The Archives of General Knowledge

Welcome to the Archives of General Knowledge, an informal publication where I will share with you lots of interesting facts, information, and many other useful stuff which you cannot easily find anywhere else!


Issue No. 1 [May-July 2014]

1. Race And Ethnicity: A Medical Perspective - Part One (May 28)

2. Research Highlights: A Molecular Basis For Blond Hair Color (June 2)


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EXO.Kris' Archives of General Knowledge is a forum topic on Hey-Ai that strives to present information that is interesting, up-to-date, and trustworthy.

If you are highly knowledgeble about a particular subject and wish to contribute, please suggest a brief outline of your article by replying below!

Race And Ethnicity From A Medical Perspective - Part I

May 28, 2014


Let's start by discussing something most of us on Hey-Ai are probably very interested in: the concept of race.

This is obviously a highly controversial issue, so we shall look at it from a strictly medical (scientific) perspective while steering away from all sorts of historical minefields that may hinder a constructive debate.

Remember, the Archives of General Knowledge is a place where you'll find lots of interesting information that isn't easily found elsewhere. Please be assured, however, that every effort has been made to ensure a high degree of accuracy for every claim found here.

The Classification Of Racial Groups

If you were to ask any medical researcher a simple question such as "What is a race?", or "How many racial groups are there on Earth?", he or she would probably struggle to give an answer!

The reason is that despite decades of intensive research, there is not a single definition or classification of "race" that is widely accepted by all researchers [1] .

For the sake of simplicity, however, let us stick to a fairly common description of races, as defined by the Medical Subject Headings [MeSH] of the U.S. National Library of Medicine in 2004:

"Groups of individuals whose putative ancestry is from native continental populations based on similarities in physical appearance." [2]

Now that we have a proper definition of race to work around with, we will need a general classification of different racial groups to continue the discussion.

While many of such racial classifications exist, very few of them are recognized to be definitive, and none of them are fully accepted in the academic fields.

However, there is a popular racial classification used by the U.S. government [3] , under which U.S. citizens are classified as :

1. Whites
2. Blacks
3. Asians
4. Native American Indians
5. Native Hawaiians or Pacific Islanders

According to the U.S. government, this is supposed to be viewed as a social construct, rather than a biological classification. [3] .

Contrary to these claims of the U.S. government, many DNA studies do in fact support such a biological classification of race into the 5 major groups above (4) . For example, when certain genetic markers known as single-nucleotide polymorphisms (SNPs) are measured, they may overlap among individuals from the same racial group, but generally do not overlap among individuals from different racial groups (4) .

The following illustration shows a simplified, evolutionary classification of human races based on DNA studies:


(Source: Genome Biology )

Let me summarize the current scientiific consensus by quoting a very relevant statement published in Nature Genetics:

"The emerging picture is that populations do, generally, cluster by broad geographic regions that correspond with common racial classification (Africa, Europe, Asia, Oceania, Americas). This is not surprising as the distribution of variation seen today is primarily the result of the history of human expansion out of Africa." (5)


An Important Caveat

Although current scientific evidence strongly suggests the existence of different racial groups, it is important for us to remember that humans, as a species, remain extremely similar on a genetic level (5) .

In addition, several social phenomena such as migration and intermarriage have resulted in the blurring of racial boundaries. For example, Ethiopians are known to share a great degree of genetic resemblance to Caucasians due to their close contact with Middle Easterners (4) .

Therefore, the best way to look at race is to treat it as a continuum.

In other words, human populations are never "pure" in a genetic sense, and, contrary to previous belief, definite boundaries between major racial groups do not exist and have never existed.

What's next?

In the next part of this article, I will discuss the extent to which a person's race affects his or her health. In addtion, I will also show you why (and how) different people of difference races are susceptible to different classes of disease.

If you consider these Archives of General Knowledge to be insightful, please click on the "Thank You" button so that I know people read my topics. If there are enough people clicking, I'll write the next article sooner!


References

1. www.ncbi.nlm.nih.gov/pubmed/15508000

2. www.ncbi.nlm.nih.gov/mesh/68044469

3. www.census.gov/population/race/

4. www.ncbi.nlm.nih.gov...icles/PMC139378

5. www.ncbi.nlm.nih.gov/pubmed/15507999

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EXO.Kris' Archives of General Knowledge is a forum topic on Hey-Ai that strives to present information that is interesting, up-to-date, and trustworthy.

If you are highly knowledgeble about a particular subject and wish to contribute, please suggest a brief outline of your article by replying below!

Research Highlights: A Molecular Basis For Blond Hair Color

June 2, 2014

Here at the Archives of General Knowledge, much emphasis will be placed on highlighting new research papers in the scientific literature.

Today, we will take a look at a study titled "A molecular basis for classic blond hair color in Europeans" , published on June 1, 2014, in the journal "Nature Genetics".


Who conducted this study?

Researchers at Stanford University (California).

What is the goal of this study?

As the title suggests, the aim of this study is to determine the molecular basis for blond hair in the Caucasian race. Although previous genetic surveys have demonstrated an association between several genes with blond hair , nobody really knew how these genes affect hair color on a molecular level.

What did the researchers discover?

The main finding is that a single-nucleotide polymorphism (SNP) known as "rs12821256" reduces the activity of the lymphoid enhancer-binding factor 1 , which affects the development and pigmentation of keratinocytes, thereby contributing to blond hair color.

Could you explain that in simpler terms?

Basically, a specific DNA mutation known as "rs12821256" affects the growth and development of hair cells, and ultimately results in blond hair color.

What type of mutation is this?

It is a simple point mutation that changes an adenine nucleobase into a guanine nucleobase. According to the researchers, this mutation has been found to be "prevalent" in Northern European populations, but it is "virtually absent in African and Asian populations.

What are the implications of this study?

Now that we know why some people have blond hair, it may be possible to uncover the other genetic changes that affect other types of hair color.

If genetic engineering technology continues to improve, it may eventually allow us to grow blond hair by changing a single molecule in our DNA, without the use of any artificial dyes!

And that means no more fake blondes!


References

Nature Genetics: A molecular basis for classic blond hair color in Europeans (June 1, 2014)

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EXO.Kris' Archives of General Knowledge is a forum topic on Hey-Ai that strives to present information that is interesting, up-to-date, and trustworthy.

If you are highly knowledgeble about a particular subject and wish to contribute, please suggest a brief outline of your article by replying below!