Hold on just a minute

The headline jumped out at me as I perused one of the several news feeds I check each day: "Taylor Swift is related to famed poet Emily Dickinson and now it all makes sense," proclaimed a CNN headline.

Ordinarily I wouldn't have cared a whit and moved on. I'm not a Swiftie or even a fan (then again I'm not exactly the target audience.) But these days she can hardly sneeze without some news outlet posting a breathless article about it. But with what I consider to be the inordinate amount  of publicity the woman receives and my delving into my family's past to learn more about history, I gave the article a read. 

A lot of questions popped up in my head. Who cares, was the first. Well obviously Swift fans, who've apparently made comparisons between the women. And I suspect they'd be excited because they would imagine a genetic link between the two women's perceived greatness, so of course their idol would have been fated to become their favorite songstress. Thus the headline.

Other questions: Sez who? Ancestry.com. Why did they even check on this? Haven't found that answer, other than it gives them a chance to piggyback on Swift's fame and gain attention for the service. What means did they use to discover this exciting [ho hum] news? That answer is a bit fuzzy. Most of the articles I perused before sitting down to write today don't give an answer, so they could have just traced the tree back using a computer and their database.

But some other articles indicated that Ancestry had traced the DNA back that far. Now, I'm not sure how they obtained Dickinson's DNA, or Swift's for that matter, but assuming they did actually have the pair's genetic info could they really have identified a DNA match between sixth cousins three times removed?

Simple math shows that the DNA would have been pretty diluted by then. Remember, the number cousin you are indicates how many generations you have to go back to find a common ancestor, while the removal part has to do with the difference in how far down the line you are from that ancestor. I know, it's confusing as confetti. 

If your and cousin's common ancestor is a fifth great-grandparent, you are sixth cousins. But if your common great-grandparent is your fifth great-grandparent and your cousin's is their 8th great-grandparent, you are 6th cousins three times removed. Still doesn't make sense? Think on it awhile. Or just find a chart on the Internet like I did. 

Now start doing the math. Your parents each gave you half their DNA. Their parents gave them each half their DNA, which means you have about 1/4 of each grandparent's DNA. Now go back another set of grands. How much of each person's DNA do you have? (If you did as well in math as I did, your head is beginning to swim.) 

In the end, according to 23andMe, by the time you get back to your fifth great-grands, on average you share 0.001 percent (that's 1/100,000) of your DNA in common with your sixth cousin. Factor in the extra DNA for the cousin who goes back farther to the common ancestor, and you're talking not much.

Despite that slim number, geneticists say that common DNA can still be detected that far back. That doesn't leave much material to form a gene that might, and I stress the word might, express a trait of poetic sensitivity.

Another thing to keep in mind is how many common ancestors we all share. In fact, some calculations show that if you go back to the beginning of recorded history you'll discover you are probably related, although quite distantly, to pretty much everyone on the planet. 

So, if you want to believe that genetics and genealogical relationship gave rise to Taylor Swift's putative song-writing abilities, go ahead, but know that any actual influence of Dickinson on Swift would more likely come from Swift studying the poet in a high-school English class, along with how much time the singer may have spent reading Dickinson's poetry since high school. 

Meantime, I think I'll check to see if Frost or Burns show up on my tree.