Joined: 07 Feb 2007 {Posts: 1829 } Location: Lookin DC Metro, Feelin Geneva
Posted: Tue 09 Dec 2008 00:00 Post subject: New Study on African American Admixture
Uhm...almost all African Americans can claim to be multiracial to some degree. I wonder how one can define "multiracial" as a group if almost all blacks fit into it by definition?
Quote:
PLoS Genetics doi: 10.1371/journal.pgen.1000294
Effects of cis and trans Genetic Ancestry on Gene Expression in African Americans
Alkes L. Price et al.
Abstract
Variation in gene expression is a fundamental aspect of human phenotypic variation. Several recent studies have analyzed gene expression levels in populations of different continental ancestry and reported population differences at a large number of genes. However, these differences could largely be due to non-genetic (e.g., environmental) effects. Here, we analyze gene expression levels in African American cell lines, which differ from previously analyzed cell lines in that individuals from this population inherit variable proportions of two continental ancestries. We first relate gene expression levels in individual African Americans to their genome-wide proportion of European ancestry. The results provide strong evidence of a genetic contribution to expression differences between European and African populations, validating previous findings. Second, we infer local ancestry (0, 1, or 2 European chromosomes) at each location in the genome and investigate the effects of ancestry proximal to the expressed gene (cis) versus ancestry elsewhere in the genome (trans). Both effects are highly significant, and we estimate that 12±3% of all heritable variation in human gene expression is due to cis variants.
Posted: Tue 09 Dec 2008 12:58 Post subject: Re: New Study on African American Admixture
Dragon Horse wrote:
Uhm...almost all African Americans can claim to be multiracial to some degree. I wonder how one can define "multiracial" as a group if almost all blacks fit into it by definition?
Quote:
Main Entry:
mul·ti·ra·cial
Pronunciation:
\-ˈrā-shəl\
Function:
adjective
Date:
1923
: composed of, involving, or representing various races
African-American admixture does not change the definition of "multiracial".
I think the more important question is - why do we keep harping on "various races". "White" Americans have some African and/or Native American admixture. African-Americans have anywhere from 3% (Gullah Island) to 35% (Seattle, Wash.) European admixture. Native American and East Asian ancestry cannot always be distinguished genetically. When will we learn?
Don't get me wrong, it's fun to find out about our genetic make-up and to study cultural and ethnic backgrounds. But, when we put MEANING to these things?
Posted: Tue 09 Dec 2008 14:40 Post subject: Multiracial
Is Dragon Horse saying that whites and Latinos are NOT "multiracial." Latinos are far more multiracial than "blacks." "Whites" include so many ethnic groups from different parts of the world that the diversity dwarfs the diversity claimed by American "blacks."
Joined: 07 Feb 2007 {Posts: 1829 } Location: Lookin DC Metro, Feelin Geneva
Posted: Tue 09 Dec 2008 15:26 Post subject: Re: Multiracial
Powell wrote:
Is Dragon Horse saying that whites and Latinos are NOT "multiracial." Latinos are far more multiracial than "blacks." "Whites" include so many ethnic groups from different parts of the world that the diversity dwarfs the diversity claimed by American "blacks."
LOL
No I am not saying or implying that. Hispanics are obvious.
The whites in this study don't look too "diverse".
They group together about as much as the Japanese LOL
I'm not counting "ethnicity" as race. Y ou can be the same race and be of different ethnic groups.
My point is, if you want multiracial to be an individual catagory...having a group means there are boundaries that define that group.
Are you going to draw some arbitrary line as to what is multiracial/biracial? If so what?
As you said...none of the major U.S. racial groups are relatively pure (but for individual East Asian nationalities...Japanese, Korean, and most Chinese Americans are not "mixed" but I guess that is beginning to happen more as mixed race people are claiming an Asian identity as well as a white one.
For example Powell you define people as "black"...how are you seperating out black from multiracial in the U.S.?
What makes someone black and not multiracial (if you don't know how they identify)?
Posted: Tue 09 Dec 2008 15:44 Post subject: Re: Multiracial
Dragon Horse wrote:
I'm not counting "ethnicity" as race. Y ou can be the same race and be of different ethnic groups.
DH has apparently forgotten that the rules of objectivity and replicability are stricter in the technical and scholarly forums than in the political advocacy forums. He has 24 hours to either produce an objective and replicable definition of "race" or to produce a peer-reviewed source published within the past ten years that affirms the biological reality of races (subspecies, breeds, varieties) in H. sapiens.
