Diabetes risk gene 'from Neanderthals'

[Omaha Steve]

Source: BBC

By Paul Rincon

A gene variant that seems to increase the risk of diabetes in Latin Americans appears to have been inherited from Neanderthals, a study suggests.

We now know that modern humans interbred with a population of Neanderthals shortly after leaving Africa 60,000-70,000 years ago.

This means that Neanderthal genes are now scattered across the genomes of all non-Africans living today.

Details of the study appear in the journal Nature.

FULL story at link.


Read more: http://www.bbc.co.uk/news/science-environment-25506198

---

Neanderthals interbred with humans and their genes are scattered among us today

[octoberlib]

1. Interesting. nt

[BlueStreak]

2. The human genome project is really paying dividends

The amount of knowledge gained in the last 2 years about our ancestors if staggering. Genetic studies have disproved a great deal of what was previously believed about these ancestors -- where and when they lived.

It really is an exciting time in this field.

[starroute]

3. But if we got it from Neanderthal, why is it as rare in Europe as in Africa?

The only explanation I can think of is that modern humans interbred with different groups of Neanderthals in different places.

The ancestors of Native Americans, who came from somewhere in Siberia, might have interbred with the Neanderthals whose remains were (surprisingly) found in the same Siberian cave as the Denisovans. That could explain why the gene is 50% in Native Americans and 20% in East Asians.

But the ancestors of Europeans might have interbred with Neanderthals only in the Middle East or Europe -- and that bunch might not have had the diabetes gene.

If this is so, it could also explain why some studies conclude that Europeans have a higher percentage of Neanderthal DNA than Asians and others that they have less.

All very interesting.

[bhikkhu]

14. different groups in different places - exactly right

at least as far as the most modern theories go.



note the Denisovan component in the Asian branch.

[DhhD]

16. Early hominids in Britain and other parts of Europe 800,000 years ago and between Ice Ages.

http://goddesschess.blogspot.com/2010/07/early-hominids-in-britain-more-than.html

http://www.amnh.org/exhibitions/past-exhibitions/human-origins/the-history-of-human-evolution/the-first-europeans

http://news.nationalgeographic.com/news/2007/07/070705-antarctica-ice.html

[bhikkhu]

18. In the old view of human ancestry, all those lines went extinct

...where you had a world one or two hundred thousand years ago with a variety of hominids living everywhere in Africa and Eurasia. But every one of those groups (outside of Africa) went extinct for one reason or other, replaced by a single group that migrated from Southern Africa. Which is why there is a great deal of genetic diversity within African populations, but very little variance outside of Africa.

Of course, modern genetic research shows that when our ancestors migrated out of Africa they did intermarry or mix one way or another, to a limited extent, with at least three other distinct populations. The other lines were certainly overwhelmed, but in a small way absorbed rather than extinct.

[starroute]

17. It also suggests that sex among branches of the family tree was common

Many of the articles on our interbreeding with Neanderthals and Denisovans have suggested that the relatively low percents of their DNA in our own genome mean there wasn't all that much interspecies hanky-panky going on -- because, after all, who would want to bring an icky Neanderthal home to mother?

But it's starting to seem more like we and our close cousins got it on wherever and whenever we could -- but that we were far enough apart genetically that those matings only occasionally produced viable offspring.

The world was a very different place in those days, but it could teach all of us some lessons in tolerance and inclusivity.

[awoke_in_2003]

21. She's a very icky girl...

the kind you don't bring home to momma. She's Neanderthal, Neanderthal, she's super icky.


Now I have a certain Rick James song stuck in my head.

[arcane1]

26. Dammit!

[Igel]

23. Rather than a "deep historical" explanation I'd go for a more recent one.

Diabetes wasn't are among Native Americans 600 years ago.

Their diet wasn't that rich in sugars and starches. They had to be more active. Their diet and activity levels kept their weight down and diabetes in check.

There are substances in some native plants, at least in N. Mexico and the American SW, that help inhibit wide swings in blood sugar. They help limit diabetes. They were common in indigenous pre-Columbian diets and in a variety of "poor" diets.

While this was going on in prehistory, the Europeans got wheat and had all sorts of starches in their diets. They could be plumper and ate far more more pure kinds of starches and sugars. There was probably a diabetes mortality problem over several thousand years that reduced the prevalence of the gene. Humans are as subject to natural selection as any other critter and have a range of adaptations to prove it.

Currently European-Americans have a high diabetes rate because our diets have become richer in carbs and we're even more sedentary. It's unclear that this would affect the gene pool, though--it mostly affects those who have passed the age when they'd procreate.

In Native Americans, though, who missed that first wave of natural selection, it's an outrageously serious problem. It's just vanishingly rare to see the ethnic distribution of diabetes even mentioned in the press. The press likes absolutes, yes/no kinds of contrasts as well as any contrast that casts some sort of negative light on a "victim" group or anything that could be viewed as a genetic difference that is in any way race- or ethnicity-based. For a long time the ethnic distribution of lactose intolerance was all but verboten in the MSM.

[starroute]

25. East Asians have been eating rice much longer than Europeans have been eating wheat

And the article says the gene has a 20% prevalence among them.

(On edit) Also, corn was domesticated in Mexico as early as 8000 BC.

I absolutely agree with you that the neglect of the diabetes problem among Native Americans is outrageous -- but I don't agree that attributing it to a gene is somehow blaming it on the victims. I think it's just that Euro-Americans are self-centered and take themselves as the norm and are pretty oblivious to anything outside their own preconceptions.

