Darwin in his 'Natural Selection Theory' did not believe in any role of which one of the following in organic evolution
Discontinuous variations
Parasites, predators and natural enemies
Survival of the fittest
Struggle for existence
The idea of spontaneous generation was first refuted by
Contribution of scientist : August Weismann
A closed system is one which
Darwin judged the fitness of an individual by
Vestigial organ in man is