As the last sentence of rule 3.3.2 puts it: "Site members should be extremely cautious in using this term ["race"]. Its use without quotation marks tells nothing about the subject but reveals the ignorance of the user." The Technical and Scholarly group of forums does not tolerate that depth of ignorance. See also, rule 3.1.3 "Before posting an opinion on molecular anthropology or genetics, you must have read at least one introductory textbook on this topic and be able to name it."
Joined: 07 Feb 2007 {Posts: 1829 } Location: Lookin DC Metro, Feelin Geneva
Posted: Tue 09 Dec 2008 15:57 Post subject: Re: Multiracial
fwsweet wrote:
Dragon Horse wrote:
I'm not counting "ethnicity" as race. Y ou can be the same race and be of different ethnic groups.
DH has apparently forgotten that the rules of objectivity and replicability are stricter in the technical and scholarly forums than in the political advocacy forums. He has 24 hours to either produce an objective and replicable definition of "race" or to produce a peer-reviewed source published within the past ten years that affirms the biological reality of races (subspecies, breeds, varieties) in H. sapiens.
As the last sentence of rule 3.3.2 puts it: "Site members should be extremely cautious in using this term ["race"]. Its use without quotation marks tells nothing about the subject but reveals the ignorance of the user." The Technical and Scholarly group of forums does not tolerate that depth of ignorance. See also, rule 3.1.3 "Before posting an opinion on molecular anthropology or genetics, you must have read at least one introductory textbook on this topic and be able to name it."
Sorry, I should have defined this...
Race according to this site is:
Quote:
3.3.1 race (in biology) or bio-race — A sub-division of a species that is identifiable by a cluster of traits that vary together geographically. For example, the key lime and the Mexican lime are two races of Citrus aurantifolia that differ in several traits including peel thickness and color. Synonyms are: subspecies, variety, breed. No cluster of geographically co-varying traits (bio-race) has ever been found in Homo sapiens.
When I said race, I was not using the tem as in "subspecies", this does not exist in any human population..
If there have been no clustering of "geographically co-varying traits" found in humans than how is a study like this possible? The article below speaks specifically mentions lactose tolerance in East Africans and Europeans, skin color in Asians and Europeans, and a brain gene in Chinese and EUroepans..etc. Are these not co-varying genes that express co-varying traits?
I was using race in place of "population group" which is really what this study is based on.
That lactose tolerance has evolved independently four times is an instance of convergent evolution. Natural selection has used the different mutations available in European and East African populations to make each develop lactose tolerance. In Africa, those who carried the mutation were able to leave 10 times more progeny, creating a strong selective advantage.
Researchers studying other single genes have found evidence for recent evolutionary change in the genes that mediate conditions like skin color, resistance to malaria and salt retention.
The most striking instances of recent human evolution have emerged from a new kind of study, one in which the genome is scanned for evidence of selective pressures by looking at a few hundred thousand specific sites where variation is common.
Last year Benjamin Voight, Jonathan Pritchard and colleagues at the University of Chicago searched for genes under natural selection in Africans, Europeans and East Asians. In each race, some 200 genes showed signals of selection, but without much overlap, suggesting that the populations on each continent were adapting to local challenges.
Another study, by Scott Williamson of Cornell University and colleagues, published in PLoS Genetics this month, found 100 genes under selection in Chinese, African-Americans and European-Americans.
In most cases, the source of selective pressure is unknown. But many genes associated with resistance to disease emerge from the scans, confirming that disease is a powerful selective force. Another category of genes under selective pressure covers those involved in metabolism, suggesting that people were responding to changes in diet, perhaps associated with the switch from hunting and gathering to agriculture.
Several genes involved in determining skin color have been under selective pressure in Europeans and East Asians. But Dr. Pritchard’s study detected skin color genes only in Europeans, and Dr. Williamson found mostly genes selected in Chinese.
The reason for the difference is that Dr. Pritchard’s statistical screen detects genetic variants that have become very common in a population but are not yet universal. Dr. Williamson’s picks up variants that have already swept through a population and are possessed by almost everyone.
The findings suggest that Europeans and East Asians acquired their pale skin through different genetic routes and, in the case of Europeans, perhaps as recently as around 7,000 years ago.
