Abstract
Epigenetic modifications include a variety of molecular mechanisms such as DNA methylation, histone modification, and non-coding RNAs that change the expression of a gene without altering its DNA sequence. Such modifications can persist, via mitosis in a developing organism, or, even via meiosis from one generation to the next. The former phenomenon, which we here call persistence, undoubtedly underlies the ways in which various tissues and organs become differentiated; the latter, which we recognize as true inheritance, has the potential to greatly expand our understanding of how evolution works, since it implies that parents pass on much more than their genes to their offspring.
First published in Encyclopedia of Evolutionary Biology (1st ed.) 2016. Republished in Encyclopedia of Evolutionary Biology (2nd ed.) 2025.