Q15
(a) Planaria, insects, octopus arid vertebrates all have eyes. Can we group eyes of these animals together to establish a common evolutionary origin? Justify your answer.
(b) “Birds have evolved from reptiles”. State evidence to prove the statement.
Solution
(a) The eyes seen in planaria, insects, octopus and vertebrates vary greatly in their structure. These Organisms can be used for studying evolution of eyes as the eyes of planaria are simple without lens, insects have compound eyes and vertebrates have highly specialised eyes. However, all of them perform the same function, that is, vision. Thus, a common evolutionary origin can be established.
(b) Birds have evolved from reptiles as the connecting link between reptiles and birds is Archaeopteryx (flying dinosaur). Also, there are some similarities in birds and reptiles. Birds have a four-chambered heart/ which is also a feature of some reptiles. Both birds and reptiles have separate sexes and internal fertilization occurs in both.