SNIP
The concept of race as having a biological basis is controversial, and most geneticists are reluctant to describe it that way. But some say the genetic clustering into continent-based groups does correspond roughly to the popular conception of racial groups.
So for the sake of this conversation I will use "race" as a substitute for "continental based population clusters" found in this article since they heavily overlap with the notion of race we currently use in America.
Most whites in America have ancestry predominately from Europe or a border region of Europe.
Most "Asians" have predominant ancestral lines to the Asian continent.
Most "blacks" are predominately of subSaharan African ancestry...although due to social convention (one drop rule) there are those who are predominately or intermediate admixture of European ancestry who are "black" (African American) in the United States.
So this is my meaning.
The NY Times and the scientist in the article seem to support this notion that humans do have genetically based population clusters and that is (not perfectly) but fairly interchangeable with population notions of race, as we know it in the U.S. in 2008.
Posted: Tue 09 Dec 2008 16:25 Post subject: Re: Multiracial
Dragon Horse wrote:
I was using race in place of "population group" which is really what this study is based on. ... So for the sake of this conversation I will use "race" as a substitute for "continental based population clusters"...
In that case, there are hundreds of "races" in Africa, far more than around the rest of the globe combined. Since DH apparently has never read an introduction to physical anthropology, I again warn DH to stop posting his opinions in this forum.
Dragon Horse wrote:
... since they heavily overlap with the notion of race we currently use in America.
They do not. The only line in the article that suggests such a bizarre thing was, "But some say the genetic clustering into continent-based groups does correspond roughly to the popular conception of racial groups." This statement (given away by the weasel words "some say") was obviously inserted by the ignorant newspaper reporter. Scientific writing does not use weasel words.
If DH wants to ask this forum's genetics experts for an analysis of the ignorance displayed in the grotesque NY Times article, he should post his request as a new thread. To start, he may wish to consider that the person who drew the chart considers Native Americans and East Asians (specifically Mongolians) to be different populations. And yet, as we have discussed at great length here, autosomal DNA tests fail to distinguish them. Another point DH might consider is the usage "popular conception of racial groups." Whose popular conception? That of Brazilians?, Vietnamese?, New Guineans?, Arabs? What the writer (and apparently DH) means is "the unique bizarre U.S. conception of racial groups." Seriously, does DH really think that natural selection has evolved to match a notion that exists nowhere else on the planet, and has existed in North America for only about 300 years?
As it stands, DH is facing suspension in about 23 hours.
Last edited by fwsweet on Tue 09 Dec 2008 16:41; edited 1 time in total
What part of "If DH wants an analysis of the NY Times article, he should post his request as a new thread," does DH not understand? This thread is about a PLoS Genetics article. Second warning: DH should stop posting off-topic in this thread. He should open a new thread for the NY times newspaper article.
Last edited by fwsweet on Tue 09 Dec 2008 16:55; edited 1 time in total
Joined: 07 Feb 2007 {Posts: 1829 } Location: Lookin DC Metro, Feelin Geneva
Posted: Tue 09 Dec 2008 16:55 Post subject:
Another question. How can one definitively define "race" if biologist do not even agree on what constitutes a species?
There is no concensus on what a species is, there are some criteria but they are not "scientific laws" as there are obvious exceptions.
Quote:
a b c Hey J. 2001. Genes categories and species. Oxford University Press, New York, NY.
^ Endler JA. 1989. Conceptual and other problems in speciation. Pp. 625-648 in Otte, D, Endler, JA, eds. Speciation and its consequences. Sinauer Associates, Sunderland, Mass.
^ de Queiroz K. 1998. The general lineage concept of species: Species criteria and the process of speciation. Pp. 57-75 in Howard, DJ, Berlocher, SH, eds. Endless forms: Species and speciation. Oxford University Press, New York.
^ Miller W. 2001. The structure of species, outcomes of speciation and the `species problem': Ideas for paleobiology. Palaeogeography, Palaeoclimatology, Palaeoecology 176:1-10.
^ Hey J. 2006. On the failure of modern species concepts. Trends Ecol Evol 21:447-450.
^ Hull DL. 1999. On the plurality of species: Questioning the party line. Pp. 23-48 in Wilson, RA, ed. Species. MIT Press, Cambridge, MA.
All these people are still arguing what is a species and how to define one.
A race in the classical sense, as I believe the rules here define is a "sub species".
How can you define with accuracy a subspecies when no one is clear on what a species is?
