Question

Planaria, insects, octopus and vertebrates all have eyes. Can we group of these animals together to establish a common evolutionary origin? Justify your answer.

Answer 1

Planaria, insects, octopus and vertebrates all have eyes. Though, the eyes in Planaria, insects, octopus and vertebrates vary greatly in their structure. These organisms can be used for studying the evolution of eyes as the eye of Planaria is simple without a lens, insects have compound eyes and vertebrates have a highly specialized eye.

Only presence eyes cannot be considered as a criterion to group together these animals or establish common evolutionary origin. A lot of other characteristics like cellular organisation, the complexity of body structure, the presence of notochord etc. are used for the purpose of grouping organisms together.