Ötzi tidbits

By Razib Khan | October 17, 2011 1:25 pm

The genome of Ötzi the Iceman is floating around somewhere, but for now we only have to go on what leaks out via the media. From National Geographic, Iceman Autopsy:

The genetic results add both information and intrigue. From his genes, we now know that the Iceman had brown hair and brown eyes and that he was probably lactose intolerant and thus could not digest milk—somewhat ironic, given theories that he was a shepherd. Not surprisingly, he is more related to people living in southern Europe today than to those in North Africa or the Middle East, with close connections to geographically isolated modern populations in Sardinia, Sicily, and the Iberian Peninsula. The DNA analysis also revealed several genetic variants that placed the Iceman at high risk for hardening of the arteries. (“If he hadn’t been shot,” Zink remarked, “he probably would have died of a heart attack or stroke in ten years.”) Perhaps most surprising, researchers found the genetic footprint of bacteria known as Borrelia burgdorferi in his DNA—making the Iceman the earliest known human infected by the bug that causes Lyme disease.

I’d guess that we’re talking about the HGDP samples from Sardina and the Basques, though those Basques were from the French side of the border. As you might know there are current models which posit that groups like the Basques and Sardinians are the descendants of Paleolithic Europeans who took up farming by and large through cultural adoption, and others which suggest that they’re mostly descendants of newcomers from the eastern Mediterranean. It doesn’t seem like Ötzi’s genome is going to resolve that, though we can at least peg a lower bound for when the last major demographic changes occurred in Sardinia. But, the fact that Ötzi is being compared to “isolated” populations in southwest Europe does tell us that there has been significant demographic turnover across this region over the past ~5,000 years, as Ötzi himself was from northern Italy. There is a northern Italian sample from Bergamo that Ötzi could have been compared to, and the fact that he wasn’t suggests that the modern people of the region are not easily explained as unaltered descendants of the relatives of Ötzi.

CATEGORIZED UNDER: Anthroplogy, Human Genomics
  • Charles Nydorf

    It is too bad there is no closer reference population as Bergamo is about 190 miles over rugged country from where ‘O’tzi was found.

  • Eurologist

    “the fact that Ötzi is being compared to “isolated” populations in southwest Europe does tell us that there has been significant demographic turnover across this region over the past ~5,000 years, as Ötzi himself was from northern Italy”

    It doesn’t have to be “turnover”. Agriculture allowed many distinct local populations in Europe to explode and to fix their differences. Subsequent diffusion over seven millennia has necessarily muddled the picture without requiring major migrations. People in Italy today of course have more Anatolian, Near-Eastern, Northern European, and Balkan admixture than over 5,000 years ago.

  • http://blogs.discovermagazine.com/gnxp Razib Khan

    #2, good point. i need to think on this….

  • Tom Bri

    Like to comment on the line about lactose intolerance. So, Otzi was lactose intolerant and that means he ‘couldn’t drink milk’. That is pretty dumb. Today, Japanese and Chinese, supposedly lactose intolerant, drink lots of milk. It doesn’t seem to harm them, or cause stomach upset. Sure, there are a few people who really are lactose intolerant , and really can’t drink milk.

    But in some place, some where, a group that was initially lactose intolerant started drinking milk even thought they were lactose intolerant. That gene for tolerance started spreading through a population that was mainly lactose intolerant, and they drank the milk in spite of it. So far I have not read of any study showing Otzi did or did not drink milk. The gene for lactose tolerance being present or absent doesn’t tell us anything on this question.

    Sorry Razib, a peeve of mine.

  • http://blogs.discovermagazine.com/gnxp Razib Khan

    1) cheese

    2) more ppl are lactose tolerant than have ‘lactose tolerance genes’ (cuz we’ve only discovered some of ‘em)

    3) you still get protein/fat value, just not sugar (lactose)

    4) gut flora can change and adapt

  • Sahar

    I’ve been to supermarkets in China. The statement that the Chinese “drink lots of milk” is absurd.

  • jb

    I’ve never seen any dairy products on the menu of a Chinese or Japanese restaurant, and it’s been my understanding that the Chinese in particular consider drinking the milk of a cow to be a disgusting thing that only foreigners do. (Think goat’s eyes at an Arab banquet).

    That said, the level of lactose tolerance among non-white Americans is typically reported to be considerably higher than what one would expect from talk about the genetics. For example, according to several sites:

    On average, 80% of Asian and Native Americans are lactose intolerant, 75% of African Americans, 51% of Hispanic Americans and 21% of Caucasian Americans.

    So 20% of Asian and Indigenous Americans have no trouble with milk? Really? Another site I looked at reported that in general African Americans who are technically lactose intolerant can still drink two eight ounce glasses of milk a day at meals without symptoms. I guess the real value of lactase persistence is that it lets you guzzle milk.

  • jb

    BTW, what about that saucer of milk for my cat?

