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Allenson
Friday, August 29th, 2003, 04:55 PM
Hi friends,

I found an interesting article on the www.racearchives.com/archived/ website about genetic structures and patterns within and between Americans of European, African and Hispanic ancestry. As the PDF file of this article is surely too large to attach to a post here I have again uploaded it to the NEA (formerly SNPA) Yahoo web page. It can be found in the 'files' section and I called it "Americangenes" The article can also be found here: http://www.genome.org/cgi/content/full/13/4/624 if you have access to this online journal.

It was a fascinating read and may likely be of interest to many of us "New Worlders" to see just where we stand in terms of ancestry and admixture.

The following are a few highlights that I was able to glean from the article:

The study looked at similarities and differences within and between American groups of European, African and Hispanic descent. Samples were taken from many places around the US: Washington, Oregon, California, Texas, Louisiana, Missouri, Illinois, Indiana, Florida, Virginia, Pennsylvania, Maryland, New York, Connecticut and Vermont (how did they miss me?! :) ). Both Y-chromosome and mtDNA haplogroups were used and compared in this study.

~All groups included could be clearly differentiated from each other at a genetic level. In fact, here is one very interesting quote from the article: "The results indicate that Y STR (Y-chromosome) haplotypes differ significantly between African-American, European-American and Hispanics; ~25% of the genetic variance reflects differences between these populations...."

~In terms of Y-chromosome haplotypes, the European-Americans and the Hispanics were more closely grouped and the African-Americans distinctly clustered together significantly away from the other two.

~Here is another interesting quote: "We also compared the U.S. populations to worldwide data for haplotypes for the same nine Y-STR loci. An MDS plot (Fig. 3) shows that sub-Saharan African and African-American groups are clustered together, separate from the other groups. Hispanic groups tend to be associated with populations of Asian and European ancestry, whereas European-American groups tend to be associated with European populations, but there is some intermingling between Asian/Hispanic and European/European-American groups. A neighbor-joining tree shows the same groupings (data not shown). " I interpret this as showing the Spanish paternal legacy of the Hispanic population revealing itself as well as the admixture of American Indians revealing itself here in the word "Asian".

~While there was some overlap between the Euro-American and Hispanic Y-Chromosome haplogroups (again, showing the Spanish paternal contribution to the Hispanic gene pool) the mtDNA results were very different. mtDNA haplogroup analysis significantly separates the Euro-American and Hispanic populations. There researchers postulate and I personally can not help but agree, that this is a reflection of the American Indian maternal contribution to the Hispanic population. Conquistadors took their squaws apparently! This is often widely noted among historians and now there appears to be genetic evidence to back it up.

~The study showed that there is an overall lack of heterogeneity among Euro-American populations with regard to geography in the US both in terms of Y-Chromosome and mtDNA haplogroups. In other words, Euro-Americans are very similar to each other regardless of where they might be from. A white Vermonter ain't all that different from a white Georgian. :) Here's a quote from the article: "The overall lack of geographic heterogeneity among European-Americans is not surprising, as European populations exhibit little differentiation with respect to Y-STR haplotypes (Roewer et al. 2001) and mtDNA types (Melton et al. 1997b). "

~The study reckons that the Euro-American contribution to the African-American gene pool is around 20% which very much agrees with other studies that have been performed on this very subject. Interestingly enough, the male, or Y-chromosome Euro-American contribution is quite a bit larger than the female or mtDNA DNA; ~27.5% - 33.6% for male and 9% - 15% for female which rough out to the 20% overall estimate. Again, this is in accordance with the age-old notion of historically more white males getting busy with slave women than visa-versa. Alas though! The author noted the reversal of this trend in recent decades citing census data that shows the increase in African-American men and Euro-American women marrying. :(

Signing off on a brighter note, I quote the following about another inquiry of this particular study: "The latter result indicates that the African-American genetic contribution to European-Americans is below the limits of detection with these methods."

cheers all!

