Different subpopulations of a plant species can have distinct traits, varying in size, seed count, coloration, and so on. The primary source of this variation is genes: different versions of a gene can lead to different traits. However, genes are not the only determinant of such traits, and researchers are learning more about another contributor: epigenetics. Epigenetic factors are things that regulate genes, altering their expression, and like genes they can be inherited from generation to generation, even though they are independent of the actual DNA sequences of the genes.