Memories in Our Genes?

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Could our ancestors’ experiences leave a mark on our DNA?

What makes people different from each other?  What made our ancestors different from each other?  Why are some people happy and optimistic, able to weather any storm with great inner fortitude?  And what makes some people anxious and pessimistic, susceptible to depression?   No doubt our ancestors displayed these same variations in character.    Are those character or personality traits random or could it be that we carry in our genes some kind of ‘genetic memory’ of our ancestors’ experiences?

I’ve long been fascinated with the idea that we may not only have Grandma’s hands but that maybe we also have Grandma’s predisposition towards anxiety.   Could our ancestors’ experiences, whether traumatic or favorable, leave a mark on our DNA?  Scientists studying the field of what is now called ‘Behavioral Epigenetics’ think so.

Animal studies seem to support the idea that the environment can affect an individual’s genetics, which can in turn be passed on.  An Emory University School of Medicine study in 2013 showed that mice trained to fear the smell of cherry blossoms would, when bred, pass along that fear to their children and grandchildren.  Those mice descendants had never been exposed to the smell of cherry blossoms before but exhibited a negative reaction to it.  Not only was their behavior affected but the brain showed a physical change in the area that processes odor and a marker was found on the odor gene of the mouse DNA.

According to an article written for Discover Magazine by Dan Hurley. “Jews whose great-grandparents were chased from their Russian shtetls; Chinese whose grandparents lived through the ravages of the Cultural Revolution; young immigrants from Africa whose parents survived massacres; adults of every ethnicity who grew up with alcoholic or abusive parents — all carry with them more than just memories”.[1]

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Our ancestors’ experiences may affect us more than we realize. (Photo in public domain)

It’s highly unlikely that we will suddenly remember Great Granddad’s wedding day but the idea that perhaps our genomes carry some type of genetic marker from an ancestor’s experience doesn’t seem too far out of the realm of possibility to me.   The results of the research currently occurring may even help to explain why people suffer from seemingly irrational phobias – it may be based on the inherited experiences of their ancestors.  Thanks then to whichever of my ancestors passed along a decidedly unreasonable fear of moths that I have had since I was a child!

[1] Hurley, Dan. “May 2013.” Discover Magazine. May 2013. Web. 01 Mar. 2017. <http://discovermagazine.com/2013/may/13-grandmas-experiences-leave-epigenetic-mark-on-your-genes&gt;.