Years ago I came across an interesting study, but I've lost track of since.
Scandinavian scientists had concluded that DNA was being upgraded constantly.
Man produces sperm daily, meaning that even the previous day's 'experiences' were integrated into the sperm DNA codes.
Another reason why siblings can be different.
A female is born with her ovum, so nothing new is added....but a male's sperm is a ongoing genetic 'journal' of his life experiences.
This proves that genes are past experienced passed-on, but also that, through the male, these genes are being upgraded constantly.