For continuing to post about off-topic (about a NY Times article) in a thread about a PLoS article, after two warnings within the space of a few minutes, Dragon Horse's posting privilege is suspended until midnight, December 22, 2008.
Posted: Wed 10 Dec 2008 00:11 Post subject: Re: Multiracial
Powell wrote:
Is Dragon Horse saying that whites and Latinos are NOT "multiracial." Latinos are far more multiracial than "blacks." "Whites" include so many ethnic groups from different parts of the world that the diversity dwarfs the diversity claimed by American "blacks."
I agree 1000% that Latinos are far more mulitracial than "Blacks" (whites too if you can trust genetic studies). However, I don't understand how A.D. considers Whites more genetically diverse than Blacks? Africa is 3 times the size the continental US. Thousands of years ago when the first humans started to migrate, a much smaller percentage of man left and became known as Europeans versus those that remained in Africa. Is anyone here contradicting the belief that Africa has more "races" than Europe does?
Of course I do realize that the people who call themselves Afro-American today came from a population of mostly West and Central Africans in the 1700's, however America's first European population came from a mostly Northern European population as well. They were later joined by people from Southern &Eastern Europe and Middle Easterns that A.D. is using to prove White American diversity. If this is the case, than 'Blacks' could claim everybody in the US who has sub-sahara African ancestry from Obama, to any Somali, South African bushmen, to any Dafur refugee from Sudan to prove their diversity as well None of these groups of people would share African ancestry with the average African-American person.
Isn't African-American diversity part of the problem (even more so than European diversity) when it comes to medical research especially getting donors. African-American people often have a hard time matching donors even with other African-American people. In other words 'We' are diverse even without a drop of White blood.....
I remember the PBS special African-American lives where random AA celebrities like Oprah, Quincy Jones and Chris Tucker discovered their African roots. Everyone was linked back to a different ethnic group in Africa and even after learning this (as well as European ancestry in some cases) no one stopped thinking of themselves as Black or non- African-American even when science proved that they had no genetic ties to the other African-American people that were tested. Their ties were more historical: you had an ancestor that survived slavery from Liberia I had an ancestor that survived slavery from Nigeria. I seriously doubt the average Liberian or Nigerian family in Africa considers themselves the same ethnic group as one another even if people in America insist their African blood makes them an ethnicity:lol:
Last edited by girlfromthenc on Wed 10 Dec 2008 00:24; edited 1 time in total
Posted: Wed 10 Dec 2008 00:22 Post subject: Re: Multiracial
girlfromthenc wrote:
I don't understand how A.D. considers Whites more genetically diverse than Blacks? Africa is 3 times the size the continental US. Thousands of years ago when the first humans started to migrate, a much smaller percentage of man left and became known as Europeans versus those that remained in Africa. Is anyone here contradicting the belief that Africa has more "races" than Europe does?
Joined: 07 Oct 2007 {Posts: 248 } Location: United States
Posted: Wed 10 Dec 2008 02:12 Post subject:
I was guessing Powell was referring to "white" as being socioeconomic, without regard to genetics, in the way that East Asians are included in the "White" category (or so I've heard on this forum). Then again, this is the Molecular anthropology and genetics forum, so it's odd that she would use "white" in this sense unless it was to point out a race as a social construct and not a genetic one. And still, I'd be baffled why she would claim that "whites have diversity that dwarfs that claimed by blacks," especially because of the one drop rule.
Posted: Thu 11 Dec 2008 17:05 Post subject: Re: Multiracial
fwsweet wrote:
girlfromthenc wrote:
I don't understand how A.D. considers Whites more genetically diverse than Blacks? Africa is 3 times the size the continental US. Thousands of years ago when the first humans started to migrate, a much smaller percentage of man left and became known as Europeans versus those that remained in Africa. Is anyone here contradicting the belief that Africa has more "races" than Europe does?
Among the self-conscious popularizations of this new, post-Nazi racial economy of "difference" was a public exhibit entitled "Races of Mankind" based on Ruth Benedict's pamphlet of the same name. It was developed by the Cranbrook Institute of Science in 1943 and purchased by the American Missionary Association as a traveling show for use by any group "seeking o promote interracial understanding and goodwill through the medium of education." The main points of the exhibit were: 1) Nationalities are not races; (2) Jews are not a race; (3) There is no "Aryan" race; (4) the "Negro" is racially mixed (as opposed to that former "mongrel" the Mexican or other Hispanics); (5) There are three great "races" of mankind - white, black and yellow; (6) the "Caucasian" race has darker (West Asiatic) and lighter (European) branches. This was a conscious effort to expand the "white race" even further - to include Turks, Central Asians, Middle Eastern and North African peoples under the "Caucasian" umbrella.
