Question

Explain how individual variations allow evolution to occur?

Short answer

Individual variations that are beneficial for an organism's survival are transferred to the next generation. Subsequent transfers leads to the stabilization of the variation and a new species is developed; this results in evolution.

Step-by-step solution

Variation and evolution

Evolution is a continuous process which helps in survival of an organism in the changing environment. Variation resulting from sexual reproduction is passed on from generation to generation as these characters are gene linked and result in variation.

Explanation

In mutation, some variation occurs due to sudden changes in the genes, which alter the genetic makeup of an organism. If the variation is favourable for the organism's survival, the nature helps in multiplication of organisms with that new character.

As the theory says survival of the fittest it is nature that selects the fittest species or character over period of time. The new favourable variation is transferred to next generations through sexual reproduction. This leads to stabilization of that new character and evolution of the organism.

Example

Giraffe can be taken as an example.They were considered to have short necks and graze on the ground for food. But with change in environment, vegetation vanished from the ground so giraffes had to stretch its neck to get food from tall trees which resulted in long necks of the giraffes.

This was an individual characteristic but was inherited as it had survival advantage .Thus there is a possibility that there could have been only one giraffe who could stretch its neck, but this individual characteristic was inherited from generation to generation, and allowed evolution to occur as a mode of natural selection. Now, giraffes are famous for their long necks.