Apes make monkeys of us - we're weaker, fatter and sweatier

Scimex: US and South African scientists compared human bodies with those of our closest ape relatives, bonobo chimpanzees, to gain insights into our evolution. They found we're less muscular overall, fatter and have less skin than bonobos, but it's not all bad - at least we evolved the ability to sweat profusely, which bonobos can't do. Human skin, fat, and muscle proportions differ significantly from those of bonobos, suggesting evolutionary factors that may have shaped the body structure of Homo sapiens, according to a study.


A lack of fossilized soft tissues precludes comparison of the musculature, fat distribution, and skin of human ancestors with modern humans. To investigate how evolutionary forces may have shaped human body composition over time, Adrienne L. Zihlman and Debra R. Bolter dissected 13 bonobos—rare members of the Pan genus that represent Homo sapiens’ closest living ape relatives—that had died of natural causes, and compared soft tissue composition with that of modern humans. Compared with bonobos, humans have increased body fat, decreased muscle mass, and decreased skin mass. Further, the authors found that humans display an evolutionary redistribution of muscle mass to the lower limbs. Evolutionary factors such as variable calorie intake in new environments may have led to an increase in body fat percentage. Lengthened lower limbs with the development of bipedalism may have driven the shift of muscle mass to the lower limbs, and humans’ ability to sweat may have led to changes in skin and hair characteristics that may have freed early Homo species from restricted temperature niches. The results suggest that various evolutionary pressures likely shaped modern human body composition, according to the authors.