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.

Explanation:

Cladograms rely on shared derived characteristics to show common ancestry. The option that links birds and reptiles through a shared evolutionary trait is the best evidence. Reptiles related to mammals, bird diversification, and birds being warm-blooded like mammals do not directly support a shared ancestor between birds and reptiles. However, feathers evolving first in reptiles shows a derived trait passed to birds, confirming a common ancestor.

Answer:

Feathers are a derived characteristic that first evolved in reptiles.