People from Mexico show stunning amount of genetic diversity

http://www.sciencemag.org/news/2014/06/people-mexico-show-stunning-amount-genetic-diversity

by oscarwao • 10 years ago

106 135 10 years ago

jpablo• 10 years ago

As a Mexican I find the comment section nitpicking every word of the article as racist very funny. Americans have really thin skin. Political correctness is indeed drowning the exchange of ideas!

onli3• 10 years ago

Where do you see a comment section? Ah, maybe it is hidden in my browser.

It is looking at genetic differences between humans, which is something to be careful with. Though only US-americans (and Nazis, weird coincidence) think that genetic differences between humans mean that they are of a different race.

The article itself is less surprising than one might think. Mexicans in the north, center and south already look very different, with very typical types of looks being common in those areas. And I'm not talking about clothing and style here. It is not surprising that those visible differences show deeper differences.

hood_syntax• 10 years ago

only US-americans and Nazis

Citation needed.

wosos2• 10 years ago

Probably an adblocker is breaking the comments component.

SamBam• 10 years ago

Though only US-americans (and Nazis, weird coincidence) think that genetic differences between humans mean that they are of a different race.

I don't even know what this comment is supposed to mean. Is it saying that other nations don't subscribe to the notion of "race?" Because that's complete BS, as anyone who has travelled outside of the US would know.

Do we bring up apartheid in South Africa? European colonialism, and their views on race? Chinese views on race? Racism in Brazil? Saudi Arabia? Russia? I'm just confused as to what you mean.

Here's a simple example: The Wikipedia article on Race (human categorization), https://en.wikipedia.org/wiki/Race_(human_categorization), has a list of translations in the left column, with something like 60 languages listed. I can only read four others (Italian, French, Spanish and Portuguese), but they all say pretty much the same thing as each other.

I think any person with any understanding of the subject can agree that scientifically, the categorization of humans into "races" is meaningless and absurd, but this certainly doesn't mean that people all over the world do have this social construct. And most cultures also have a long list of stereotypes and assumptions that they apply to different "races."

wosos2• 10 years ago

As a fellow latin-american, I find it funny too but very worrying also, looks like a classic dogma and fact denying thing.

kazinator• 10 years ago

The HN discussion of the article is the real comment section.

rayiner2• 10 years ago

Americans have really thin skin because they fought a civil war over whether people with one color of skin could own people with a different color of skin. And until very recently,[1] people with one color of skin had to go to different schools than everyone else, they couldn't get married to each other, etc.

[1] To put things into context, Bill Gates, Steve Jobs, Larry Ellison, Jeff Bezos, and the other tech luminaries in their generation would have gone to segregated schools had they been born in the south instead of in California and Washington. If Ken Thompson had exercised his right to vote in his native Louisiana when he turned 18, he would have done so on ballots that, pursuant to state law, listed the race of each candidate.

The Voting Rights Act (which made it illegal to have "whites-only" hotels) and Loving v. Virginia (which ended laws banning interracial marriage) are roughly contemporaneous with UNIX--both being products of the late 1960s.

One more fun fact: Americans' approval for black-white marriage crossed the 50% mark sometime between the release of Windows 95 and Windows 98: http://www.gallup.com/poll/163697/approve-marriage-blacks-wh....

danso• 10 years ago

I don't know if it's so much as collective thin-skinnedness as it is that diversity is such a cornerstone of our society that we're forced to deal with the tensions it creates on a constant basis. This foments debate, much of it good, and some of it trollish, but I see it as a natural result of the freedoms and diversity that America has aimed to aspire.

I don't mean to say that achieving diversity is some kind of Grand Experiment designed by the Founders, but it's what we have because of our past and geopolitical circumstances, and we've struggled with and benefited greatly from it.

aaron-lebo7• 10 years ago

I'm from the South where this has been beat into us from youth. It's not fun to know that your state at one point seceded so the wealthiest elites could practice slavery. That and the Jim Crow laws are to our eternal embarrassment. The only good thing about it is our opportunity to learn from it.

I take some exception to your response, however, which seems very directed. There is not a single spot on this earth which hasn't had problems with racism, or a single one of us who has an ancestor who wasn't a racist. Latin America has its own problems with racism, as does Europe, Asia, and god-forbid even enlightened parts of the North and Pacific Northwest, too.

I don't disagree with your point, but I'm not sure of its relevance.

ycombinatorMan• 10 years ago

Hardly an excuse

pessimizer2• 10 years ago

To put things into context, Bill Gates, Steve Jobs, Larry Ellison, Jeff Bezos, and the other tech luminaries in their generation would have gone to segregated schools had they been born in the south instead of in California and Washington.

