In a study published on Wednesday April 30, 2025 the proceedings of the Royal Society B, Dr. Masumoto-Oda and her team compared the healing rates of humans, chimpanzees, monkeys, and mice. They found that humans took more than twice as long to heal a wound than any of the other mammals tested. The slow healing trait might have been a result of an evolutionary trade-off that humans. The study recruited 24 patients who were having skin tumors removed at the University of the Ryukyus Hospital, 5 chimpanzees were observed at the Kumamoto Sanctuary of the Kyoto University Wildlife Research Center. The Skye's monkeys were observed as primates by having them anesthetized and then researchers would surgically wound them and then monitor their healing. But do not be alarmed. Dr. Matsumoto-Oda said that "as a field researcher, I personally believe that invasive studies should be minimized as much as possible" and later discussed that the surgical wounds were no bigger than the average bite size wounds that would occur in the habitats between the species. The results consisted of humans healing wounds more slowly than other animals, and said that they regrew skin at about a quarter of a millimeter per day, on average. There was more consistency between the healing rates of the animal subjects including the chimpanzees, and that they showed no significant difference in the speed to regrowing skin per day among different primates. They grew it at about 0.62 millimeters per day. Elaine Fuchs who was a stem cell biologist at the Rockefeller University who studied the skin growth and repair was not involved in the research itself, however, said that the results were what she would have expected. This was being the skin healing depends on hair, each hair grows from a hair follicle, which is a house for stem cells. Regularly stem cells would just produce more hair, however since skin is regrowing instead she said that when the epidermis is wounded it is really the hair follicle stem cell that performs the repairing. Since animals are normally furry they are covered in follicles, which can help heal wounds more quickly than in humans. Since humans have very puny hair follicles, they have lost their efficiency to repair wounds as quickly. This article was very interesting to learn about because I had never fully known that animals were able to heal quicker than humans due their higher amount of hair follicles for their fur. It is fascinating to know that over time loosing the access hair on the human body has prevented us from healing quicker.
