Recently a report was published in the journal Nature Neuroscience about an experiment where mice were taught to associate pain with a scent, and then the fear of this scent was passed on to their offspring and their offspring's litter without them having experienced the pain of the parent or grand-parent themself. If what this research indicates is true, then it could open up the flood gates to a new dimension of genetic research.
The key point to take from this research is that traits can be passed from parent to child and grandchild without there being an alteration of DNA! So there's another form of inheritance! This brings in to question one of the central dogmas in genetics that DNA is the only genetic material (in all species save for a few microbes). If this research is confirmed and an alternative mechanism for information transmission is defined, then it will open up a whole new way of looking at genetics and inheritance of traits, both physical and psychological and also various diseases.
This might be the first time such an idea has been proved without their being confounding genetic and environmental factors that might affect the results and there is evidence of physical changes in the brain too. But before we jump up and down like excited children, we need to be careful and see if the result can be reproduced in other mice strains and in other species. I expect they will.
Here's the article by Nature News: Fearful memories haunt mouse descendants
And the original research papers (pay-walled): Implications of memory modulation for post-traumatic stress and fear disorders by Ryan G Parsons and Kerry J Ressler in Nature Neuroscience 16, 146-153 (2013) doi:10.1038/nn.3296
