About This Blog

Science Happenings with Rightler is a blog designed to share information about the cool stuff that is going on in the world of science. New discoveries, cosmic fluff, and all in between are grist for the mill. I will be giving my own take on the events as they happen.

Tuesday, February 28, 2012

Successful Ancient Nuclear DNA Sequencing

This is Oetzi.



For those of you who don't know who he is, he is the Iceman that was unearthed in the Alps in 1991.  He's also the world's oldest active murder case. 

Oetzi died in the Alps after being shot down with an arrow - 5,300 years ago.  One of the many interesting things about this case was that researchers were not only able to pull mDNA (mitochondrial DNA) and sequence it in 2008, but they have successfully isolated and sequenced nuclear DNA from Oetzi.

Here's some of the highlights of what they found.  1) He had blood type O.  2) He had a genetic predisposition to heart disease.  3) His ancestry shows more middle Eastern roots, which means that Oetzi was far far from home.  4) He was lactose intolerant.

Now the researchers said something about the lactose intolerance being linked to the development of agriculture.  I personally think that's bunk.  Many people of Middle Eastern, African and Asian descent are lactose intolerant.  It's related to the trade off we as a species get between synthesis of Vitamin D and protection from damaging UV rays.

It works like this.

People in the far northern regions, Germany, England, the Scandinavian Countries, etc. tend not to be lactose intolerant.  If you think about it it also goes with the pale and some would say pasty complexions found in those regions.  Because the sky is overcast and days tend to have weak sunlight (if any, if you live near the Arctic Circle in wintertime), people lost a lot of the melanin in their skin.   We can only synthesize vitamin D3 from sunlight but we can give it a boost by ingesting milk from other mammals, such as cows, sheep, horses, and goats.  So peoples in these regions lost melanin but retained the ability to process lactose into adulthood in order to stay alive.

People in more equatorial regions, on the other hand, have high and sometimes very high melanin content to their skin.  They've lost the ability to process lactose in adulthood as well.  Why?  Well because with more intense solar insolation they're getting all the vitamin D3 production they can handle.  The melanin is there to protect the body from the damage caused by UV radiation. 
 
Which by the way, folks, is what a "suntan" is.  Tanning is for leather, not for people.

So the whole development of agriculture at the time, while true, is just misleading.  But keep in mind this is a guy of middle Eastern descent found killed in the Alps and being studied by a lot of Nordic-based folks.  They would have a slightly skewed view.