinct hominids and contemporary human physical traits.

The finding stems from the study of archaic DNA integrated into the human genome. While Neanderthals disappeared tens of thousands of years ago, their genetic material persists in non-African populations through interbreeding events that occurred as early modern humans migrated out of Africa. According to Karolinska Institutet, these inherited variants continue to affect various physiological functions, including musculoskeletal growth.

The identified variant operates by altering the expression of genes responsible for muscle fiber regulation. By analyzing the genomic sequences of modern humans and comparing them to sequenced Neanderthal genomes, the researchers isolated a specific marker associated with higher muscle mass. This suggests that certain physical advantages or characteristics in the modern population are direct legacies of Neanderthal biology.

Neanderthal DNA and Musculoskeletal Influence

The presence of Neanderthal DNA in modern humans is not uniform across the genome. Instead, it exists in “deserts” and “islands,” where some regions were purged by natural selection while others were preserved because they offered an evolutionary advantage. According to the research from Karolinska Institutet, the variant linked to muscle mass was preserved, indicating it likely provided a benefit to early humans adapting to new environments.

Muscle mass is regulated by a complex network of proteins and signaling pathways. The Neanderthal variant influences these pathways, potentially increasing the density or size of muscle fibers. This genetic inheritance differs from mutations that occur spontaneously in modern humans, as it represents a functional block of DNA that was already “tested” through the evolutionary history of the Neanderthal species.

Evolutionary Context of Archaic Variants

Neanderthals were characterized by more robust skeletal structures and greater muscle mass than early Homo sapiens. According to the findings, the transmission of these traits through interbreeding allowed modern humans to integrate some of this robustness into their own biology. This process helped populations adapt to the colder, harsher climates of Eurasia, where increased muscle mass and different metabolic rates were advantageous for survival.

The research highlights that these genetic contributions are not limited to physical strength. Other Neanderthal variants have been linked to immune system responses, skin pigmentation, and blood clotting. The muscle-related variant is part of a broader pattern where archaic DNA helps modern humans modulate their physiology to suit specific environmental pressures.

Implications for Modern Health Research

Identifying the specific mechanisms by which this variant increases muscle mass provides a new target for medical research. According to the Karolinska Institutet framework, understanding how these archaic genes regulate muscle growth could lead to better insights into muscle-wasting diseases or sarcopenia, the age-related loss of muscle mass.

While the variant may increase muscle mass, the researchers emphasize that genetic traits do not act in isolation. The final physical outcome depends on the interaction between this Neanderthal variant and the rest of an individual’s genome, as well as environmental factors such as nutrition and physical activity.

Further study is required to determine the exact percentage of the population carrying this variant and whether it correlates with specific health outcomes beyond muscle volume. The research marks a continuing effort to map the “ghost” lineages within the human genome to understand the biological origins of human diversity.