Vestigial organs are parts of the body that have lost their original function through evolution. These organs may have been useful to our ancestors, but are now no longer needed due to changes in our environment or lifestyle. One of the examples of vestigial organ in humans is: 


Appendix: The human appendix is a small, finger-shaped pouch attached to the large intestine in the lower right side of the abdomen. 


Appendix
Appendix


It is a vestigial structure, meaning that it has lost its original function over time as humans have evolved. Although its function in humans is not entirely clear, it is believed that the appendix may have played a role in digestion in the past, particularly in aiding the breakdown of cellulose in plant-based diets. 

•However, as humans have evolved to consume more animal-based diets, the need for the appendix may have decreased. 

•The appendix has also been suggested to have a role in the immune system, as it contains lymphatic tissue that produces antibodies and helps to fight infections. 

•In some cases, the appendix can become inflamed and infected, a condition known as appendicitis, which can cause abdominal pain, nausea, and fever. If left untreated, appendicitis can lead to serious complications and may require surgery to remove the appendix.

•The appendix is a small, tube-like structure attached to the large intestine. It is thought to have played a role in digesting tough plant material in our ancestors, but it no longer serves a functional purpose in humans. 

•This internal body part became non functional because as people evolved with time and gained the knowledge of different types of food available to them, the gradually terminated the consumption of cellulose based plant products. 

•Hence, appendix stopped its function of cellulose digestion and became useless. As the evolutionary trend suggests that organs and body parts which are used very often becomes specialized in its work.

•Surgical removal of appendix due to appendicitis does not have any effect on normal functioning of human body whatsoever.