They still probably went to segregated schools. I certainly did, in Chicago, in the 80s. We had one white kid at our school from K - 8th grade. His name was Patrick. His stepfather was black, and his mom had died.

jomamaxx6• 10 years ago

" Bill Gates, Steve Jobs, Larry Ellison, Jeff Bezos, and the other tech luminaries in their generation would have gone to segregated "

I'll bet you $100 that Bill Gates' private school was 'de facto' segregated with almost zero, or in fact zero Black kids.

yummyfajitas• 10 years ago

This is a very good explanation of why some humans might have negative emotional reactions to a rational discussion of science.

Nevertheless, jpablo is right to call this out as a terrible failure of rationality on our part. 20 years before I was born, some folks that vaguely look like me were total jerks to other folks that look a bit different from me! That doesn't mean I should turn off my brain and reject science that triggers negative emotions.

Ignoring reality won't help us achieve our goals, whatever they happen to be.

logfromblammo• 10 years ago

You might not be aware of this yet, so read up a bit on sistema de castas [0].

Both Americans and Mexicans have the strength to change what can be changed, and the resolve to endure what cannot. But being American myself, I think that only the Mexicans also have the wisdom to know the difference.

Are you really going to cure racism with an essay written into the comments section of an article? Really? No. But we Americans are generally ashamed and embarrassed by those aspects of actual historical events that tend to contradict our beliefs in American ideals. One of those ideals being "all men are created equal", the natural conclusion is that America cannot be racist. But it is. It is so very racist. And so the idealists have to plug their ears and loudly sing "lalalalalala" whenever the actual evidence of it appears.

I'm glad that people of other nationalities find it amusing, but they don't have to live with those people.

[0] https://en.wikipedia.org/wiki/Casta

ChemicalWarfare3• 10 years ago

>Americans have really thin skin because they fought a civil war over whether people with one color of skin could own people with a different color of skin.

you do realize that there were black slaveholders as well? matter of fact, one of the (if not THE) first "officially documented" slaveholders was black (https://en.wikipedia.org/wiki/Anthony_Johnson_(colonist))

vectorpush3• 10 years ago

I'd hardly call uniformed commentary on the internet "political correctness drowning the exchange of ideas", however, it's ironic that those accusing the author of racism are inadvertently casting support for the racist idea that arbitrarily defined racial labels like "Mexican" have an inherent meaning that supersedes the actual genetics; the article is literally a case study of how our crudely defined racial groupings are insufficient descriptions of underlying genetics.

sremani• 10 years ago

Mexican is a nationality. I thought Hispanic was more race/ethnicity.

What do you call a citizen of Mexico?

panglott• 10 years ago

Some of the nitpicking is funny, but the lede is kind of terrible: "Imagine if people from Kansas and California were as genetically distinct from each other as someone from Germany is from someone from Japan."

Just imagine if California contained people as genetically distinct as a person from Germany and a person from Japan!

kbenson11• 10 years ago

I understand what the lede is trying to say, and I understand what the average (that is, mean) person probably thinks. Take a random person from that place. I think it's more likely the author meant take the median, or even better for diverse locations, the mode.

This is exacerbated by the believe of Americans (myself included) that we are a uniquely diverse place, reinforced by our education and mythology. We're diverse. We aren't that diverse.

P.S. It is rather funny that California was used in that example rather than some other state. It's one of the few states approaching the level where the majority population will soon buy Hispanic, if it isn't already, making the statement somewhat pointless.

badsock• 10 years ago

Sometimes it's hard to see the importance of racism for someone who isn't part of a minority group day-in-and-day-out. In terms of racial identification, are you part of the majority in your country?

armandososa2• 10 years ago

As a fellow Mexican I agree with you. Except that we are slowly becoming as thin skinned as our gringo neighbours because of social media.

kavbojka• 10 years ago

I don't think Mexico has had to confront its own issues with race in any meaningful way. We'll see you on the other side, friend.

sandworm1012• 10 years ago

Why the surprise? Mexico is part of a land bridge between two continents. Both have been invaded multiple times by distant populations. It's next to the Caribbean, a host of islands which are known to accelerate genetic changes. With all these peoples coming and going I'd be shocked if it wasn't so diverse.

noahc• 10 years ago

Why are the islands known to accelerate genetic changes specifically? Is it because of sun exposure?

rmcfeeley• 10 years ago

Isolation. See The Galapagos + Darwin's studies on the birds there. Also: Madagascar (film + land mass)

stevedt• 10 years ago

I Googled "islands accelerate genetic changes" and the results show stuff like:

The restricted scale, isolation, and sharp boundaries of islands create unique selective pressures, often to dramatic effect.

