The oldest human to have his complete mitonchondrial (mtDNA) genome sequenced, a 5,000-year-old “Iceman” mummy known as Ötzi, does not appear to have any living relatives in Europe. The new genetic analysis reveals that Ötzi belonged to a previously unknown branch of human evolution. Said study coauthor Franco Rollo: “Apparently, this genetic group is no longer present…. We don’t know whether it is extinct or it has become extremely rare” [HealthDay News].
The researchers extracted DNA from Iceman’s rectum. They analyzed the genome of the cells’ energy-making structures, called mitochondria. “You only get mitochondrial DNA from your mother, and she gets it from her mother and so on, so it forms an unbroken link all the way back to the common maternal ancestor of all of us,” said researcher Martin Richards [LiveScience]. Earlier studies of fragments of Ötzi’s mtDNA had indicated that he was of the K1 lineage, which is further divided into three branches. But after comparing his complete mtDNA genome with that of 115 modern Europeans of K1 lineage, the researchers found three mutations that place Ötzi in a fourth, previously unknown, branch of K1.
It’s unclear what happened to this fourth branch of the K1 lineage between Ötzi’s time and ours. Ötzi’s ancient genetic comrades may have gotten swamped by other mitochondrial DNA lines as people congregated in increasingly larger settlements, the scientists suggest. Random changes in the mitochondrial DNA of Ötzi’s peers may have contributed to the absence of a match as well [Science News]. And some scientists are skeptical of the new findings, reported in Current Biology [subscription required]. “Because the Rollo team used intestinal material from the mummy, it is difficult to exclude the possibility that their unique mitochondrial DNA lineage is a result of contaminant DNA mixing in with Ötzi’s own genetic sequences,” [Science News] said evolutionary biologist Eske Willerslev.
Nevertheless, the new genetic study contributes to our already extensive knowledge of Ötzi’s life and death. Scientists believe he lived 5,350 to 5,150 years ago as a hunter-gather and died by an arrow in his back followed by a blow with a spiked club to the face…. In 2003, researchers reported that the mummy also appeared to have suffered from heart disease, arthritis, degenerative disc disease and a bit of frostbite [HealthDay News]. In 1991, German tourists stumbled upon his mummified corpse frozen in a glacier in the Italian Alps.
Related Content:
The Loom: The Mark of the Iceman
DISCOVER: Making a Modern Mummy
DISCOVER: The Mummies of Xinjiang
Image: flickr / Alkuin
October 30th, 2008 at 8:49 pm
I have had it pointed out to me that this is mased on the mtDNA only. That is only passed from mother to children rather than from the father.
While there may be an individual who does have Ötzi’s MOTHER’s mtDNA, certainly no one will have HIS mtDNA.
If there is anything that would be recognizeable DNA from Ötzi, it would be his Y Chromosome DNA or yDNA. He could have passed on the R1 haplogroup for most of Europe, but his mtDNA would neveer be passed on.
I think you should note that so-called science editors have been passing this story on without catching this.
October 31st, 2008 at 5:51 am
> While there may be an individual who does have Ötzi’s MOTHER’s mtDNA, certainly no one
> will have HIS mtDNA.
His mtDNA = His mother’s mtDNA. Thus by the transitive property, an individual who has his mother’s mtDNA will have his mtDNA.
October 31st, 2008 at 12:04 pm
Still; Ötzi?s mother may have only had sons. Or she may have only had him. Regardless, nobody knows Ötzi?s past, therefore if looking for relatives in the present it seems pointless to use mtDNA. If your looking for similar mtDNA now, you’re looking for relative’s of his mother…not Ötzi.
October 31st, 2008 at 1:55 pm
Very interesting. What is known about the haplogroup on his Y-chromosome? I.o.w. his paternal ancestry?
October 31st, 2008 at 7:49 pm
The relatives of his mother are not his? interesting.
If he was in a matrilineality system, only his maternal relatives considered as his kins.
November 1st, 2008 at 12:09 am
Surely Oetzi’s matrilineal cousins, many times removed, would be considered among his “kin”/”relatives”? If they were to exist, that is. Which it seems they don’t.
November 1st, 2008 at 1:46 am
The claim that “Ötzi, does not appear to have any living relatives in Europe” is nonsense. All the lack of Otzi’s mtDNA being found today suggests (but does not prove) is that there is no unbroken matrimonial line back to Otzi’s mother or her mother etc. Males do not pass on mtDNA so Otzi could have had a dozen children and thousands of descendants but they would not carry his mtDNA.
There could be many descendants of his mother, her mother etc, but only unbroken female lines will show mtDNA the same as Otzi’s.
Cheers
November 1st, 2008 at 1:42 pm
Does anybody know if Oetzi’s paternal halogroup is known?
November 1st, 2008 at 3:09 pm
Frans
As you can see that is my name also. what is your last name?
November 1st, 2008 at 3:55 pm
@Frans
Looks like the researchers are asking the same question! According to an article in The Scientist:
“Rollo’s team now plans to attempt the sequencing of Öetzi’s Y chromosome DNA, which is less abundant than mtDNA, but offers a counterpart to mtDNA, in that it is passed only through the paternal line.
‘It will be also very interesting to see whether the descendents of Öetzi indeed are all extinct,’ Rollo said. ‘[As far as we know], no one can claim to be the descendent of Öetzi but, who knows, perhaps in a lonely Alpine valley…’”
(http://www.the-scientist.com/templates/trackable/display/blog.jsp?type=blog&id=55145&o_url=blog/display/55145)
November 1st, 2008 at 7:21 pm
mtDNA as a tool to catalog human gene groups is better than Y-DNA, as the latter can only be used to catalog half of the human being.