Loki
Friday, August 29th, 2003, 05:29 PM
Signing off on a brighter note, I quote the following about another inquiry of this particular study: "The latter result indicates that the African-American genetic contribution to European-Americans is below the limits of detection with these methods."



This is a great quote!! I hope the politically correct and the evolutionary blind take notice...

It is also refreshing to see a genetic study which is not rigged with a liberal race-mixing agenda. Well done!

Allenson
Friday, August 29th, 2003, 06:58 PM
This is a great quote!! I hope the politically correct and the evolutionary blind take notice...

It is also refreshing to see a genetic study which is not rigged with a liberal race-mixing agenda. Well done!

Yes indeed! I particularly enjoyed it myself and read it through several times just to make sure my eyes weren't deceiving me!

Agreed. The article did not smack of political agenda at all and that was most refreshing.

Tore
Saturday, August 30th, 2003, 08:48 AM
"Signing off on a brighter note, I quote the following about another inquiry of this particular study: "The latter result indicates that the African-American genetic contribution to European-Americans is below the limits of detection with these methods."

I'm sure "Racial Myths" is kicking himself over this one. :)

Nordhammer
Wednesday, February 18th, 2004, 03:10 AM
Important excerpts:

The African-American genetic contribution to European-Americans is below the limits of detection with these methods. (In other words, practically non-existent. I suppose this may be different with other DNA studies because of the specific isolation of European-Americans, rather than the more ambiguous "white" group. The latter may include individuals of recent non-white admixture yet still call themselves white and non-Europeans who may have more admixture.)


European-American genetic contribution to African-Americans (Table 5) was much higher for the Y-chromosome than for mtDNA; ~27.5%-33.6% of African-American Y-chromosomes were determined to be of European-American ancestry versus only 9.0%-15.4% of African-American mtDNAs.

We found no significant heterogeneity among regional groups of African-Americans, which seems somewhat surprising for two reasons. First, a large number of different African source populations contributed to present-day African-American groups, with about half coming from the area extending from Senegal to Western Nigeria, and the remaining half coming from the area extending from Eastern Nigeria to Angola (Curtin 1969; Reed 1969). However, the amount of genetic heterogeneity among these West and Central African source populations that contributed to African-Americans is not known, as a comprehensive study of genetic variation in these populations has not been carried out.

Second, the amount of admixture of African-Americans with European-Americans is thought to have varied across different geographic regions of the U.S., with generally higher levels of admixture observed in Northern groups (Reed 1969; Chakraborty et al. 1992).

A further complicating factor is migration among geographic regions within the United States. Even with heterogeneity in the founding West African populations and/or the subsequent amount of European-American genetic contribution to African-Americans, migration of African-Americans within the United States may have been extensive enough to eliminate between-group differences in Y-STR haplotype frequencies. In particular, during and following World War I, an estimated one million African-Americans (~10% of the African-American population) left rural areas in the southern United States for metropolitan areas in the north (Johnson and Campbell 1981; Tanner 1995). The lack of geographic heterogeneity observed in African-American mtDNA and Y-chromosome types may thus reflect this "Great Migration", the largest internal migration in the history of North America.

The overall lack of geographic heterogeneity among European-Americans is not surprising, as European populations exhibit little differentiation with respect to Y-STR haplotypes (Roewer et al. 2001) and mtDNA types (Melton et al. 1997b). However, the striking uniformity among regional groups of Hispanics for both Y-STR haplotypes and mtDNA types (see Fig. 4) is surprising, given that Hispanic does not refer to a defined geographic region, in contrast to European-American and African-American. Instead, the ethnic category, Hispanic, typically can refer to someone of Mexican, Puerto Rican, Cuban, Central/South American, or other Spanish culture ancestry (Chakraborty et al. 1999), and previous analyses have estimated varying degrees of native American, Spanish, and African ancestry in Hispanic populations (Hanis et al. 1991; Merriwether et al. 1997; Chakraborty et al. 1999).

For the mtDNA SSO-types, the Hispanic and European-American groups were completely separated from one another (Fig. 4), whereas for the Y-STR haplotypes, there was some intermingling of Hispanic and European-American groups.

