According to Darwin, the organic evolution is due to

• intraspecific competition

• interspecific competition

• competition within closely related species

• competition within closely related species

B.

interspecific competition

Darwin stated that the organic evolution is due to interspecific competition. it is the competition between members of different species. Intraspecific competition occurs amongst members of the same species for obtaining optimum amounts of their food, shelter, mate, water, light, species etc. Closely species compete cannot cause evolution. Reduced feeding efficiency in one species due to the presence of interfering species is due to strugle for existance.