Q1 Page 151 - Chapter 9 Class 10 - Heredity and Evolution

What factors could lead to the rise of a new species?

Answer:

Factors that would lead to the rise of a new species are:

1. Natural Selection
2. Genetic Drift
3. Geographical isolation of a population (lack of gene flow)

This can be explained as follows:

Natural selection:

• The variation became a common characteristic due to its survival advantage .
• This is known as Natural Selection - An adaptation to fit in the environment better.
• A new species emerged as a result of natural selection.
• Natural Selection was introduced as a concept by Charles Darwin.

Genetic drift:

• Accidents in small populations can change the frequency of some genes in a population
• This is known as Genetic Drift .
• This can result in the emergence of new species.

Geographical isolation:

• Here, a geographical divide (a river) separates the populations .
• Since the individuals of different populations cannot mate easily, gene flow (movement of genes from one population to another) between them will decrease.
• The individual population will evolve differently, forming different species .