3: Mutation
( \newcommand{\kernel}{\mathrm{null}\,}\)
Mutations are any change in DNA nucleotide sequence. Because DNA stores information in the sequence of bases, a change in a base could (but does not always) have an effect on gene products. We already learned that genomes have variation; mutations are the source of that variation. In essence, without mutations there would be no diversity - within a species or between species!