• There's very little in our anatomy that has — or had — no purpose whatsoever.
• While there are a few things that might seem useless now, they exist because our ancestors once needed these features.
• The appendix isn't completely useless — recent research shows it might help harbor good bacteria that fight infections.
• Scientists have recently discovered that the interstitium, or the tissue surrounding our organs previously thought of as unremarkable, might actually be protective.

Your appendix

That extra ear hole

Wrinkly fingers

Junk DNA

"Useless" immune cells

Gut bacteria

Interstitium

The pink bit in your eye