Biology
Why does the human appendix still exist?
Quick fact
The appendix is a small, finger-shaped pouch attached to the large intestine that contains a high concentration of lymphoid tissue and acts as a reservoir for beneficial gut bacteria.
Why this is interesting
Your appendix was once dismissed as a evolutionary leftover—but recent research shows it's actually a 'safe house' for good bacteria, repopulating your gut after infections wipe out your microbiome.