A recent study published in Nature Neuroscience magazine indicates that a significant experience or event could alter DNA in sperm and essentially pass on that memory to future generations!
Here is some background on the significance of this discovery: Lamarck was a 19th century scientist who proposed the idea of use and disuse, and that behavior could affect the phenotypes, genotypes, or behavior of offspring. However, throughout the years, this theory has largely been rejected, but this new paper could suggest otherwise!
A quick summary on BBC:
The original paper: