Genetic variations are the differences in DNA among individuals of the same species. These variations are very important because they are the raw material for evolution — without them, evolution could not happen.
Here’s how genetic variation contributes to evolution, explained:
- Variation creates differences:
Every individual in a species has slightly different genes. These differences can affect traits like color, size, speed, or resistance to disease. - Sources of variation:
- Mutations: Small, random changes in DNA.
- Gene recombination: Mixing of genes during sexual reproduction (for example, when sperm and egg combine).
- Gene flow: When individuals move between populations, they bring new genes with them.
- Natural selection acts on variation:
In any environment, some variations give individuals an advantage — for example, better camouflage or stronger resistance to cold.- Those with helpful traits survive and reproduce more.
- Their offspring inherit these traits.
- Over time, these traits become more common in the population.
- Adaptation and evolution:
As generations pass, the accumulation of beneficial genetic variations leads to adaptation — the population becomes better suited to its environment.
Eventually, large changes can result in the formation of new species. - Example:
In a population of moths, some are light-colored and some are dark. If pollution darkens tree bark, the dark moths blend in better and are less likely to be eaten by birds. Over time, more dark moths survive and reproduce — this is evolution driven by genetic variation.
In short, genetic variation provides the differences that natural selection can act upon, allowing species to adapt, survive, and evolve over time.