Which one of the following sequences was proposed by Darwin and Wallace for organic evolution : -
A
Overproduction, variations, constancy of population size, natural selection
B
Variations, constancy of population size, overproduction, natural selection
C
Overproduction, constancy of population size, variations, natural selection
D
Variations, natural selection, overproduction, constancy of population size
The answer is C.
Solution
The main points of the Darwin–Wallace theory of natural selection follow a logical sequence: 1. Overproduction: organisms produce far more offspring than can survive (geometric increase). 2. Variations: individuals of a population differ from one another, and many variations are heritable. 3. Constancy of population size: in spite of overproduction, population sizes remain roughly constant because resources are limited, which leads to a struggle for existence. 4. Natural selection: individuals with favourable variations survive and reproduce more (survival of the fittest), and over generations new species arise. So the sequence is overproduction, variations, constancy of population size, natural selection.
ConceptSequence of Darwin's arguments
Evolution in past papers
143 questions from this chapter have appeared across 27 exam years.
