The vestigial organs of the human body are anatomical structures that have lost most or all of their original function throughout evolution. These organs are remnants of evolutionary ancestors and do not play a relevant role in the current physiology of human beings. Although they have lost their primary function, vestigial organs still remain in the human body, providing evidence of evolution and adaptation over time.
What are vestigial organs?
Vestigial organs are anatomical structures that, through the evolutionary process, have lost their original function in the species. These organs are usually residues of organs that played an important role in the ancestors of the species, but that over time have ceased to be necessary due to changes in the environment or way of life.
Characteristics of vestigial organs:
- They do not fulfill a relevant function in the current physiology of the species.
- They are usually reduced or modified versions of organs that had a clear function in species above.
- They can be present in the human body without causing health problems, but in some cases they can lead to complications if pathologies associated with them develop.
10 Examples of vestigial organs in the human body
Below are 10 examples of vestigial organs in the human body, which are vestiges of the evolution of our species:
1. Appendix
The appendix is one of the best-known vestigial organs. It is a small pouch located at the junction of the large and small intestine. In humans, the appendix does not play a major role in digestion and its actual function remains a matter of debate. Although it can become inflamed in a disorder known as appendicitis, its removal does not significantly affect health.
2. Auricular muscles
The auricular muscles are small muscles found on the outside of the ears. These muscles are vestigial in humans, since our ancestors could move their ears to orient themselves towards sounds. Today, most people have no control over these muscles, indicating their vestigial function.
3. Wisdom teeth
Wisdom teeth, also known as third molars, are teeth that typically appear in the back of the mouth during adolescence or young adulthood. In our ancestors, who ate a harder, more fibrous diet, these molars were useful for grinding food. However, these days, most people do not have enough space in their mouth to accommodate these teeth, which can lead to dental problems if they are not extracted.
4. Coccyx
The coccyx is a series of vertebrae fused at the end of the spine, which is a vestige of the tail that our ancestors had. In modern humans, the coccyx does not serve any important function and often causes discomfort or pain in some people, especially when injured.
5. Body hair
Body hair in humans is a vestige of our evolution. In our ancestors, body hair provided protection from the cold and helped regulate body temperature. However, in modern humans, body hair has a much less relevant function and in most cases is more aesthetic than functional.
6. Palmaris longus muscle
The palmaris longus muscle is a muscle in the forearm that extends from the elbow to the palm of the hand. In many humans, this muscle is absent or rudimentary, indicating its vestigial nature. In our ancestors, this muscle was important for climbing and hanging from branches, but in modern humans its function is minimal.
7. Denominator
The denominator is a muscle in the neck that extends from the collarbone to the jaw. In our ancestors, this muscle was used to move the head from side to side more easily. In modern humans, the denominator is a small, poorly developed muscle, making it an example of a vestigial organ.
8. Plantaris longus muscle
The plantaris longus muscle is a muscle on the sole of the foot that extends from the heel to the toes. In some humans, this muscle is absent or very small, indicating its vestigial nature. In our ancestors, this muscle was important for gripping the feet, but in modern humans its function is minimal due to our current lifestyle.
9. Male mammary glands
Men have mammary glands that are vestiges of embryonic development. In humans, these glands usually do not develop fully, but in some cases they can become swollen due to hormonal imbalances or other medical conditions. Although men do not produce milk, these glands are a vestige of human evolution and development.
10. Male and female pelvis
The pelvis of human beings presents differences between men and women due to differences in reproductive function. However, the structure of the human pelvis is a vestige of evolution. In our ancestors, the shape of the pelvis was more related to walking on four limbs, but with the evolution towards bipedalism, the pelvis adapted, leaving vestiges of that transition in the bone structure.
These are Just a few examples of vestigial organs in the human body, reminding us of our evolutionary history and how we have changed and adapted over time.