Posted: Sun 01 Jul 2007 01:12 Post subject: Re: Latin Americans That Look Indistinguishable In Phenotype
fwsweet wrote:
For example, in Puerto Rico, Afro-Euro admixture is pretty close to 50-50. So about one island native in eight looks subsaharan (like the photos), about one in eight looks northern European (like me), and the rest are somewhere in between.
Not sure about that Frank. Quoting an old post of mine (carpal tunnel, you know): Most Puerto Ricans have European, Taino and then African Ancestry. In that order of prevalence. What is interesting is that in Puerto Rico it was just assumed they were all mulattos in ancestry and most just called themselves White. An after effect of patriarchism. Most descend from European and African male ancestors with a small contribution of Amerindians. So it was assumed Black or White or both. But genetic studies have shown that in female ancestry Europeans and Tainos completely flip flop. When you add male and female contribution together, Tainos come second instead of third.
The population of Puerto Rico revealed mitochondrial maternal ancestries in this highly mixed population of 61.3% Amerindian, 27.2% sub-Saharan African, and 11.5% European." A preliminary study of the Y chromosome showed the opposite in the paternal line: Most islanders are descended from European forefathers 70%, with African heritage 20% coming in second and American Indian 10% third.
Combining these two studies gives us a rough idea of Puerto Rican admixture overall (unless someone has conducted a large sampling ala AncestrybyDNA):
A guesstimate of 41% European, 36% Amerindian, 24% African admixture.
That would not be 50/50. And that would throw off your statistics based of a 50/50 premise.
Joined: 29 Jun 2007 {Posts: 10 } Location: Big Town
Posted: Sun 01 Jul 2007 01:21 Post subject:
fwsweet, we can agree that we both made the numbers up. We both speculated according to what little information we know based on phenotype of these locations and demographics. There is no numerical anthropological data on regions, there is demographic census though.
I'm from Anthro forums and when someone says let's say a "Nordic" or "western SSA" phenotype I'm sure will be having something else in mind.
PR have 3 components, pred.Iberian, Taino and western SSA which is also backed by DNA data. Of course you can also observe the phenotypical components upon observing each individual respectively.
Posted: Sun 01 Jul 2007 01:35 Post subject: Re: Latin Americans That Look Indistinguishable In Phenotype
Salsassin wrote:
The population of Puerto Rico revealed mitochondrial maternal ancestries in this highly mixed population of 61.3% Amerindian, 27.2% sub-Saharan African, and 11.5% European." A preliminary study of the Y chromosome showed the opposite in the paternal line: Most islanders are descended from European forefathers 70%, with African heritage 20% coming in second and American Indian 10% third.
I assume that your mtDNA numbers come from the Martinez-Cruzado study (he died recently, by the way). Where do the Y numbers come from?
Salsassin wrote:
Combining these two studies gives us a rough idea of Puerto Rican admixture overall (unless someone has conducted a large sampling ala AncestrybyDNA)
No. At least no one has published one yet, although Shriver said that he was working on one the last time that I talked to him.
Salsassin wrote:
A guesstimate of 41% European, 36% Amerindian, 24% African admixture. That would not be 50/50. And that would throw off your statistics based of a 50/50 premise
That is true. Your estimate would reduce the Afro phenotype to about 2 percent, based on my simulator at http://backintyme.com/admixture/genetics.xls. But, ignoring Amerind, your mtDNA numbers shows twice as much Afro as Euro (33-67) and your Y numbers show three times as much Euro as Afro (75-25). If you split the difference between mtDNA and Y, then using your numbers you get 55-45 Euro-Afro, which yields 7 percent Afro phenotype.
Again, though, without autosomal tests, we are just groping in the dark. That is why I use census data.
Posted: Sun 01 Jul 2007 01:44 Post subject: Re: Latin Americans That Look Indistinguishable In Phenotype
fwsweet wrote:
Salsassin wrote:
The population of Puerto Rico revealed mitochondrial maternal ancestries in this highly mixed population of 61.3% Amerindian, 27.2% sub-Saharan African, and 11.5% European." A preliminary study of the Y chromosome showed the opposite in the paternal line: Most islanders are descended from European forefathers 70%, with African heritage 20% coming in second and American Indian 10% third.
