Molecular evolution is the process of change in the sequence composition of
cellular molecules such as
DNA,
RNA, and
proteins across generations. The field of molecular evolution uses principles of
evolutionary biology and
population genetics to explain patterns in these changes. Major topics in molecular evolution concern the rates and impacts of single nucleotide changes, neutral evolution vs.
natural selection, origins of new genes, the genetic nature of complex traits, the genetic basis of
speciation, evolution of development, and ways that evolutionary forces influence
genomic and
phenotypic changes.