It appears that the paternal and maternal structure of Hispanic groups differ, most likely reflecting a greater contribution of European-American Y-chromosomes than mtDNA haplotypes to the Hispanic gene pool. Although insufficient data from potential source populations among native North American, Central American, and Caribbean populations exist to permit estimates of admixture for Hispanic groups on the basis of Y-STR haplotypes or mtDNA SSO-types, other studies have found a greater contribution of native American mtDNA than nuclear genes to Hispanic populations (Merriwether et al. 1997), which supports our results indicating a greater contribution of European-American males than females to the Hispanic gene pool.

Sufficient information does exist, however, to permit estimates of the European-American genetic contribution to African-Americans. Previous studies based on nuclear loci have generally found ~20% European genetic contribution to African-American populations (Reed 1969; Chakraborty et al. 1992; Parra et al. 1998; Destro-Bisol et al. 1999; Collins-Schramm et al. 2002), in agreement with our estimate (averaged for mtDNA and the Y-chromosome) of 18%-24%. Our results indicate substantially higher contribution of European-American Y-chromosome (27.5%-33.6%) than mtDNA (9.0%-15.4%) to African-Americans, also in agreement with previous studies (Parra et al. 1998, 2001). Presumably, this disparity in admixture estimates for the Y-chromosome versus mtDNA reflects the greater genetic contribution of European-American men than women to African-Americans during the slavery period. However, there is currently an increasing trend toward more marriages between African-American men and European-American women; census data indicate that in 1960 there were 25,000 marriages involving African-American men and European-American women and 26,000 marriages involving African-American women and European-American men, whereas in 1992, there were 163,000 marriages involving African-American men and European-American women and 83,000 marriages involving African-American women and European-American men (source, U.S. Census Bureau, http://www.census.gov/population/socdemo/race/interractab1.txt). In our study, on the basis of self-reported ancestry, the offspring of marriages between African-Americans and European-Americans would generally be assigned as African-Americans rather than European-Americans. Hence, if this trend continues, the disparity between mtDNA and Y-chromosome-based estimates of the European genetic contribution to African-Americans may eventually diminish or even reverse direction. (This also doesn't count the majority of sexual unions with black men and white women out of wedlock (70% of black men father children out of wedlock). Thus the number of mulatto children by white women is far greater than estimated.)

Gesta Bellica
Wednesday, February 18th, 2004, 07:32 AM
Important excerpts:

The African-American genetic contribution to European-Americans is below the limits of detection with these methods. (In other words, practically non-existent. I suppose this may be different with other DNA studies because of the specific isolation of European-Americans, rather than the more ambiguous "white" group. The latter may include individuals of recent non-white admixture yet still call themselves white and non-Europeans who may have more admixture.)


European-American genetic contribution to African-Americans (Table 5) was much higher for the Y-chromosome than for mtDNA; ~27.5%-33.6% of African-American Y-chromosomes were determined to be of European-American ancestry versus only 9.0%-15.4% of African-American mtDNAs.

We found no significant heterogeneity among regional groups of African-Americans, which seems somewhat surprising for two reasons. First, a large number of different African source populations contributed to present-day African-American groups, with about half coming from the area extending from Senegal to Western Nigeria, and the remaining half coming from the area extending from Eastern Nigeria to Angola (Curtin 1969; Reed 1969). However, the amount of genetic heterogeneity among these West and Central African source populations that contributed to African-Americans is not known, as a comprehensive study of genetic variation in these populations has not been carried out.

Second, the amount of admixture of African-Americans with European-Americans is thought to have varied across different geographic regions of the U.S., with generally higher levels of admixture observed in Northern groups (Reed 1969; Chakraborty et al. 1992).

