Tuesday, January 12, 2016

5300 Year Old Iceman's Bacteria Genome Does Not Support Out Of India Theory

The genome of bacterium Helicobacter pylori found in  the stomach of the 5300 year old European mummy named the "Iceman" shows close similarity with Helicobacter pylori strains found in the gut of north Indians. This finding published in Science has been used as evidence to support the Out of India theory, which proposes that the Aryans and the Indo-European language family originated in India. One branch of it spread into Europe, diverging into various IE languages, while the branch which remained in India became the common  ancestor of Iranian and Sanskrit. A later migration into Iran founded the Iranian branch of the IE family.

Here is a tweet by Subhash Kak, one of the proponents of the Out of India theory.

He and others who use this finding of the bacterial genome to support this scenario are wrong.

Here's why.

Their scenario requires the European strain of Helicobacter pylori to have been derived from the Indian strain. That means people from India migrated  into Europe in the Neolithic-Early Bronze Age around five to six thousand years ago carrying with them the Indian bacterial strain which then evolved into the European variety found in the Iceman. This interpretation is demonstrably wrong. The analysis of the bacterial genomes clearly shows that the Indian strain shares ancestry with the European strain

" The resulting linked co-ancestry matrix (Fig. 4) showed that the ancient H. pylori genome shares high levels of ancestry with Indian hpAsia2 strains (Fig. 4, green boxes), but even higher co-ancestry with most European hpEurope strains".....

... "Furthermore, our co-ancestry results indicate that the Iceman’s strain belonged to a prehistoric European branch of hpAsia2 that is different from the modern hpAsia2 population from northern India".

In plain English what this mean is that the European strain has not evolved directly from the Indian strain.  Rather, the European strain and the Indian strain share an Asian common ancestor. This is clearly seen in the phylogeny (evolutionary relationship) presented in the supplementary materials of the  paper (page 50 of 88). See the image below.

Source: Supplementary Materials Maixner et al. 2016

The red arrow points to the common ancestor of the Iceman and Indian strains. The Iceman's strain and the Indian strain are sister lineages. The European strain is not derived from the Indian strain. The most sensible explanation of this finding is that from a common Asian source in the Anatolian / Near East region this bacteria spread into Europe and into India with the Neolithic expansion of farmers. It then diverged into the respective strains seen in the Iceman and in extant Indians. In Europe, this Asian derived strain then mixed with an African variety due to a migration in more recent times.

No evidence can be  found for a bronze age Out of India migration of people and languages from this study of the Iceman's bacterial genome.


  1. Gee.... the ice man's Y-chromosome haplogroups is G which originated probably in Iraq/Iran and migrated both east and west and his mtDNA haplogroups is K which originated in eastern Europe. Seems to me that study of his gut bacteria has very little to say about origins. Except to point out as you do that there was likely a common Asian (western Asian) origin to that E. coli which arose in India and the ice man. Talk about jumping to unfounded conclusions, Kak sure did.

  2. Lynn- exactly...no India specific human genetic markers are present in the Iceman. But such mere details don't bother OIT proponents :)

  3. Why do people wish to somehow by hook or crook try to prove humans originated in India, or at least civilisation originated in India? Even if all Europeans originated in India, how can we take credit for it? What is our contribution to it- the contribution of proponents of this theory? The same applies for the excessive jingoism about 'Vedic science'. Even if half of what they claim is true, then we should be ashamed, not proud that inspite of having such a legacy, we have ended up at the bottom of everything- it is not something to be proud of that we lost the edge that we claim we had, like a golfer with a single digit handicap losing to a 20 handicapper.... well, we can always blame Queen Victoria.

  4. You are on point again L :)

    It is jingoism at its silliest considering our fall from grace!