Question

What is the correct sequence for organic evolution as proposed by Darwin

Answer 1

Answer:

correct sequence for organic evolution as proposed by Darwin are as follows

1 ) Over production

Maximum reproduction will cause exponential / geometric growth.

• Example 1 star fish - 1 lac eggs / year - 1 lac star fish - 1 lac × 1lac eggs

2) Struggle for existence

• Population size remains constant except for seasonal variation due to limited resources.
• Survivors survive at the cost of death of others.

a) Intraspecific struggle

• Between individuals of same species.
• For food , shelter and mating.
• Most acute type of struggle.

b ) Interspecific struggle

• Between different species.
• For food and shelter.
• Most potent force for organic evolution.

c) Environmental struggle

• Faced by everyone.
• Example - natural calamity

3) Variation and Heredity

• Individuals in a population differ in variations which are inbuilt and hence heritable.
• Example - Neck height of girraffe.

4) Natural selection / Survival of the fittest

• Fitness is the ability to adapt and get selected by nature.

5) Specification

• Continuous selection of adaptive (+ve) variant generation after generation will form new species.