features that were useful to an anceteral organism but are not useful to a modern arganism that has them are s

Question

haha another science one...

Answer 1

vestigial structures : )


For instance the human appendix.

Answer 2

Vestigial.

But the definition you give is quite misleading - to be vestigial it's not required that a feature has no use at all, just that it does not have the use it does in the ancestral organism.

For example it's now believed that the appendix has some small use in the immune system, however it does not have the role in digestion that it plays in ancestral organisms.