Question

Structure like eye evolved due to single change in DNA. Justify the statement

Answer 1

The evolution of a complex organ like an eye took place not by a single DNA change but in gradual steps, over generations.

Planaria was the first to show any signs of eye like structure. The eyes of planaria are just eye spots to detect light. Eyes in anthropoids or in case of insects are compound eyes which are made up of thousand of optical surfaces. Eyes of other higher animals are composed of single lens. In comparison human eyes are the most advanced because they are capable of recognizing colors and have a very good depth perception.
The evolution of eyes began with the formation of eye spots and was developed gradually into the more complex human eye structure.

Thus the formation of a complex structure like an eye took place by evolution from rudimentary organs, bit by bit over generations, and not by a single DNA change.