A further complicating factor is migration among geographic regions within the United States. Even with heterogeneity in the founding West African populations and/or the subsequent amount of European-American genetic contribution to African-Americans, migration of African-Americans within the United States may have been extensive enough to eliminate between-group differences in Y-STR haplotype frequencies. In particular, during and following World War I, an estimated one million African-Americans (~10% of the African-American population) left rural areas in the southern United States for metropolitan areas in the north (Johnson and Campbell 1981; Tanner 1995). The lack of geographic heterogeneity observed in African-American mtDNA and Y-chromosome types may thus reflect this "Great Migration", the largest internal migration in the history of North America.

The overall lack of geographic heterogeneity among European-Americans is not surprising, as European populations exhibit little differentiation with respect to Y-STR haplotypes (Roewer et al. 2001) and mtDNA types (Melton et al. 1997b). However, the striking uniformity among regional groups of Hispanics for both Y-STR haplotypes and mtDNA types (see Fig. 4) is surprising, given that Hispanic does not refer to a defined geographic region, in contrast to European-American and African-American. Instead, the ethnic category, Hispanic, typically can refer to someone of Mexican, Puerto Rican, Cuban, Central/South American, or other Spanish culture ancestry (Chakraborty et al. 1999), and previous analyses have estimated varying degrees of native American, Spanish, and African ancestry in Hispanic populations (Hanis et al. 1991; Merriwether et al. 1997; Chakraborty et al. 1999).

For the mtDNA SSO-types, the Hispanic and European-American groups were completely separated from one another (Fig. 4), whereas for the Y-STR haplotypes, there was some intermingling of Hispanic and European-American groups.

It appears that the paternal and maternal structure of Hispanic groups differ, most likely reflecting a greater contribution of European-American Y-chromosomes than mtDNA haplotypes to the Hispanic gene pool. Although insufficient data from potential source populations among native North American, Central American, and Caribbean populations exist to permit estimates of admixture for Hispanic groups on the basis of Y-STR haplotypes or mtDNA SSO-types, other studies have found a greater contribution of native American mtDNA than nuclear genes to Hispanic populations (Merriwether et al. 1997), which supports our results indicating a greater contribution of European-American males than females to the Hispanic gene pool.

Sufficient information does exist, however, to permit estimates of the European-American genetic contribution to African-Americans. Previous studies based on nuclear loci have generally found ~20% European genetic contribution to African-American populations (Reed 1969; Chakraborty et al. 1992; Parra et al. 1998; Destro-Bisol et al. 1999; Collins-Schramm et al. 2002), in agreement with our estimate (averaged for mtDNA and the Y-chromosome) of 18%-24%. Our results indicate substantially higher contribution of European-American Y-chromosome (27.5%-33.6%) than mtDNA (9.0%-15.4%) to African-Americans, also in agreement with previous studies (Parra et al. 1998, 2001). Presumably, this disparity in admixture estimates for the Y-chromosome versus mtDNA reflects the greater genetic contribution of European-American men than women to African-Americans during the slavery period. However, there is currently an increasing trend toward more marriages between African-American men and European-American women; census data indicate that in 1960 there were 25,000 marriages involving African-American men and European-American women and 26,000 marriages involving African-American women and European-American men, whereas in 1992, there were 163,000 marriages involving African-American men and European-American women and 83,000 marriages involving African-American women and European-American men (source, U.S. Census Bureau, http://www.census.gov/population/socdemo/race/interractab1.txt). In our study, on the basis of self-reported ancestry, the offspring of marriages between African-Americans and European-Americans would generally be assigned as African-Americans rather than European-Americans. Hence, if this trend continues, the disparity between mtDNA and Y-chromosome-based estimates of the European genetic contribution to African-Americans may eventually diminish or even reverse direction. (This also doesn't count the majority of sexual unions with black men and white women out of wedlock (70% of black men father children out of wedlock). Thus the number of mulatto children by white women is far greater than estimated.)

Interesting.
So we can say that the racial purity of american whites has been preserved also with the epuration fo the non whites mongrels from their society?
Otherwise why the contributions between the different ethnicities would be so different?
Not that i am against it, au contraire, i think it would be the only solution if we would start a racial state tomorrow.