Question

It can be seen on a cladogram that modern birds and reptiles share a common ancestor. Select the piece of evidence that best supports this idea.
Reptiles are also related to mammals.
Birds have evolved into many groups.
Feathers are a derived characteristic that first evolved in reptiles.
Birds have the derived characteristic of being warm blooded, like mammals.

Answer 1

Feathers are a derived characteristic that first evolved in reptiles.

Explanation: A shared derived trait (synapomorphy) like feathers linking birds and reptiles provides direct evidence of common ancestry on a cladogram.