Gene mutation turned humans in to long-distance runners
AMERICAN researchers found that two to three million years ago, the functional loss of a single gene made humanity into the best long-distance runners in the animal kingdom.
In a paper to be published in the Proceedings of the Royal Society B, researchers at University of California (UC) San Diego School of Medicine reported on studies of mice engineered to lack the same gene, called CMAH.
At roughly the same time as the CMAH mutation took hold, human ancestors were transitioning from forest dwellers to life upon the arid savannah of Africa, according to the study.
While they were already walking upright, the bodies and abilities of these early hominids were evolving dramatically with major changes in skeletal biomechanics and physiology that resulted in long, springy legs, big feet, powerful gluteal muscles and an expansive system of sweat glands that were able to dissipate heat more effectively than other larger mammals. Such changes helped fuel the emergence of the human ability to run long distances, to hunt in the heat of the day when carnivores were resting and to pursue prey to their point of exhaustion, a technique called persistence hunting.
A team lead the paper’s senior author Ajit Varki, a Distinguished Professor of Medicine and Cellular and Molecular Medicine, investigated how the genetic difference might have contributed to the origin of Homo, the genus that includes modern Homo sapiens and extinct species like Homo habilis and Homo erectus.
Those observations suggest CMAH loss contributed to improved skeletal muscle capacity for using oxygen.