Which is NOT a vestigial structure? Appendix Brain Wisdom teeth Rewatch

## Step 1<br />Vestigial structures are parts of an organism that are reduced from or similar to an ancestral form. They are typically non-functional or have a reduced function compared to their original function in the ancestral form.<br /><br />## Step 2<br />The appendix is considered a vestigial structure. It is a small pouch attached to the large intestine and has no known essential function in humans.<br /><br />## Step 3<br />Wisdom teeth are also considered vestigial. They were more functional in our ancestors who had a rough diet and needed extra grinding power. However, in modern humans, they often cause dental problems and are often removed.<br /><br />## Step 4<br />The brain is not a vestigial structure. It is a vital organ that controls all the functions of the body and mind. It is essential for consciousness, thought, emotion, and coordination of the body's functions.