I assume that your mtDNA numbers come from the Martinez-Cruzado study (he died recently, by the way). Where do the Y numbers come from?
Salsassin wrote:
Combining these two studies gives us a rough idea of Puerto Rican admixture overall (unless someone has conducted a large sampling ala AncestrybyDNA)
No. At least no one has published one yet, although Shriver said that he was working on one the last time that I talked to him.
Salsassin wrote:
A guesstimate of 41% European, 36% Amerindian, 24% African admixture. That would not be 50/50. And that would throw off your statistics based of a 50/50 premise
That is true. Your estimate would reduce the Afro phenotype to about 2 percent, based on my simulator at http://backintyme.com/admixture/genetics.xls. But, ignoring Amerind, your mtDNA numbers shows twice as much Afro as Euro (33-67) and your Y numbers show three times as much Euro as Afro (75-25). If you split the difference between mtDNA and Y, then using your numbers you get 55-45 Euro-Afro, which yields 7 percent Afro phenotype.
Again, though, without autosomal tests, we are just groping in the dark. That is why I use census data.
By comparing census data to the statistics above are we talking about the same things. Are we saying that 24% of Puerto Ricans are African, or are we saying that the average Puerto Rican (whatever that means) is about one quarter African?
fwsweet, we can agree that we both made the numbers up.
I am happy to agree that you made your numbers up. On the other hand, I have twice provided the sources for my numbers. Read the material I provided or not, as you see fit. But please do not opine further on the subject unless you are willing to back up your claims.
Please understand. The issue is not who is right or wrong, nor whose estimate is better. The issue is that I have explained how I computed my estimates, and the sources from which I drew. This enables us to discuss my estimates, to question their data and methodology (as you can see from my exchange with Jaime). You, on the other hand, have made no attempt to back up your claim. Since we have no idea where you got your numbers from, there is no way that we can discuss them.
ShadowMassa wrote:
I'm from Anthro forums and when someone says let's say a "Nordic" or "western SSA" phenotype I'm sure will be having something else in mind.
Perhaps. But the most important difference between this forum and others is that we demand sources for every statement of fact. Please read The Rules.
Last edited by fwsweet on Sun 01 Jul 2007 02:06; edited 1 time in total
Posted: Sun 01 Jul 2007 02:04 Post subject: Re: Latin Americans That Look Indistinguishable In Phenotype
caribj wrote:
By comparing census data to the statistics above are we talking about the same things. Are we saying that 24% of Puerto Ricans are African, or are we saying that the average Puerto Rican (whatever that means) is about one quarter African?
Given that PR lacks an endogamous barrier, then the distribution is Gaussian (normal, unimodal). Given this:
If we use my 50-50 estimate, then the (mean) average SSA admixture is 50 percent, but only 12 percent of individuals look African (to USAmericans--see the article. Other folks have different perceptions).
If we use the 55-45, then the mean SSA admixture is 45 percent but only 7 percent of the people look Afro (again, to USAmericans).
If we use Jaime's 41-24, then the mean SSA admixture would be 37 percent (ignoring Amerind) but only 2 percent of them would look Afro.
In short, the number who look distinctly African drops off pretty steeply as the mean admixture falls below 40 percent. That is why virtually no Argentinean looks African, despite the 6.5 percent mean admixture.
Joined: 29 Jun 2007 {Posts: 10 } Location: Big Town
Posted: Sun 01 Jul 2007 02:15 Post subject:
Quote:
For 1792, see Francisco Morales Padron, “La Vida Cotidiana en una Hacienda de Esclavos,” Revista del Instituto de Cultura Puertorriquena, 4 (no. 10, 1961), 23-33, 25. For a census-by-census table of subsequent years, see Frederick P. Bowser, “Colonial Spanish America,” in Neither Slave Nor Free: The Freedmen of African Descent in the Slave Societies of the New World, ed. David W. Cohen and Jack P. Greene (Baltimore, 1972), 19-58, 38.
Okay, this data isn't anthropological correct ? It is difficult to located data on phenotypes based numerically per region or nation. Demographic census is a different story.
However, reading the rest of your input I now understand what you mean.
Speaking of PR's from my perspective and observation. U.S PR's tend to appear either Trihybrid, Castizo-Mestizo, Mulato, Quandroon and Mediterranean.
