May 4, 2012

The Blonds of Guadalcanal

From the New York Times:
In the Solomon Islands, about 10 percent of the dark-skinned indigenous people have strikingly blond hair. Some islanders theorize that the coloring could be a result of excess sun exposure, or a diet rich in fish. Another explanation is that the blondness was inherited from distant ancestors — European traders and explorers who came to the islands. 
A team led by researchers at Stanford University has identified a gene that is responsible for blond hair in 5 percent to 10 percent of the indigenous population of the Solomon Islands. 
But that’s not the case, researchers now report. The gene variant responsible for blond hair in the islanders is distinctly different from the gene that causes blond hair in Europeans. 
“For me it breaks down any kind of simple notions you might have about race,” said Carlos Bustamante, a geneticist at Stanford University. “Humans are beautifully diverse, and this is just the tip of the iceberg.”

For me, it builds up my simple notion that race is less about what you happen to look like than about who your relatives are. We can of course use appearance to guess at who your relations are, but if we have DNA data or long documented pedigrees, as with thoroughbred racehorses, we can skip the classification-by-appearance step.

31 comments:

Weltanschauung said...

There's a sentence out of place in this excerpt. Shouldn't

But that’s not the case, researchers now report.

come immediately after

Another explanation is that the blondness was inherited from distant ancestors — European traders and explorers who came to the islands.

?

Anonymous said...

"For me, it builds up my simple notion that race is less about what you happen to look like than about who your relatives are."

Suppose half you relatives are black while half the people of another race look/feel/think like you. I think you might go with folks of other race.

Anonymous said...

I welcome our Guadalcanalian master race overlords.

Marlowe said...

Did one of these guys become Wesley Snipe's character in Demolition Man?

Propeller Island said...

The gene variant responsible for blond hair in the islanders is distinctly different from the gene that causes blond hair in Europeans.

Not just different but distinctly different. No European taint there at all!

Peter A said...

We can of course use appearance to guess at who your relations are, but if we have DNA data or long documented pedigrees, as with thoroughbred racehorses, we can skip the classification-by-appearance step.

Right - which is why Obama is essentially a white man despite his appearance.

Catperson said...

For me, it builds up my simple notion that race is less about what you happen to look like than about who your relatives are. We can of course use appearance to guess at who your relations are, but if we have DNA data or long documented pedigrees, as with thoroughbred racehorses, we can skip the classification-by-appearance step.

To me race is about genetic similarity. Since similar genes code for similar appearance, race can be largely deduced from looking at people.

Back in the good old days there were only 3 races: Negroid, Caucasoid and mongoloid. Some added australoids but other considered these a form of Negroid or archaic Caucasoid.

But then with the genetic revolution we found that negroids and australoids (including Papuans) had been genetically isolated for tens of thousands of years and not only were not the same race, but were among the most unrelated two groups.

However just because they are genetically unrelated, does not mean they are genetically dissimilar. Surely there similar appearance implies similar genes, if only because they evolved in similar environments.

But scientists use junk DNA because it's uninfluenced by evolution and thus serves as an unbiased measure of ancestry. On junk DNA negroids and australoids are genetically distant, but TOTAL DNA might show that 19th century scientists were correct to lump australoids into the Negroid race.

dearieme said...

"“For me it breaks down any kind of simple notions you might have about race” he said, having the presumption to assume that he knew what my notions might be because I look white. Racist bastard!

dearieme said...

The left wing theology of Race is just so bloody boring compared to the factual stuff, isn't it?

Nanonymous said...

So, a really good example of drift, most likely.

Anonymous said...

Catperson,

It is likely that Australiods are the furthest from Africans. They have the most non-African DNA of all genetic groups. Nearly 8% Denisovan, and 4% Neandertal makes takes them a long way from the African root.

TWS

catperson said...

It is likely that Australiods are the furthest from Africans.

That might be true with respect to junk DNA, but perhaps if total DNA was considered they would cluster with Africans because they've both lived in equatorial environments for so long. In junk DNA they are far apart because junk DNA measures common ancestry, but total DNA measures common traits selected by common environments. The question is which is the more logical way of sorting race.

Hail said...

I think the NYT is misquoting the anthrpologists behind the study. As I have read, they state that they estimate "5-10%" of the children have blond hair.

If anything like among Europeans, a far lower percentage of adults will retain blond hair.

Prof. Woland said...

Only their hair dressers know for sure.

Anonymous said...

When people say 'blonde' they don't just mean the hair color but all the physical attributes that come with being 'Scandinavia' or Germanic. So, people who like 'blondes' will take a German or Swede with black hair over a non-white with blonde hair.

Anonymous said...

Similarly, 'black' isn't just a skin color. Many Asian-Indians are black or dark-skinned, but they are not the sort of men who turn on jungle-feverish women. When jungle-feverish women talk of blackness, they don't just mean skin color but muscle tone, stature, and whanker size.

Anonymous said...

Phenotypes (observable characteristics) are not genotypes (genetic information). News at 10.

Anonymous said...

Another example that Cochran's right about geneticists being pretty limited.

Tom said...

“Humans are beautifully diverse, and this is just the tip of the iceberg.”

It's palpable that Carlos can't wait for us to breed that diversity into extinction.

Steve Sailer said...

"they state that they estimate "5-10%" of the children have blond hair."

Why is the hair of small children often fairer? Is it just smaller, wispier?

Anonymous said...

For me, it builds up my simple notion that race is less about what you happen to look like than about who your relatives are.

Depends on what you mean by relatives and look like.

I don't think anyone would consider a clone of a Black guy with all his junk (non functional) dna switched to a White guy's to be a White guy, even though his co-efficient of relatedness would be that same with Whites as a typical White.

