Many people have wondered, and even worried about their health, due to the wrinkling of their hands and feet, which can resemble dry, shriveled grapes after soaking in water.
A new study has found that fingers and toes wrinkle when submerged in water to help us grip or hold onto wet objects.
When a person’s hands and feet are soaked in water, wrinkles gradually form at the tips of the fingers and toes. Scientists previously believed that this wrinkling phenomenon was due to the outer layer of skin absorbing and swelling with water. However, recent research reveals that the nervous system actively controls the wrinkling of the skin by constricting blood cells beneath the skin.
The nervous system’s control over this process suggests that the wrinkles on the tips of fingers and toes serve a specific purpose.
Fingers wrinkle after prolonged exposure to water.
According to Live Science, researcher Tom Smulders, an evolutionary biologist at Newcastle University (UK), stated: “This familiar phenomenon is not a side effect of the skin’s nature on fingers and toes, but rather a functional trait that may have been selected during the process of evolution.”
Through experiments, Smulders and his colleagues discovered that wrinkled fingers can grip objects better in wet conditions, similar to how tread patterns on tires help them grip the road. Another possibility is that the wrinkling alters skin properties, such as elasticity and tackiness, which enhances grip when fingers are wet.
Smulders suggests that this could be an evolutionary trait that helped humans gather food from wet vegetation or rivers. The fact that this effect also occurs in toes (where wrinkled skin helps feet grip the ground and other surfaces better) indicates that it might have provided an advantage for our ancestors to move more effectively in the rain.
The research team further found that wrinkled fingers do not seem to provide any advantage when gripping dry objects. “This raises the question of why we haven’t evolved to have permanently wrinkled fingers. Our initial hypothesis is that this phenomenon may reduce sensitivity in the fingertips or increase the risk of injury when gripping objects. More research is needed,” Smulders remarked.
This scientist believes future studies should also investigate whether a similar phenomenon occurs in other animals, including both primates and non-primates. This could shed light on the timing and origins of this evolutionary trait.
