Iceman DNA Is Unknown

October 31, 2008

Ötzi the Iceman, the 5300-year-old mummified "Iceman" discovered in 1991 in a melting glacier in the Ötztal Alps, is back in the news .

An international team of researchers led by Franco Rollo and Luca Ermini at the University of Camerino, Italy, has sequenced Öetzi's entire mitochondrial DNA (mtDNA) genome - which is passed down through the maternal line – and found that he belonged to a previously unknown branch of the human family tree.

The sequence represents "the oldest complete Homo sapiens mtDNA genome," according to the report published in Current Biology.

The study overturns previous research that suggested Öetzi has some living relatives, since he belonged to a genetic lineage known as K1 -- a line shared by about 8% of modern Europeans.

Using advanced genome-sequencing technologies, Rollo's team investigated the K1 haplogroup, which in turn, can be divided into three clusters.

Surprisingly, the Iceman's DNA did not fit any of the three known K1 clusters. On the contrary, Ötzi's DNA was found to belong to a novel branch of K1. The researchers named it "Ötzi's branch", or K1ö.

"This doesn't simply mean that Ötzi had some 'personal' mutations making him different from the others but that, in the past, there was a group of men and women sharing the same mitochondrial DNA. Apparently, this genetic group is no longer present. We don't know whether it is extinct or it has become extremely rare." Rollo said.

At least for the moment, he said, that means no one can claim to be the descendant of Ötzi.

Comments

[James Horn]

My understanding is that mitochondrial DNA is inherited solely through the female line. Thus the correct conclusion is that Otzi's mother has no known descendants. Otzi could have descendants, but they would carry the mitohondrial DNA of his children's mother. To say Otzi has known known descendants in a direct male line would require examination of his Y chromosome. To say he has no descendants, I would think to be almost impossible since the link could be his daughter, eliminating the Y chromosome as a tracker.

[Tearsthewingsoffangels]

mtDNA is probably mostly from the mother, but research suggests that things may be a bit more complex. The issue is a bit controversial, too, because the mechanism of paternal mtDNA transmission isn't understood, if it exists at all.

But poor Ötzi's descendants... considering he may have none, and he was apparently pursued into the mountains and fatally wounded by attackers, it's possible that he is witness to an early example of h. s. sapiens committing genocide...