Showing posts with label DNA. Show all posts
Showing posts with label DNA. Show all posts

Friday, November 21, 2008

DNA as an Historical Tool--Copernicus's Remains Identified


It was widely reported this morning that the remains of Nicholas Copernicus have been identified by DNA testing. Polish and Swedish researchers accomplished the feat by comparing DNA from remains long-suspected to be Copernicus's, but buried in an unmarked grave, with remains of hair found in one of Copernicus's books.

Copernicus, of course, was the 16th century astronomer generally credited with being the first to realize that the earth revolves around the sun, rather than vice versa.

My favorite aspect of the story is that the researchers have also published a reconstruction of Copernicus's face, seen here.

I was curious how they could have come up with this level of detail simply with DNA. If you are as well, it appears that the explanation is "They can't." The explanation of why they are confident that the reconstruction is accurate is so hysterically inane as to deserve quotation in full. Here is Polish archaeologist Jerzy Gassowki on the subject:
[The reconstruction] bears striking resemblance to existing portraits of Copernicus. The reconstruction shows a broken nose and other features that resemble a self-portrait of Copernicus, and the skull bears a cut mark above the left eye that corresponds with a scar shown in the painting. Moreover, the skull belonged to a man aged around 70 -- Copernicus's age when he died in 1543.

In other words, we matched the DNA, then we went and looked at the skull and a bunch of old pictures of the guy, and created a face that fit both, and looks old to boot! Modern advances in science are indeed extraordinary.

Greg Priest

Sunday, October 5, 2008

Genetics provide keys to missing evolutionary links.

DNA analysis identifies an individual's unique genetic pattern, called a genotype. This information can be compared with other genotypes for purposes of identification. mtDNA is the DNA from the maternal side which can trace the evolution of the H. sapien from which both modern man and neanderthals are derived.

In the below articles geneticists have used mtDNA to confirm that modern man and neanderthal man are not related although they both roamed some of the same territories during the same period. As I read Janet Browne's Darwin's Origin of Species I was struck by how the genetic sciences continue to reveal evidence of adaptation (or the lack thereof), confirm natural selection, fill in missing links and present physical evidence.

http://www.youtube.com/watch?v=rfBmFx-g13Q

http://www.pbs.org/wgbh/nova/neanderthals/mtdna.html

http://news.nationalgeographic.com/news/2008/09/080917-neanderthal-photo.html

-Pamela Alexander-Beutler