August 16, 2012

Ötzi was much more Neanderthal than usual

Paleoanthropologist John Hawks mentions today in his blog that he and colleagues have found that the famous Neolithic mummy Ötzi's genome is much more Neanderthal than modern day Europeans and Asians. Almost double in fact:




So if the average modern European is (est.) 2.4% Neanderthal, Ötzi could well be some 4.5-4.8%. What is less clear is whether this means a Paleolithic residue of excess Neandethal blood or a Neolithic arrival of excess Neanderthal blood from West Asia, if this can be extrapolated to all Europe or some wider region or was instead restricted to Italy (which stood apart from the main late Upper Paleolithic currents) or even a peculiarity of Ötzi's ethnic group (La Lagozza culture, part of the wider Cardium-Pottery cultural phenomenon). 

In December I detected anomalous high FST distances in an autosomal component of some Alpine populations, specifically a component important in the 1000 Genomes' Slovene sample (22%) but not in any other West Eurasian population I could observe (values of <2%). As I said back in the day, it may be some sort of error, but I wouldn't mind if the matter was further researched. If not an error, it could be a residual component from the "Out of Africa" period, judging from the FST value. Take all this with lots of salt, of course, just trying to explore possible explanations. 

5 comments:

  1. It may be interesting to include other early neolithic people, like the La Braña specimens.

    I can't see why would Otzi be genetically special: judging from his DNA, he's closest to Sardinians, who are average on neanderthal ancestry.

    I can't see either whether he's more "neolithic" or "paleolithic" than present-day people. It makes no sense at all, does this may mean that most of Europe and/or W. Eurasia was brutally replaced in the last 5.000 years? But by whom, and where did they come from? Otherwise, maybe neanderthal DNA has mysteriouly diminished over time, withouth this implying any replacement? There must be some explanation.



    ReplyDelete
    Replies
    1. Very true. People who use Twitter (I do not) might want to suggest John Hawks to extend their study this way. La Braña and several Swedish Neolithic samples are known to some extent and should also be comparable, providing counterpoints for the study of the Europeans of that period in this aspect.

      "I can't see why would Otzi be genetically special"...

      Me neither on first sight, specially as we do not know how the other samples from the period compare in this aspect. But would the others be "normal" in Neadnerthal ancestry, I'd suggest to explore the "Caucasus" component (per Dienekes' methodology) in the Ötzi genome, which is unusually high (>20%) and suggest a more marked "Neolithic" input.

      But first we'd need to know what's up with the rest. It can be a now erased very local deviation, a now highly eroded Neolithic input or a pre-Neolithic situation, also very eroded now.

      Delete
  2. This is interesting, but similar to the two papers below, there are so many possible explanations for this finding, that it provokes nothing beyond a desire for more data

    ReplyDelete
  3. Maju,

    There was also that Europe-wide map of autosomal diversity which showed the Slovenian (or Slovakian?) sample situated way South of where it ought to appear, closer to Sicily or Cyprus - do you remember that?

    ReplyDelete

Please, be reasonably respectful when making comments. I do not tolerate in particular sexism, racism nor homophobia. Personal attacks, manipulation and trolling are also very much unwelcome here.The author reserves the right to delete any abusive comment.

Preliminary comment moderation is... ON (sorry, too many trolls).