Posted: Thu 11 Dec 2008 19:46 Post subject: Re: Multiracial
Powell wrote:
fwsweet wrote:
girlfromthenc wrote:
I don't understand how A.D. considers Whites more genetically diverse than Blacks? Africa is 3 times the size the continental US. Thousands of years ago when the first humans started to migrate, a much smaller percentage of man left and became known as Europeans versus those that remained in Africa. Is anyone here contradicting the belief that Africa has more "races" than Europe does?
Among the self-conscious popularizations of this new, post-Nazi racial economy of "difference" was a public exhibit entitled "Races of Mankind" based on Ruth Benedict's pamphlet of the same name. It was developed by the Cranbrook Institute of Science in 1943 and purchased by the American Missionary Association as a traveling show for use by any group "seeking o promote interracial understanding and goodwill through the medium of education." The main points of the exhibit were: 1) Nationalities are not races; (2) Jews are not a race; (3) There is no "Aryan" race; (4) the "Negro" is racially mixed (as opposed to that former "mongrel" the Mexican or other Hispanics); (5) There are three great "races" of mankind - white, black and yellow; (6) the "Caucasian" race has darker (West Asiatic) and lighter (European) branches. This was a conscious effort to expand the "white race" even further - to include Turks, Central Asians, Middle Eastern and North African peoples under the "Caucasian" umbrella.
I know my knowledge of North Africans is very limited ( I only know one person) but from conversations with this person, I really don't believe he will ever want to be categorized in the Caucasian branch at all.
He is a skinny kid with straight brown hair, green eyes (behind his bifocals of course) and pale complexion. I asked was he half middle eastern and half Caucasian and he responded that his family has traced their family for hundrends of years and everyone is Egyptian and he identifies as Egyptian and North African. I remember going to his church two or more years back ( I forget what affiliation it was) all the people he introduced me too were Egyptian with pale Italian/Meditterranean phenotypes with different color eyes. These were not the Egyptians I thought about when I thought about Egyptian people from my youth.
I have also met Middle Eastern's from Jewish as well as Islamic backgrounds and none of them chose to identify as Caucasian despite them all having Caucasian phenotypes with different colored eyes and hair.
They identify by their country of origin (Lebanon, Egypt) or region (Middle-Eastern, North African). It is easy for people on the outside to say there are only three races and add North African and Middle Eastern to the Caucasian branch but these people feel unique in their cultural make up and they have the right to be their own race despite phenotype.
Or, my greatest desire in this realm would be to abolish race altogether.
Posted: Thu 11 Dec 2008 20:24 Post subject: Re: Multiracial
onlyhuman77 wrote:
He is a skinny kid with straight brown hair, green eyes (behind his bifocals of course) and pale complexion. I asked was he half middle eastern and half Caucasian and he responded that his family has traced their family for hundrends of years and everyone is Egyptian and he identifies as Egyptian and North African. I remember going to his church two or more years back ( I forget what affiliation it was) all the people he introduced me too were Egyptian with pale Italian/Meditterranean phenotypes with different color eyes. These were not the Egyptians I thought about when I thought about Egyptian people from my youth.
Posted: Fri 12 Dec 2008 12:16 Post subject: Re: Multiracial
G-Man wrote:
onlyhuman77 wrote:
He is a skinny kid with straight brown hair, green eyes (behind his bifocals of course) and pale complexion. I asked was he half middle eastern and half Caucasian and he responded that his family has traced their family for hundrends of years and everyone is Egyptian and he identifies as Egyptian and North African. I remember going to his church two or more years back ( I forget what affiliation it was) all the people he introduced me too were Egyptian with pale Italian/Meditterranean phenotypes with different color eyes. These were not the Egyptians I thought about when I thought about Egyptian people from my youth.
I have also heard of these race books A.D. is speaking of. Its funny she should mention these philosophies, because the same people who try to expand the White race to include Middle Easterns and Asians (and sometimes East Africans) are normally the same ones who one-drop anyone left who isn't Latino or Arabic speaking into the Black race.
So again based on all these loose rules of race, the Black race would be just as broad!
'
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