The question here percentage that can pass for a Sub Saharan African rather than Black to U.S Americans. Any number on that "fwsweet" ?
Posted: Sun 01 Jul 2007 02:40 Post subject: Re: Latin Americans That Look Indistinguishable In Phenotype
fwsweet wrote:
Salsassin wrote:
The population of Puerto Rico revealed mitochondrial maternal ancestries in this highly mixed population of 61.3% Amerindian, 27.2% sub-Saharan African, and 11.5% European." A preliminary study of the Y chromosome showed the opposite in the paternal line: Most islanders are descended from European forefathers 70%, with African heritage 20% coming in second and American Indian 10% third.
I assume that your mtDNA numbers come from the Martinez-Cruzado study (he died recently, by the way). Where do the Y numbers come from?
Unfortunately, it came up in my dealings with the Cruzado study a long time ago and I have not been able to locate it's source. Yeah, I remeber he died before he could complete his DR. study.
Quote:
No. At least no one has published one yet, although Shriver said that he was working on one the last time that I talked to him.
Cool.
Quote:
That is true. Your estimate would reduce the Afro phenotype to about 2 percent, based on my simulator at http://backintyme.com/admixture/genetics.xls. But, ignoring Amerind, your mtDNA numbers shows twice as much Afro as Euro (33-67) and your Y numbers show three times as much Euro as Afro (75-25). If you split the difference between mtDNA and Y, then using your numbers you get 55-45 Euro-Afro, which yields 7 percent Afro phenotype.
Again, though, without autosomal tests, we are just groping in the dark. That is why I use census data.
Right. But the census can be lopsided as well as the subjectiveness of what is white or black affects the stats.
The question here percentage that can pass for a Sub Saharan African rather than Black to U.S Americans. Any number on that "fwsweet"?
No. Harry Hoetink wrote some comparative stuff about how the "somatic norm image" varies from one place to the next. How the same person, for example, would be seen as White in Santo Domingo, trigueno or mixed in PR, but Black in the United States, but he never really quantified it.
Since my field of study is the United States, I am lucky that analyzing just what traits say "Black" to USAmericans was a popular task among physical anthropologists in the 1930s. I rely heavily on work done at that time, especially by Caroline Bond Day and Earnest Albert Hooton, A Study of Some Negro-White Families in the United States (Cambridge MA: Harvard University, 1932) and Melville J. Herskovits, The Anthropometry of the American Negro (New York: Columbia University, 1930). On the basis of their findings, anyone with less SSA admixture than 85-15 (Euro-Afro) looks White to Americans. And anyone with more SSA than 15-85 (Euro-Afro) looks native African to Americans. So those are the numbers that I use to predict, for example, how many (phenotypically) White kids will be born into a Black community.
The good news is that Day, Herskovitz, and Hooton were from different regions, so they took into account regional differences in perception. The bad news is that they related everything to genetic admixture (which they called "Negro blood") and, as we all know, there can be a mismatch between external racialized traits and historical ancestry due to random recombination in meiosis at each generation.
I almost forgot. There was a study by G.A. Harrison and J.J.T. Owen, “Studies on the Inheritance of Human Skin Colour,” Ann. Human Genetics 28 (1964) that looked at overall perception of "race" as well as mere skin tone. But it was done on African and West Indian immigrants in Liverpool, so it reflects Brit rather than U.S. perceptions. (The difference being that Americans see a dichotomy while Brits see three groups.)
Joined: 30 Mar 2005 {Posts: 1057 } Location: New Jersey
Posted: Tue 10 Jul 2007 20:29 Post subject:
Frank wrote:
For example, in Puerto Rico, Afro-Euro admixture is pretty close to 50-50. So about one island native in eight looks subsaharan (like the photos), about one in eight looks northern European (like me), and the rest are somewhere in between.
When I look at books or travel programs on Puerto Rico, I tend to see quite a lot of people who look European to me. But you did say one in eight looks northern European -- so if one included the various European Mediterranean Basin phenotypes in the "white" category, maybe it would be considerably larger. Perhaps in the skin-tone chart in your Heredity of Racial Traits essay it would include the slightly gray bar next to the white bar, and possibly a part of the next, slightly darker bar.
'
FAQ
Search
Register
Log in