sandworm1012• 10 years ago

From what I've read about animals, the isolated population of an island results in faster evolution due to 'close' breeding. Rare non-dominant genes are more likely to meet up and be expressed. The lack of geographic diversity also means that species need not evolve to be generalists. There is no advantage to adapting to anything but the island environment. In humans, by way of example, that might mean an island population more rapidly adapts to an endemic disease as they cannot escape it. They don't have people living elsewhere brining in non-adaptive genes and so the local adaptive genes spread more quickly than if they were on the mainland.

mc32• 10 years ago

That may be so but the take away should be it's not just intuition but it's documented and contributes to scientific knowledge and inquiry and may lead to direct improved knowledge about those pops leading to better medical understanding and treatments... And no just for them but other genetically divergent groups around the world.

huherto2• 10 years ago

There are two big mountain ranges crossing Mexico North-South. That probably kept some of the indigenous groups isolated from each other for a long time.

There is also the division between Mesoamerica (South) and Aridoamerica(North). Two different sets of cultures that needed different technologies. Settlers and Nomads.

BurningFrog2• 10 years ago

My understanding is that all native american populations are from a relatively small and homogenous population that walked into Alaska 16000 years ago.

Which means that they're much less genetically diverse than the rest of the world.

This is hard to reconcile with the claims in this article.

JoeAltmaier• 10 years ago

Homo Sapiens has done more gene specializing in the last 50,000 years than in the previous 2 million. So it makes good sense.

hx87• 10 years ago

While founder effects do reduce genetic diversity within a given population, reproduction and adaptation do increase it.

Also, Mexican =/= Native American

BurningFrog2• 10 years ago

The article is about the native populations.

mhewett• 10 years ago

Latest information is that there were at least two, maybe three waves of immigration from Asia. There were probably also small numbers of people who made it from Polynesia to South America.

tokensimian• 10 years ago

I encourage you to read the wikipedia article on the settlement of the Americas, mostly because it's fun[0].

The landbridge theory has its supporters, but what's really interesting is the gaps in knowledge, and other theories about multiple waves of settlement, or settlement directly from seafaring peoples.

It's really just a fascinating mix of fields. You do yourself a disservice by reducing the settlement of the americas to 2 sentences like that.

I do believe the claim of less genetic diversity amongst indigenous Americans is correct. The excellent book "1491" even discusses how this could have contributed to the spread of disease: less genetic diversity meant less overall population protection.

[0] https://en.wikipedia.org/wiki/Settlement_of_the_Americas

betolink• 10 years ago

I remember a little while ago my dad went to an academic lunch with Dr. Craig Venter in Chiapas (MX), he was talking about sampling DNA from the Americas to register genes that could potentially help medical research and are endemic to the region.

jkot• 10 years ago

Imagine if people from Kansas and California were as genetically distinct from each other as someone from Germany is from someone from Japan.

Is not this a case? People immigrated to america from many continents.

tuna-piano2• 10 years ago

I've often wondered why Mexican people look so different from people in the US. Wikipedia makes me believe that Mexicans are generally a mix of European and native ancestry. But why does Mexico have so much more of that than the US? Especially considering we stole much of our land from them...

Why does the average person in Texas (excluding Mexico->US immigrants) look so different from the average person a few hundred miles south, but yet looks similiar to someone a few hundred (or thousand) miles north?

saint_fiasco• 10 years ago

Wasn't interracial marriage illegal in the US until the 20th Ceentury?

dragonwriter6• 10 years ago

Wasn't interracial marriage illegal in the US until the 20th Ceentury?

Yes, and no. That is, it wasn't established as a federal Constitutional right until the decision in Loving v. Virginia (1967), but there were many states where it was legal prior to that (in fact, it was legal in 6 of the 13 original colonies at the time of independence, and there are several states that never passed laws prohibiting it.)

And even then, the laws that were passed only consistently prohibited whites from marrying blacks, though some of them also included all or specific other non-white "races".

huherto2• 10 years ago

Wikipedia makes me believe that Mexicans are generally a mix of European and native ancestry.

The interesting aspect of the article is that the "native ancestry" part is very diverse itself.

But why does Mexico have so much more of that than the US?

The Spanish mixed with the native population and created communities with them since the beginning. This process is 500 years old. Race boundaries have been erased. In the US this process is 100-200 years old.

Especially considering we stole much of our land from them...

A lot of the land was very sparsely populated. Most migration to the West occurred after the 1840s. People coming from the East (NY, Boston, Philadelphia, Louisiana, etc). This explains why they are so similar to them.

falsestprophet2• 10 years ago

"The Spanish mixed with the native population and created communities with them since the beginning. This process is 500 years old. Race boundaries have been erased."

