Overview
- A study published Wednesday found two amino-acid changes unique to the Neandertal growth hormone receptor and reported the variant entered Homo sapiens through interbreeding about 47,000 years ago.
- Lab tests that engineered cells to carry the Neandertal receptor showed about a 39–40% stronger proliferative response when stimulated by pituitary growth hormone.
- Analyses of more than 1.1 million adults across multiple biobanks linked the variant to modest average gains of roughly 0.25–0.27 kg of muscle and about 0.3 cm in height for carriers.
- The effect appears after childhood with no association up to age 11, and carriers also show subtle craniofacial and dental differences such as a shorter rear lower jaw and shorter tooth roots.
- Authors stress the variant is one of many genetic factors, has a small effect size, offers evolutionary insight into how archaic DNA can shape traits, and has no current clinical application.