The human body has few vestigial features from anatomical, physiological to behavioral. vestigial is nothing but an organ of the human body that has become functionless in the course of evolution. Human evolution is the main reason why many parts become vestigial. There are more than 100 vestigial anomalies in humans. Here we listed a few
Wisdom teeth are said to be vestigial organs. A variety of habitats came into existence after human species migrated out of Africa and on the other hand human civilizations also developed. Simultaneously, humans started to eat soft and processed foods which slowly eliminated the need for large and powerful jaws. Humans’ jaw size and molars, particularly the third molars or wisdom teeth, reduced with evolution. And also wisdom teeth are hereditarily absent.
The nictitating membrane or third eyelid is a transparent eyelid present in some animals. It is still a part of the eye in some mammals, including the gorillas. In one of the human species’ closest relatives, chimpanzees, the plica semilunaris also seems to be vestigial. The nictitating membrane acts as protection against moisture and also conceals the iris from predators. It is unclear why the nictitating membrane in humans is absent but changes in habitat and eye physiology may have implications.
3.Palmar Grasp Reflex
Palmar grasp reflex is an involuntary response present in a newborn. It develops when the fetus begins to grasp the umbilical cord in the mother’s womb i.e early in the 16 weeks gestational age. Research says that human newborns could hold their weight for at least 10 seconds when hanging by their hands from a horizontal position. Monkey infants possess a similar involuntary grasping behavior but they were able to hang from one hand for more than half an hour. Some studies say grasp reflex may retain important functions in humans.
The Auricular muscles are the extrinsic and intrinsic muscles of the auricula, it connects the skull and scalp and helps to move the auricula as a whole. The auricular muscles also connect the pinna or the visible part of the ear. The ear movements produced by this muscle play a role in the expression of emotion and sound localization. Whereas in humans the muscles are nonfunctional. However, some humans can wiggle their ears.
The human tail is also known as the vestigial tail. The human embryo possesses a tail in the sixth week of gestation. However, in the following week of development, the tail disappears and later it forms a tailbone or coccyx. Even now rarely human infants are born with a vestigial tail. According to medical literature, typically tails are harmless but some are associated with spina bifida. Tails can be removed through surgery without complication.