Question

Explain Darwin's theory of evolution by natural selection. What were his assumptions and deductions?

Answer 1

Darwin’s theory explains evolution as the accumulation of favourable heritable variations through natural selection.

Assumptions and observations:

1. Organisms produce more offspring than can survive.
2. Population sizes remain relatively limited because resources are finite.
3. Individuals within a population vary, and some variation is heritable.
4. Individuals compete for food, space, and other necessities.

Deductions:

1. Overproduction and limited resources produce a struggle for existence.
2. Individuals with favourable variations survive and reproduce more successfully—the survival of the fittest.
3. Favourable traits are inherited and increase in frequency over generations.
4. Continued accumulation of differences can lead to the origin of new species.

Natural selection changes populations by favouring heritable variations that improve adaptation and reproductive success.