Case Study/Passage Based Questions:
Question 1:
Darwin found the varieties of finches that in travelled to Galapagos Islands and observed variations in them.

(i) What role does an individual organism play as per Darwin’s theory of natural selection?
(ii) How did Darwin explain the existence of different varieties of finches on Galapagos Islands?
(iii) What is “fitness of an individual” according to Darwin?
Answer
Ans.(i) An individual organism passes on the variations, mutations and adaptations from one generation to another.
(ii) Darwin explained it as the process of evolution of different species in a given geographical area starting from a point and literally radiating to other areas of geography (habitats), called adaptive radiation.
(iii) According to Darwin, “fitness of an individual” is the ability of an organism to survive and pass on its genes to future generations.