It's truly fantastic to hear that scientists have used a specimen of permafrost-preserved hair to sequence the genome of a male, known henceforth as Inuk, who lived in Greenland some 4,000 years ago.
This feat was performed under the direction of two Danish geneticists, Morten Rasmussen and Eske Willerslev, and their results were confirmed by laboratories throughout the planet... including a DNA laboratory at Murdoch University in Perth and an Australian police laboratory in Canberra.
The basic article concerning this achievement, entitled Ancient human genome sequence of an extinct Palaeo-Eskimo, appeared in the journal Nature. [Click the banner to access the article.]
Inuk's paternal haplogroup is designated as Q1a, which characterizes peoples who migrated from Siberia into the New World some 5,500 years ago. He belonged to a cultural group called the Saqqaq. Funnily, this means that Inuk does not belong to the same family as modern Inuit populations. To obtain their spectacular results, the researchers had to identify over a third of a million SNPs (single-nucleotide polymorphisms, called "snips"). The most amazing aspect of these findings is that Inuk's genome provides the researchers with a lot of interesting facts about this man's physical features:
— His blood type was A+.
— He probably had brown eyes.
— His skin and hair were probably rather dark. Besides, he would have normally become bald at an early age.
— He probably had front teeth of a form designated as "shovel-graded".
— His earwax was probably of a dry kind, like that of Asians and Native Americans (as distinct from the wet earwax of other ethnic groups).
It's amusing to learn that, since none of the institutions involved in this project employ Saqqaq descendants, the chances of errors due to DNA contamination from laboratory assistants were practically zero.
In my recent article entitled Nativity rites [display], I made a plea in favor of the systematic DNA-testing of babies. My old friend Odile phoned me the next day to tell me that she thought I had "blown a fuse"... which suggests that many people still regard DNA-testing as a weird operation. No, I persist and sign this idea— which is not at all crazy—of nativity rites of a new kind, based upon a DNA record for the newborn child. When we observe the fascinating facts that can be gleaned from a DNA specimen that dates from four millennia ago, it becomes obvious that we should encourage the generalized registration of such fabulous individual "blueprints".
What?What?What?
ReplyDeleteDifferent races have different ear wax?
I'd never heard such a thing?
I thought you were pulling our legs!
I had to google it.
Anthropologists use it to track migratory patterns?!?
Am I the last person to know about this?
The story of Inuk (and his ear wax, among other things) has been told many times over the last couple of weeks, and it will surely remain, for some time, the most spectacular case of DNA analysis applied to an ancient specimen of the modern creature (us present-day humans) known as Homo sapiens sapiens (where the repetition of the term sapiens is deliberate, for reasons that are explained in elementary textbooks on human paleontology). The most informative account of Inuk's tale is the original Nature article, but there have been many more popular presentations... and they all, of course, mention the earwax anecdote.
ReplyDeleteI must make a tiny but fundamental correction to your comment, in which you speak of "different races". Concerning Inuk and every single human being who has lived on Earth for the last 200 millennia, there have never been any "different races". Inuk, like me and countless other human beings, dead and alive, belonged to the unique race named Homo sapiens sapiens. Now, within that single race, there are family categories known as haplogroups, which have been established over the last couple of decades through vast DNA-testing projects in the exciting new domain of population genetics. The Y-chromosome family tree of mankind, called a phylogenetic chart, uses the letters A to T to designates these haplogroups. As I pointed out in my blog article, Y-chromosome analysis indicates that Inuk belongs to the Q1a haplogroup. As for me, I happen to be a relatively close "tribal neighbor" (the first term in "phylogenetic" come from the Greek phulos for "tribe") of the archaic Eskimo, since my haplogroup belongs to the next letter category, R1b1b2a1b5 (which is a wet-earwax haplogroup).
I should insist upon the fact that the earwax thing is a relatively unimportant phenotypic trait. But it happens to be a quite sound and useful trait. Far more important, in the modern world, is the examination of genotypes that are capable of revealing health problems. I probably don't need to tell you that many young parents throughout the world have called upon this kind of DNA-based medical test when deciding to have children.
The best way of becoming familiar with this absolutely fabulous domain of human discovery is to contact the US organization Family Tree DNA and join up with the hundreds of thousands of individuals who have had their DNA tested. For ages, through my Antipodes blog and elsewhere, I've been trying to persuade relatives and friends to get involved personally in this huge discovery adventure (promoted also by National Geographic and IBM). Admittedly, you need to spend a bit of time learning the basic technology and jargon, but it's not too difficult. As I said in my recent article entitled Nativity rites, I believe it would be an intellectual act to offer every newborn baby a permanent declaration of his/her genetic heritage, because it is by far the most priceless treasure that any human being possesses.
Needless to say, the vast subject of human biology is too profound to be discussed seriously within the context of a blog... but I hope constantly that my mention of this domain might lead people (particularly my "genetic cousins" in Australia and the Old World who are participating in my genealogical research) to become aware of this quest for knowledge.
The adjective describing the act of presenting babies with a record of their DNA (instead of baptizing them or mutilating the penises of little boys) should read "intelligent", not "intellectual" (slip of the pen).
ReplyDelete