Question

What are the suggested reasons for the population explosion? How is Darwin's concept of evolution different from that of De Vries?

Answer 1

• The rapid increase in population over a relatively short period of time is called the population explosion.
  
• Two main factors for the increase in human population:-
• (A) Decrease in death rate mainly maternal mortality rate (MMR) and infant mortality rate (IMR).
• (B) Increase in the span of life.



Darwin's concept	De Vries concept
1) Variations cause minor heritable changes in traits in the species.	1) Mutations cause large differences in characters or traits of an organism which occurs suddenly.
2) Evolution is gradual.	2) Evolution occurs in a single step mutation.