  • pconroy

    @7,

    JB, you need to know the source of your comment, as in some places (UK) Asian=South Asian, and so many would be Lactase Persistent.

  • http://washparkprophet.blogspot.com ohwilleke

    “with close connections to geographically isolated modern populations in Sardinia, Sicily, and the Iberian Peninsula. ”

    This sounds a bit like saying that maize, wheat and soy are extremely similar to rice. Yes, they have something in common, but can you really say something has close connections to all of them?

    These populations aren’t extremely close to each other genetically, so it is a bit hard to know what is meant by this phrase. Sardinia, at least “remote” parts of it, show continuity back to the Neolithic and are close to the “Southern European” component that comes out of an Admixture analysis. Sicily has considerable Greek, Levantine and Southern Italian admixture. Even Iberian genetic isolates are perhaps 60% Sardinian and 40% other stuff in an Admixture analysis.

    Hg G2 you’d expect to see in the Caucasus, Tuscany, across the border in France and in early Neolithic LBK sites.

    In what sense do the teaser authors mean close?

  • http://www.buildinghistory.org/distantpast/ Jean M

    The comment on similarities with Sardinians etc was made in an interview by Dr Eduard Egarter Vigl who makes it clear that this is deduced from his Y-DNA haplogroup G2a4.

    http://www.youtube.com/watch?v=kRXiwWpmSbs

  • http://www.buildinghistory.org/distantpast/ Jean M

    In Iberia (including offshore islands) Y-DNA haplogroup G is highest in Ibiza and Portugal. Since so little testing has been done specifically of G2a4, I can’t say whereabouts in Iberia that might be found.

    G2a has appeared in a number of samples of ancient DNA from Neolithic Europe. It presumably spread with the Neolithic. I don’t think anyone has suggested that it appeared in Europe earlier than that.

  • Onur

    Jean, what about Sicily? In Sicily Y-DNA haplogroup G is not found more than in the average European country. So your inference that the comment on similarities with geographically isolated modern populations in Sardinia, Sicily and the Iberian Peninsula was deduced from Ötzi’s Y-DNA haplogroup does not seem to hold water.

  • Careless

    @9
    It’s pretty clearly Asian Americans.

  • Justin Giancola

    From someone who is lactose intolerant – and became so at 20, so I watched it decline from normal – once you reach the point where you make no lactase there really isn’t a whole lot of dairy you can eat other than in Very small doses that doesn’t cause problems. If you push it you end up with putrid burps and farts; usually sooner bowl movements of content you just ate – often in diaharrea; signs you aren’t digesting your food properly; it’s basically evacuation. I watched the amount of food that caused these extremes symptoms get smaller and smaller, and the need for lactase pills get more consistent and higher doses. Despite what people say about aged cheese; goat or sheep milk; active bacteria yogurts; once I presumably bottomed out of lactase production it’s basically pills all the time. I can do bites and sips basically.

  • jb

    On TV somewhere I saw that Japanese guy — the one who wins all the hot dog eating contests — chug a gallon of milk. He was racing a white guy who only had to drink 20 ounces, and he lost, but not by much. I really hope he knows about lactase pills!

    (BTW, he drank the milk after eating 32 hard boiled eggs in 1 minute. His stomach looked like a balloon!)

  • ADL

    Charles @9

    “It is too bad there is no closer reference population as Bergamo is about 190 miles over rugged country from where ‘O’tzi was found.”

    I was in the Ötzi museum in Bolzen a few months ago, and recall reading there that lots of things in Ötzi’s kit have archaeological correlates / apparent origins in the Lake Garda region. So he was quite a long way from home, but it’s a hundred miles up a wide, fertile, easily travelled (unless populated by hostile people) river valley from Lake Garda to where he was found, not much rough country involved until you reach the actual foot of the glacier.

    And .. there is a village on the west bank of Lake Garda – Limone – which was not accessible by road until the 1930s, whose population has well known genetic quirks as a result of long isolation, so should be well studied and available for comparison.

  • http://www.buildinghistory.org/distantpast/ Jean M

    >Jean, what about Sicily? In Sicily Y-DNA haplogroup G is not found more than in the average European country.
    It doesn’t have to be, as long as they found some G2a4 there. Look – I don’t have all the answers. But you can see for yourself what Dr Eduard Egarter Vigl said in his interview. He didn’t mention Sicily, only Sardinia. We currently don’t know if Sicily was an error by whoever wrote the blurb, or referred to something other than G2a4, or whether G2a4 was found in Sicily. A few more days patience and things may get clearer.

  • Onur

    Jean, I think in the National Geographic article they made the comment on genetic similarities based on the autosomal genetics rather than the haplogroups. So what Dr. Egarter Vigl said in the interview seems to be irrelevant to the comment on genetic similarities in the National Geographic article; they are likely talking about two different things: the former is about the Y-DNA haplogroup while the latter is about the autosomal genetics. But as you say, things may get clearer in a few days.

  • Eurologist

    Yes, y-DNA is a horrible indicator of autosomal relatedness.

