“At the heart of this new field is a simple but contentious idea – that genes have a ‘memory’. That the lives of your grandparents — the air they breathed, the food they ate, even the things they saw — can directly affect you, decades later, despite your never experiencing these things yourself. And that what you do in your lifetime could in turn affect your grandchildren.”
http://www.bbc.co.uk/sn/tvradio/programmes/horizon/ghostgenes.shtml