Race is not clearly either just about phenotype or relatedness, since the concept, as Cochran has stated, derives from related subgroups who are phenotypically distinct in a sufficiently interesting way.

But scientists use junk DNA because it's uninfluenced by evolution and thus serves as an unbiased measure of ancestry. On junk DNA negroids and australoids are genetically distant, but TOTAL DNA might show that 19th century scientists were correct to lump australoids into the Negroid race.

This is very wrong. Autosomal clustering uses the entire (or an unbiased/random selection of) the genome.

If you want to say "Perhaps Australian Aborigines and Africans are more similar on functional genes to one another than they are to their closer outgroups (Europeans and East Asians, respectively)" then perhaps that is correct. But what you are saying is certainly wrong.

Anonymous said...

It's pretty obvious to me who is responsible for these kids:

http://bookriot.com/wp-content/uploads/2012/02/charlie-bucket.jpg

Peter Frost said...

In Europeans, hair color varies with age and sex, i.e., it's lighter in children and women.

This study is interesting because it suggests that a common selection pressure (generated by a common mental algorithm?) favors lighter hair color in children. To varying extents, this same selection pressure also favors lighter hair in women.

Svigor said...

Why is the hair of small children often fairer? Is it just smaller, wispier?

No, it's something about gene expression, I think. I forget even the broad strokes, but it isn't just smaller/wispier, IIRC.

Anonymous said...

Children with blonde hair have blonde hair because they are children with blonde hair. As they age it gets darker.

Freddy said...

"Anonymous catperson said...

It is likely that Australiods are the furthest from Africans.

That might be true with respect to junk DNA, but perhaps if total DNA was considered they would cluster with Africans because they've both lived in equatorial environments for so long. In junk DNA they are far apart because junk DNA measures common ancestry, but total DNA measures common traits selected by common environments. The question is which is the more logical way of sorting race.""


- I see someone needs to go back to genetics 101...

Anonymous said...

Did you forget your own work? Test darkens hair. Our hormones do that, that is why women work to lighten and add sheen to their hair. You covered this topic in interracial dating iirc.

TWS

pat said...

It is well known that there are blond Australian Aborigines. This would seem to remove the need for European connections.

Albertosaurus

Catperson said...

If you want to say "Perhaps Australian Aborigines and Africans are more similar on functional genes to one another than they are to their closer outgroups (Europeans and East Asians, respectively)" then perhaps that is correct.

That's what I mean. If we sorted humans by functional DNA we might get a more logical picture of race, but a lot of the genetic linkage trees are based on junk DNA. Junk DNA is used because it's not sensitive to natural selection, so differences in junk DNA reflect only divergence time (from a common ancestor) and thus sort humans by Steve's definition of race (relatedness). However what good is it to be closely related if rapid natural selection as made you different? That's why functional DNA is a better way to measure race? Africans and Australoids may have been separated for tens of thousands of years, but having both stayed in the ancestral warm climate, both closely resemble their common ancestor (and thus each other)for all practical purposes.

Ted said...

"That's what I mean. If we sorted humans by functional DNA we might get a more logical picture of race, but a lot of the genetic linkage trees are based on junk DNA. Junk DNA is used because it's not sensitive to natural selection, so differences in junk DNA reflect only divergence time (from a common ancestor) and thus sort humans by Steve's definition of race (relatedness). However what good is it to be closely related if rapid natural selection as made you different? That's why functional DNA is a better way to measure race? Africans and Australoids may have been separated for tens of thousands of years, but having both stayed in the ancestral warm climate, both closely resemble their common ancestor (and thus each other)for all practical purposes."

- Catperson, in this case, why use DNA at all? What you are describing is better suited to qualitative analysis of phenotypic traits - skin,eye, and hair color, body size, adaptations to temperature, etc.

Convergent evolution opens major cans of worms when trying to analyze coding genes for ancestral divergence. What you want for a molecular clock is junk DNA- something not under selective pressure, that changes by random processes, that over many millenia will reliably give you an estimate of the divergence. There are problems with this- generation times, etc that can affect the rate- but within the same species, it may not be much of an issue.

A bigger problem, I think is that there is increasingly the recognition that alot of "junk DNA" is not turning out to be junk at all- miRNAs, etc. that may well be under selective pressure. So it calls into question the validity of molecular clocking at all.

Catperson said...

- Catperson, in this case, why use DNA at all? What you are describing is better suited to qualitative analysis of phenotypic traits - skin,eye, and hair color, body size, adaptations to temperature, etc.

Good point. I guess for me functional DNA is just a very thorough and objective measure of total inherited relevant biological similarity.

According to Steve, australoids and Africans are not the same race because they're not related, and their common appearance is deceptive. To Steve, race is about sharing recent ancestry, regardless of appearance.

But I propose that races should be classified not by time (how long ago they did or didn't split) but by how much evolution occurred in that time.

Based on divergence time, Australoids are extremely distant from the African root of the human tree, but because of convergent evolution, they never really progressed past the Negroid stage of human evolution, and thus should arguably be classified as Negroid since they preserved the traits of their African ancestors. Other populations might more closely related to Africans, but they experienced rapid natural selection in vastly colder environments, causing them to lose their African traits and evolve to the next level.

So race should not be about how related you are, but how much of your common ancestry you and your relatives preserved. Distant relatives can thus share a race that closer relatives are excluded from because the unit of analysis becomes evolutionary history, not divergence time.

Junk DNA has Africans and Australoids in very different racial clusters, but I'm thinking an analysis of functional DNA could correct this.