Transgenerational epigenetic inheritance is the transmission of epigenetic marks from parent to child. Transgenerational epigenetic inheritance does not alter DNA of genes. To be at all useful in humans in terms of evolutionary fitness epigenetic alterations on which transgenerational epigenetic inheritance is founded would have to be systematic Both the wider organism and sperm cells and egg cells would have to be affected together by a class of epigenetic alterations. Many illnesses that are classed as brain diseases such as autism, major depression and schizophrenia would have to have systematic effects which in fact these illnesses do have. Parents of children with autism, for example, very frequently state that their children are systematically ill and that all physical complaints of their children have to be addressed. Individuals with schizophrenia have much reduced life spans. The heritability of Alzheimer’s disease ranges from 49% to 79%. Alzheimer’s is classified as a brain disease but individuals with Alzheimer’s disease are ill in about every way imaginable.
Transgenerational epigenetic inheritance where stuff just happens to gametes and that stuff can be transgenerationally passed along would be totally useless in terms of human evolutionary fitness. Phenotypes are selected by evolution. There are cultural traits which are very difficult to alter but which can be altered. If such cultural traits had a biological basis inheritance of such cultural traits would be feasible. Holding that there is a biological bases for cultural traits is usually viewed as racist, however, given the biological basis of cultural such traits depends on transgenerational epigenetic inheritances then though there are biological bases for cultural traits such cultural traits are mutable over the course of generations rather than basically immutable due to such cultural traits being hardwired into DNA.
Any familiarity with history at all would disclose that women in the West are acting much differently than women acted three hundred years ago. Women in the elite classes three hundred years did not all hold all was oppression and all secretly long to be scientists, head of businesses and heads governments but rather held there were various terrific advantages to being women of the elite classes in 1720. The biology of women made being women of 1720, at least of the elite classes, very attractive to women in 1720, however, as is also clear cultural traits of women have not been immutable over the last 300 years. With transgenerational epigenetic inheritance various cultural traits of women can be both biologically based and mutable. Women as androgynous men will never work for women wholesale, DNA of women will always be different than the DNA of men, however, women as lawyers, women as doctors, women in business etc can and has worked for women.
What distinguishes humans from other animal species could be that transgenerational epigenetic inheritances are very prevalent in humans.