Question

(i) Planaria, insects, octopus and vertebrates all have eyes. Can we group eyes of these animals together to establish a common evolutionary origin? Justify your answer. (ii) "Birds have evolved from reptiles" State evidence to prove the statement.

Answer 1

The eyes seen in Planaria, insects, octopus and vertebrates vary greatly in their structure. The eye of Planaria is simple without lens, insects have compound eyes and vertebrates have highly specialized eye however, all of them perform same function, that is, vision. Thus, a common evolutionary origin can be established. Birds can be said to have originated from reptiles as both have some features in common. Birds have four chambered heart (also found in some reptiles), both have separate sexes and internal fertilization occurs in both. Archaeopteryx was one such species with reptilian body and wings which laid the foundation of establishing these similarities.