A more useful question might be what the diabetes gene is good for. It seems that most of what we picked up from the Neanderthals was useful in some way, such as immunity to certain diseases. So what advantage was conferred by this gene? Did it help us thrive when we moved out of the tropics and were forced to live on a high-protein, low-carb diet?

[Coyotl]

4. Genetically, there are no "Latin Americans" just Native Americans and Europeans gene pools

combining after 1492 in Latin America.

[Spider Jerusalem]

8. Not actually true

Genetically, distinct native American populations can be distinguished by the prevalence of particular combinations of genetic markers, as can distinct European populations, distinct African populations, and so on. This is because of a few factors: the "founder effect" (a smaller initial migrant population in a given area has lower genetic diversity and passes on only a subset of the genes found in the parent population; Ashkenazi Jews and the Amish are examples...the genetic disorders found in both populations are the result of the founder effect), and genetic drift (changes due to random mutation, which happens at a relatively fixed rate). So examining the entire genome of multiple individuals from a given geographic area and comparing them to the genomes of individuals from other areas allows a fairly defined picture of what's called "substructure"; Native Americans share largely the same original gene pool, but at a genetic level they have enough data to be able to tell an Inuit from an Aztec from DNA.

[Coyotl]

10. As an anthropologist, i stand by my statement.

Albeit the grammar does not reinforce the idea that I worked on an advanced degree

"Latin Americans" designated persons from Spanish-speaking America. They could be Irish, German, Japanese, etc. in actual origin, but typically are a mixture of two gene pools, European and Native. Either the genes in question travel to the Americas from Asia or Europe.

[Spider Jerusalem]

13. Not a geneticist then.

Therefore probably not qualified to speak on the well-established and observable genetic differences between population subgroups.

[Coyotl]

20. Did take graduate courses though.

Qualified enough to say what I said!

[DonCoquixote]

5. As a Latino this makes sense

Of course the fact that a lot of our diet is rice and bread does not help, nor the fruits. I wonder if this applies to Mid-easterners, who have the same Diabetes issues.

[Lydia Leftcoast]

6. I remember reading that Neanderthals ate a largely meat diet

If that's the case, they may have been in the same situation as cats, who are obligate carnivores and tend to develop diabetes eating modern pet foods, especially those with grain fillers.

[DhhD]

7. Genetic markers for diabetes associated with metabolites, studied.

http://medicalxpress.com/news/2013-10-diabetes-associations-genes-metabolic-markers.html

[tclambert]

9. It all started when some father told his daughter, "I forbid you to date that Neanderthal boy!"

[Baitball Blogger]

11. Diabetes is not limited to Latin Americans.

I'm now sure where this study is going.

[DhhD]

15. Emergence is timed about 800,000 years ago. 4 of the 5 Haplo-type genes operate with the mutation

on Human Chromosome 17. (Haplo or haploid means one side of the homologue Chromosome 17.)

http://blogs.plos.org/dnascience/2013/12/25/did-mexicans-inherit-diabetes-risk-from-neanderthals/

The genes code for proteins that move metabolites across liver cell membranes and other lipid and plasma membranes.

https://www.ncbi.nlm.nih.gov/gene/162515

There are some internet sites that sale this protein but they can not be posted without permission. Could this form of diabetes be cured with a protein taken by mouth? Research Gene SLC16A11. (Same gene for rats and mice have same name but less capital letters in name.)

[Baitball Blogger]

19. The one thing I agree with, is that someone is taking the time to give Latin Americans

more attention. That would help in designing medicine that is customized for their personal make-up.

But, looking at the diet wouldn't be a bad idea either. We were raised with sugared sodas that were nothing more than liquid candy. And our candy was straight sugar. Sometimes sugar and coconut.

[Igel]

24. That's both the point and the problem.

The gene entered the H. sapiens gene pool very early. We hear about inbreeding in Europe. There were Neandertals SW Asia when H. sapiens left Africa. So the claim is that all H. sapiens outside of Africa include some Neandertal genes.

There are two kinds of diabetes. They're different.

Native Americans have a huge diabetes problem. Europeans and Asians, much less of one. One hypothesis is that natural selection is responsible--dietary changes after crop domestication in the ME 10k years ago led to diabetes-related deaths before reproduction. Natural selection. The hypothesis--now at least two decades old and pre-dating the Neandertal-interbreeding idea--was that indigenous diets didn't provide as large a dollop of relatively refined starches and sugars in the New World so there was no natural selection until "modernity" replaced the high-fibre, relatively meager diets of the majority of those with the greatest proportion of Native American ancestry with one that's high in fat, sugar, and starch.

Natural selection accounts for skin color, teeth shape, epicanthic folds, and a wealth of other differences between H. sapiens subtypes. No reason it can't provide adaptation to diets, as well. Of course, natural selection is brutal. It means that those who aren't as fit (according to whatever the criterion is) tend to be less successful at having offspring that survive to maturity. That might mean differential fertility rates; it might mean differential survival rates.

[Baitball Blogger]

27. Now I'm confused.

We can't claim that Europeans and Asians have less of a diabetes problems because of their genes, because food type could be a major factor.

Latin Americans either have Spaniard mix, or not. If they have Spaniard mix then their genes also have European origins. So why are they now susceptible to diabetes, when other European types are not?

Confusing.

[Dustlawyer]

12. Man, those Neanderthals really got around! They must have caught ancient AIDS!

[lunatica]

22. I love intelligent posts and discussions like this one!

Thanks for posting this. It's a fascinating subject. The inroads and discoveries in genetics is exciting! And once again I'm impressed with the intelligence and knowledge of DUers. I learn so much here.