Mutation is a sudden heritable change in an organism which is generally due to change in
the base sequence of the nucleic acid in the organism's genome.

Microbial experiments show that pre-existing advantageous mutations when selected will
result in formation of new phenotypes. Over few generations, this would result in speciation. Thus, resulting in changed frequency of genes and alleles.

Natural selection is a phenomenon by which organisms possessing heritable variations
enabling their better survival reproduce and leave greater number of progeny than their
counterpart.

It can lead to stabilisation (in which more individuals acquire mean character value)
directional change (more individuals acquire value other than the mean character value) 0 132
disruption (more individuals acquire peripheral character value at both ends of the
distribution curve)