It isn't true that boundaries have been erased, though it may seem that way because a majority of Mexicans are mixed European and indigenous (62%).

But about 10% is European, 7% indigenous and 21% predominantly indigenous.

https://en.wikipedia.org/wiki/Demographics_of_Mexico#Ethnic_...

pesfandiar• 10 years ago

Someone more knowledgeable can correct me if I'm wrong, but the diversity of Mexico might have to do with how strong the Central American nations were at the time of colonization. They had huge cities and much more complex government systems than their Northern native neighbours. There was thus less massacres and more intermingling down there.

The modern distinction may have been caused by the border itself (e.g. if you are a new immigrant in US, you probably have better opportunities away from the border).

senorjazz2• 10 years ago

I think I read somewhere, that as the central and south American civilisations were settled, with towns, cities and a ruling elite. The Spanish just replaced this ruling elite.

Whereas in north America, it was more nomadic peoples, so the Europeans couldn't just replace the existing rulers and carry on as normal, thus the eradication policy.

w1ntermute2• 10 years ago

Because the population density was much lower in pre-Columbian America than in pre-Columbian Mexico[0]. Note how Argentina has a similarly low population density - their current population also has a low level of indigenous ancestry.

There are some other nuances as well, like how the existing social structure was preserved in Mexico. Check out Why Nations Fail[1] for the details.

0: http://i.imgur.com/RI3uplJ.jpg

1: https://en.wikipedia.org/wiki/Why_Nations_Fail

tuna-piano2• 10 years ago

Yes, the population map is exactly what I was looking for - makes total sense and explains the differences.

Thanks

mrtree8• 10 years ago

"Population density"is a nice way to put it but hides fact that the local population was exterminated in the british colonies, and not in the spanish ones. That's why there is so few people of aboriginal descent in the US and not in Latin America.

dragonwriter6• 10 years ago

Wikipedia makes me believe that Mexicans are generally a mix of European and native ancestry. But why does Mexico have so much more of that than the US? Especially considering we stole much of our land from them...

Because the US (starting before it was the US) engaged in policy of separation from, genocide against, and subjugation-in-separate-polities of the natives, whereas the Spanish in Mexico (and elsewhere) implemented the encomienda system (essentially, a quasi-feudal manor system, where the natives were essentially in the role of peasants, but -- by royal decree -- free peasants, not chattel slaves like blacks in the US.)

elboru• 10 years ago

Well you would have to understand that Mexico is a mix, but not a perfect mix. Southern Mexican states have more Indigenous people, and mestizos there have more indigenous characteristics, but if you go to Northern states it won't be difficult to find blond people, that's because there were less native Americans in the north than in the south.

Then you have to understand that the poorest states of Mexico are in the south, therefore a lot of people from the South emigrates to the US, and that's where Americans get the stereotypical look for a Mexican.

As an anecdote, I live in a Mexican Northern state, in my last year of college I got the opportunity to study as an exchange student in Charleston S.C., I went there with other 3 students, the three of them were what Americans would call "White", some people were confused, how a Mexican could be white? They had a clear picture of how a Mexican should look like, and usually that picture comes from Mexicans with a little more indigenous blood in their veins, as myself, I have black hair and my skin is clear brown even though two of my grandparents had blue eyes.

So yeah, it all depends on where in Mexico you go, there are white Mexicans, native american Mexicans, even black and Asian Mexicans in the whole territory but we're part of a not so perfect mix, there are zones where one genetic pool is stronger than the other.

mrtree8• 10 years ago

Because the native aztec population was not exterminated as the indians in US were. The spanish mixed with the locals but there weren't that many of them (spanish).

HillaryBriss• 10 years ago

conjecture: the population of Los Angeles County, if measured using the same approach employed by this study, would show more genetic diversity than the population of Mexico

vondur• 10 years ago

Well, it's not surprising given the racial makeup of the Iberian peninsula over history. (Celts, Romans, Vandals, North Africans) and then sending them to America to mix with native Indian populations and imported Africans.

crpatino• 10 years ago

That's what I thought at first. The interesting thing about the article is that it shows the native population was already pretty diverse by the time of first contact with the Europeans.

Also, a minor nit picking. Even if slaves brought to Mexico came from a very specific Portuguese enclaves within the African continent, the population within Africa is extremely diverse. It would not surprise me if they brought about as much diversity as the other two source "races", for lack of a better word. It seems a bit too simple to have them reduced to a note margin as in "imported Africans".

amelius• 10 years ago

Genetic diversity is said to result in better traits. So what are these traits in this case?

People from Mexico show stunning amount of genetic diversity

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