Researchers in the George Washington Uni examined the factors of hair variation among early humans. They used the wild lemurs' population (Indriidae) for the same. This research aimed to find the impacts of climate conditions, body size, and vision on hair evolution.
They found that Sifaka lemurs (native to Madagascar) developed much denser hair in dry and open environmental conditions. Researchers believe that the body hairs of early animals protected them from the powerful sun rays.
Lemurs living in colder regions have darker hair. It became the first-ever scientific evidence in animals for a classical natural pattern called Bogert's Rule. It states that the dark hair colors could help thermoregulation as they absorb heat from the sun.
Red hairs of lemurs help in enhanced color vision.
The researchers found that lemurs can have a range of colors and have patches of red hair on their bodies. Multiple evolutionary processes act on these traits, and the overall strength of its influence may vary in the species.
Researchers said that they conducted a study at GW on lemurs. In the research, lemurs exhibit an upright human posture and live in many biosystems, the same as early human beings. So the results provided a unique answer to the human hair evolution mystery.