Mutation, a driving force of evolution, is a random change in a population's gene pool.
Mutations give rise to new alleles; therefore, they are the source of variation in a population.
Mutations may be harmful, but they may also be beneficial.
Evolution is responsible for both the remarkable similarities we see across all life and the amazing diversity of that life – but exactly how does it work? The principles of evolution are as follows:
Mutation : Mutation, a driving force of evolution, is a random change in a population's gene pool. It is a change in the nature of the DNA in one or more chromosomes. Mutations give rise to new alleles; therefore, they are the source of variation in a population. Mutations may be harmful, but they may also be beneficial.
An example of Gene flow
Gene flow and evolution: Another mechanism of evolution may occur during the migration of individuals from one group to another. Gene flow is the transfer of alleles from one population to another population through immigration of individuals. When the migrating individuals interbreed with the new population, they contribute their genes to the gene pool of the local population. This establishes gene flow in the population.
Genetic drift: Another mechanism for evolution is genetic drift. Genetic drift occurs when a small group of individuals leaves a population and establishes a new one in a geographically isolated region.
Natural selection: Clearly, the most important influence on evolution is natural selection, which occurs when an organism is subject to its environment. The fittest survive and contribute their genes to their offspring, producing a population that is better adapted to the environment. The genes of less-fit individuals are eventually lost. The important selective force in natural selection is the environment. Therefore, natural selection tends to remove the less–fit individuals, allowing more–fit individuals to survive and form a population of fit individuals.