    The example I like to give is that you can go into a village in east/central Germany and pick three men who look like clones and would test nearly as such autosomally. But, you have a good chance that one is R1a, one R1b, and one I2a2.

  • Ddraig werdd

    Justin Giancola @15
    I also became lactose intolerant in the early 20′. The transition was quite fast, going from being able to drink 1L of milk in one go (at least twice a week) to barely being able to drink a sip. What is somehow funny is that I first learned that lactose intolerance exist in college ( until then I thought that it was something only spoiled American kids have – I’m from a fairly big milk drinking culture). You may be able to you still get protein/fat value from milk but you will avoid it after the first negative experiences.
    About Sardinia there is something that I never quite managed to understand. How come it’s so isolated? The people are very genetically isolated, the native language is the most different Romance language ( the first to split up from Latin, some going as far as 1 century BC), for many centuries is was basically ignored by the outside world (like in the early middle ages). I know the interior is mountainous but it’s still a big island with mineral resources in the middle of a very traveled sea. So how did they manage to do it?

  • Alfredo

    The idea that South Europeans can’t drink raw milk is bollocks. I don’t have the “tolerance gene”, yet I drink raw milk daily, plus I put raw milk in everything: coffee, tea, cereal, mashed potatoes, pancakes, you name it. That milk is not fermented in any way. I find it mildly amusing when people try to convince me that I’m really intolerant but don’t realize it.

  • Tom Bri

    Sahar and JB, check out the ice cream selection. Besides, restaurants aren’t much of a data point. I can’t speak for Chinese supermarkets, but Japanese ones certainly have significant dairy sections. This is rather far afield form Otzi though. I taught a lesson on inventions, the text claimed that ice cream was invented in China. Can’t vouch for the accuracy of that textbook though, that was in the pre-internet days in Japan so cross-referencing was tough.

    Europeans began including dairy in the diet when a tiny fraction of the population was lactose tolerant. The sweeping phrase ‘couldn’t drink milk’ just bothered me. I guess the Nat Geographic isn’t a scientific publication, so precision of language isn’t a strong point.

  • http://blogs.discovermagazine.com/gnxp Razib Khan

    I guess the Nat Geographic isn’t a scientific publication, so precision of language isn’t a strong point.

    you have too high an opinion of scientific publications.

  • Justin Giancola

    21. yeah mine got really bad quick too! Adding to what you said about it being eat at you own risk, especially if you haven’t had the particulary dairy product before – without pills – I think if one kept the intake low to the point you aren’t getting indigestion/evacuation you might still get most of the fat and protein, but I question if having certain indigestables weakens quality of digestion overall.

    No one else in my family has what I have and my father is 100% Italian which leads to: Alfredo, I think razib made a good point in that there are likely other variants of lactose tolerance.

  • Onur

    JB, you need to know the source of your comment, as in some places (UK) Asian=South Asian, and so many would be Lactase Persistent.

    In the US the Asian category includes South Asians. This may explain some part of the percentage of lactose tolerant Asian Americans.

  • http://mengbomin.wordpress.com/ Meng Bomin

    @jb

    I’ve never seen any dairy products on the menu of a Chinese or Japanese restaurant, and it’s been my understanding that the Chinese in particular consider drinking the milk of a cow to be a disgusting thing that only foreigners do.

    Currently, milk with enzymes added is a product in China and I saw quite a bit of advertising from one of the main companies that sells it, 蒙牛 (Méng Niú, lit. “Mongolian Cow”), when I visited. As I’m not really Chinese (despite my online pseudonym) and haven’t lived in China long term and nor have I looked over food consumption statistics, I can’t tell you much more than that.

  • Justin Giancola

    It sounds to me like milk with lactase added, which you can buy here in US at most grocers as well.

  • Loog Garoo

    Worth noting that northern Italians are more inclined to lactose intolerance than southern Italians or Sicilians, and that Basques are practically free of it. http://en.wikipedia.org/wiki/Lactase_persistence#Distribution

  • Onur

    I think the published lactose intolerance proportions of Mediterranean and West Asian countries are greatly exaggerated and wrong (this is probably because many of the lactose tolerance genes haven’t been found yet). For instance, I, living in Turkey in my whole life, have never met someone in Turkey who I know is lactose intolerant. In Turkey milk drinking is greatly encouraged by doctors of medicine and by the governments for people of all ages because of the significant health benefits and I don’t see any talk about lactose intolerance. This is probably because very few people are lactose intolerant in Turkey. BTW, I drink several glasses of milk almost everyday and milk is one of my most favorite drinks (the others are beer and wine).

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About Razib Khan

I have degrees in biology and biochemistry, a passion for genetics, history, and philosophy, and shrimp is my favorite food. In relation to nationality I'm a American Northwesterner, in politics I'm a reactionary, and as for religion I have none (I'm an atheist). If you want to know more, see the links at http://www.razib.com

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