According to darwin's theory of natural selection, individuals who survive are the ones best adapted for their environment. Their survival is due to the

adaptations that are occurring in individuals due on a small scale to mutations and being expressed due to the environment contribute variation of alleles and traits to the overall population of the species. (Basically variation)

image result for describe the various types of gene mutationsghr.nlm.nih.gov

the types of mutations include: missense mutation: this type of mutation is a change in one dna base pair that results in the substitution of one amino acid for another in the protein made by a gene. nonsense mutation: a nonsense mutation is also a change in one dna base pair.

explanation: