Neanderthal DNA

neanderthal


23andMe.com, the online DNA-analysis company, came back to us with information on our Neanderthal descent. Mine is 2.6 percent; Partner’s is 2.8 percent.

There’s been lots of disagreement about our Neanderthal cousins. They were shorter than us and almost certainly stronger, with heavy brow ridges, and maybe larger brains. But Homo sapiens sapiens somehow swamped them, and now they’re gone.

Except that our H. sapiens sapiens ancestors (evidently) interbred with them.

The Neanderthal genome has been recovered from fossils and compared to the modern human genome. Result: most people of European and Asian descent have at least one percent Neanderthal DNA; some have as much as four percent. (People of pure African descent have none at all, or nearly none.)

It’s fun to think about our caveman ancestry. I even bought the t-shirts that 23andMe offered, with a cute Fred Flintstone-type caveman depicted on them, and Partner’s and my respective percentages printed alongside.

But maybe I’m proud of my Homo sapiens sapiens ancestry too. Maybe I’m proud of all my ancestors, unicellular and multicellular, mammalian and primate. They all had one thing in common: they reproduced, and their offspring lived long enough to reproduce also.

I have not had children in my lifetime, and almost certainly never will. My genome (such as it is) will be lost. But hopefully my nephews and nieces will manage to carry on the odd and unique messages in our family DNA.

I feel like a caveman, thinking about a future I won’t share.

But maybe – just maybe – some fragment of my family inheritance will survive in that future.

Here’s hoping.


The ACHOO gene

photic sneeze


Years ago, my mother used to hang her laundry out on the line in our backyard to dry. She wore sunglasses, even in the weak Northwest sunlight, because the sunlight made her sneeze.

It makes me sneeze too. Not every time, but often.

This is the “photic sneeze reflex.” It has a couple of other names, including (seriously) the Autosomal-dominant Compelling Helio-Ophthalmic Outburst reflex (ACHOO!), as well as the Peroutka Sneeze Reflex.

Why? I’ve read many explanations over the years. First, it was said that blue-eyed people were prone to this, because (somehow) our pale irises let more light into the eyeball, which was somehow irritating. Well, I’m blue-eyed, so fine. But my mother was brown-eyed. So let’s try again.

How about this one? When you look into bright light, your pupils contract very suddenly. The muscles which control this don’t usually work that fast or that hard, and they twitch. This feels like a tickle inside your nose, and – achoo!

This theory doesn’t hold up experimentally either, apparently.

The reflex appears to be genetic. 23andMe, the genetic-assay project which both Partner and I joined recently, tests for this, and – guess what? – I have the gene.

So it’s genetic. So what?

What else can you think of that’s genetic and caused by sudden exposure to light?

How about epilepsy?

(And this, brothers and sisters, is what genetic research is all about.)

(And – you see? – I’m a mutant after all.)


23andMe.com

23 and me


A year or more ago, Partner and I bought into a very bad gene-testing thing, which told us (ridiculously) that we were both of Iraqi origin. It turned out that the test was the same one that the FBI uses: it’s very good for identification, but it doesn’t really give you any information on heritage, or disease, or anything else.

Well, okay. I only paid about $40 for testing for the two of us, so I got what I paid for.

Now: behold! The much more reputable 23andMe.com is offering its much more comprehensive testing for only $99 per person! They give you info on your heritage, and your Neanderthal inheritance, and your likelihood to develop genetic conditions. They are very thorough.

For Xmas, I bought lifetime memberships for both myself and Partner.

Well, my results have come in. I can summarize them as follows:

1)    I have DNA.

2)    It appears to be human.

I have no genetic predisposition toward either Alzheimer’s disease or Parkinson’s disease. This lowers my chances of contracting either, although nothing is certain.

I have a heightened susceptibility toward several cancers, including melanoma, prostate cancer, and especially stomach cancer. (There’s lots of cancer in my family, but none of these three. I am fascinated by this. There are risk factors that I can avoid for all three, and I need to think about this.)

I am genetically sensitive to the medication Coumadin / Warfarin, which is a commonly-prescribed blood thinner, which means that a regular dose would be too much for me, and I should be prescribed a lower dose. (I should tell my doctor. But will he listen, or just smile and pretend to listen?)

I have a three-times heightened likelihood to develop an especially nasty kind of glaucoma. Uh-oh. I’ve always had vision problems.

I am slightly taste-blind, especially toward bitter tastes. This is exactly correct. I love bitter flavors, and this is probably because I can’t taste them very well. People with “supertaste” can’t stand bitter tastes; they spit them out immediately.

I probably have blue eyes, moderately straight hair with a wave, B-positive blood, and I do not tend toward male pattern baldness. Correct, correct, correct, and correct.

They’ve churned up my national heritage too. I have a lot of northern European ancestry (my mitochondrial DNA hails from Doggerland, a place submerged beneath the North Sea, halfway between England and the Netherlands). I have a drop of Italian (not much), and lots of crazy eastern European (Czech, Hungarian, Russian, “Balkan”), and a surprising amount of Scandinavian.

Also I share tiny bits of other lineages. A tenth of a percent of something that might be Ashkenazi Jewish. A tenth of a percent of something that might be sub-Saharan African.

Gandhari says in the Mahabharata: Origins are obscure.

But sometimes we learn things about our origins, and they become a little clearer.


 

Genetic origins

Oetzi


Partner and I are doing one of those DNA analysis things.  Some of them give you health information, and possible relationships with other test subjects; this one is a bargain-basement test (basically the same test the FBI uses to identify murder suspects) which checks and identifies thirteen genes.  It will then compare our genome (or, rather, those thirteen bits of it) to an international database, and tell us our (possible) countries of genetic origin.

 

 

Nothing for sure, of course; it’s too generic for that.  But the results will be interesting.  Origins are mysterious; maybe even a rough idea would be nice.

 

 

The modern USA was founded by lots of Europeans who basically swamped the original population, wiped them out with war and disease, and replaced them.  Australia followed the same pattern.

 

 

But in much of the rest of the world, this was not the case.

 

 

Africa was conquered by Europeans, but never swamped.  India, ditto.   Siberia, ditto.  South America – well, parts of it, anyway. 

 

 

And then there’s Europe.

 

 

Back in 1903, a man’s skeleton was found in Cheddar Gorge in southwest England.  It was dated to approximately 7000 BCE.  Cheddar Man’s mitochondrial DNA was sequenced in the 1990s, and then – just for laughs – it was compared to the mitochondrial DNA of people living in the neighborhood.

 

 

There were found to be two exact matches, and one almost-exact match.

 

 

Nine thousand years later, Cheddar Man still had some relatives in the neighborhood.

 

 

The Maghreb (which includes all of North Africa west of Egypt) is considered to be part of the “Arab world.” Oh, really?  It was, and is, the Berber world.  It absorbed its invaders: the Arabs, the Romans, the Visigoths, the French, the Italians, the Spanish. 

 

 

And best of all:

 

 

Apollonia, about to leave for her most recent European trip, was excitedly talking about visiting her family up on the Alpine heights of northern Italy, and the history of her family’s village, and its pre-Roman roots.  Excitedly she Googled a reconstructed picture of Oetzi the Iceman, the 5300-year-old mummy found near the Austrian-Italian border, not far from her family’s hometown.  “Look at him!” she crowed.  “It’s my uncle Ettore!  It’s my nonno!”

 

 

And, strangely enough (though I didn’t say this to Apollonia), Oetzi looks a little bit like my grandma.

 

 

Origins are mysterious

 

 

But let’s wait for the DNA results before we say more.


 

 

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