Question

Why do a chicken embryo and a cow embryo look very similar even though the adults do not

Answer 1

The answer is : They are distantly related so their development is similar. They have different genetic materials.

Answer 2

Answer:

Embryonic development is the initial stage in organism's  life. Many animal and birds species shows similar embryonic growth. This indicates that they are evolved from a common ancestor. Differences in features and structures in adulthood is because of genetic information present in the embryo and the process of subsequent adaptations for the purpose of evolution.