https://www.sciencealert.com/scientists-observe-epigenetic-memories-passed-down-for-14-generations-most-animal

The most important set of genetic instructions we all get comes from our DNA, passed down through generations. But the environment we live in can make genetic changes, too.

Last year, researchers discovered that these kinds of environmental genetic changes can be passed down for a whopping 14 generations in an animal – the largest span ever observed in a creature, in this case being a dynasty of C. elegans nematodes (roundworms).