Epigenetics, DNA, And How Did I know That?

     One of my earliest childhood memories is of my mother laughing when she served me a salad with dinner.  Why did that amuse her?  Because invariably the first thing I would do is remove the onions from the salad and place them in my mashed potatoes with a large dollop of butter.  At times some of the lettuce found its way in as well.  It seemed the most natural thing in the world to me, onions belonged in mashed potatoes didn't they?  While we consumed large quantities of mashed potatoes in my family, I had never seen anyone else do this, in fact my parents both found it quite odd, but I was very fond of it.

     Fast forward to my young adulthood.  While browsing Irish recipes for a traditional meal to prepare on St. Patrick's Day I came across a recipe for something called Champ.  The ingredients were potatoes, butter, milk and...scallions or onions!  My mind went back to those family dinners and my childhood version of Champ.  Would it be fanciful to think it could be genetic memory?  I admit it's a trivial thing, but still, I wondered.  I actually looked up the history of Champ, finding it had been eaten in Ireland as early as the 1700's.

     The whole idea of inherited memory is a controversial subject with some scientists dismissing it outright while others believe there is a basis to consider it.  Perhaps memory isn't even the right word to use, it's more of a feeling.  Experiments done with mice have shown that rodents who were trained to avoid a certain scent passed that aversion on to their offspring.  In another study, mice trained to navigate a certain maze were also able to pass that ability on.  That being the case, why couldn't pleasant sensations, like that generated by eating delicious potatoes and onions, pass to following generations?  The famous psychologist Carl Jung thought they could be.  Researchers today theorize environmental influences, such as food, can leave chemical marks on genes that do not alter their sequence, but do modify their activity and could indeed be passed down. This emerging field is called epigenetics.

     Genetics and DNA is a fascinating subject to me, as well as a bit confusing.  My father's DNA changes every time Ancestry does an update, though I understand the reasons for that.  At present his ethnicity is 80 percent Irish and 20 percent Scottish at Ancestry, while FTDA puts it at 72 percent Irish and 28 percent Scandinavian. Scandinavian?  Must be those Vikings.  His maternal great-grandparents were all born in Ireland.  On his father's side, all but two were born in Ireland.  One great-grandfather was born in Warwickshire, England where his Warner family had resided for centuries.  That man's wife was born in America to family that came from Lincolnshire, England in the 18th century.  So it follows, three of his four grandparents were Irish and one was English.  It further follows, his mother was Irish and his father half Irish and half English. Yet neither testing site mentions a smidgen of English DNA.  I guess that's possible if Dad's only genetic inheritance from his father was his Irish DNA, but still somewhat surprising.

     I wish I understood this all better.  I think I need a class or two. In the meantime, I'll just keep enjoying my Champ and believing my affinity for it was a gift from the grands.