A large population of Arabidopsis epigenetic recombinant inbred lines (epiRILs) growing in a common garden. FABRICE ROUX
A central tenet of evolution is that small changes in an organism’s genome can be passed on to subsequent generations. Generally, we accept that this happens through the DNA sequences: small, random mutations are inherited by offspring. Indeed, many inherited characteristics, such as fruit color, flower shape, body size, or the direction a snail’s shell whorls are encoded in genes, but they do not always obey the simple laws of Mendelian inheritance. While transposable elements, extragenomic DNA, and—as was the case for the hawkweed that tormented Gregor Mendel himself—parthenogenesis can explain some of these anomalies, recently the spotlight has fallen on another type of inheritance altogether—epigenetic modifications.
Frank Johannes at the University of Groningen in The Netherlands has been trying to understand the intricacies ...