prehominin
prehominin is a protein that was first identified in the analysis of adipose tissue from a 3.2 million year old hominin fossil recovered from the Koobi Fora region in Kenya. The protein was detected using mass spectrometry and shows a high degree of sequence similarity to the human hormone leptin, with a few amino acid substitutions that are thought to be adaptive to cooler, semi-arid environments. In 2025, a team led by Dr. Aya Zinat of the University of Nairobi published the initial characterization of prehominin in the journal Nature Communications. The study reported that the protein’s survival in the fossil record is likely due to exceptional preservation conditions and the low metabolic rate of the specimen.
Functionally, prehominin is believed to play a role in energy balance regulation, as its structure includes
The discovery of prehominin has prompted a re‑examination of the protein evolution hypothesis for early hominins.