No. Sickle cell genes originated in Africa but then they spread to other groups including Southern Europe as well.. This example underscores the importance of looking at populations rather than the old racial groups. The people that happened to originate this trait happened to have black skin. However, that says nothing about all the many other groups of people with black skin that never got this trait. It was a black-skinned population, not the whole black “race” that got it. The people that originated this trait later passed it on to other groups that did not have black skin.
The sickle cell trait originated in people that have black skin.
However, other groups with black skin do not have it.
The trait was passed on to other populations that do not have black skin
Do you see the difference? Traits can still be rather localized and that still says nothing about the races.
Harmonious, this is wrong on so many levels that I am not sure where to begin. But in the interest of fighting ignorance, begin I must.
Firstly Sickle Cell Disease does NOT occur only in black people. They have it more commonly than others, but it is seen in many other populations.
Secondly, it does not protect against sleeping sickness. Having one copy of the Sickle gene is somewhat protective against malaria.
Thirdly, not all the red blood cells in a patient with sickle cell are sickle shaped. Most of the time, most of the red cells of a sickler look just like other people’s cells. But when the oxygen tension drops too low, or the person is stressed, a greater percentage of the red cells sickle, causing problems. But at no time are all the cells sickle-shaped.
Fourthly, There are NO GENETIC differences in races that do not show up in other races. I’ve seen black-skinned people with cystic fibrosis, people of mediterranian ancestry with sickle-cell, and french-canadians with Tay-Sachs.
Sickle cell trait is much more common in those of West African ancestry, but it is by no means restricted to them.
Sickle cell trait (given by a single copy of the Sickle cell allele) gives resistance to malaria, not Sleeping Sickness.
Name one. There are genetic characteristics of certain populations that are largely restricted to those populations. There are few if any genetic characteristics that are possessed by all or most of the members of a particular traditional “race” but which do not show up in other “races>”
Sickle cell is one of two variants of a disorder that occurs throughout much (but not all) of Africa and several European and Middle Eastern regions populated by “Caucasian” peoples and does not affect a large number of people in Southern Africa where the incidece of malaria is low. In the Middle East, a variation in the alleles occurs so that the same basic condition contiues Eastward all the way acorss Northern India.
Sickle Cell is endemic to such “white” populations as Maltese, people in the toe and heel of Italy, Greece, Turkey, and Lebanon.
Its prevalence in blacks in the U.S. is due to the fact that the overwhelming number of slaves imported to the U.S. were imported from malarial regions of West Central Africa. It is lesser known among whites because fewer whites have immigrated from Malta and the regions of Italy and Greece where it is endemic.
And all four of you twacked at it with the Sledgehammer of Knowledge like a well-honed railroad crew. Ignorance, in this case, didn’t stand–if you’ll pardon the expression–a chinaman’s chance of enduring. Very .
That’s exactly what I meant. I didn’t know if the recessive gene for sickle cell also conferred any resistance to the tsetse fly disease.
From your link:
“A second well-documented example of a nonspecific factor involved in resistance is the presence in the serum of humans of a trypanolytic factor that confers resistance against Trypanosoma brucei brucei, an agent of trypanosomiasis (sleeping sickness) in animals.”
So, it’s a factor other than the recessive SC gene.
The fight against my ignorance just won another skirmish.
The most valuable thing I’ve learned since my sojourn on the SDMB is that there is no such thing as race. It has allowed me to see beyond colour. The fact that there is more genetic diversity within the black population of Africa than among the rest of the “races” clearly shows to me that black people in Africa as a whole have a much greater variety of genetic heritages developed one hundred plus thousand years ago than the limited number of genetic lines that managed to exit Africa 40 t0 60 thousand years ago.
While the rest of the world outside Africa were faced with climatic and geographical novelties that affected their external features, in most cases the skin colour of Africans remained constant.
If one is determined to hold on to the concept of race, than I would say that there are many races that are black. In that case we are talking about populations.
The vast majority of black Americans can trace a ancestry to West Africa. This perception of black superiority up till recently has been the American experience of having 10 % of their population which is visibly black showing a clear superiority at the elite levels of popular American sports. Explanations such as selection through slavery are ridiculous. Ascribing a common superiority among all black Americans is ridiculous. But if we accept the evidence that superior athletes in the running and jumping sports are endowed with a greater amount of fast twitch muscle fibers then we are left with two questions if we want to explain this.
Is the reason cultural or natural.
Can fast twitch muscles be developed to the point where a Kenyan can participate in the 100m olympic event?
I guess that’s another thing the schools thought you that were wrong item. I just found out they lied about single cell organisms never reproducing sexually either.
Your question does not mention race, ethnicity, populations, etc. It’s easy enough to sidestep those issues by rephrasing the question:
Is there a biologicial difference in blacks that makes blacks faster in the same sense that blacks respond differently to BiDiL?
Although I am not aware of any scientific studies on this issue, common sense indicates that the answer is probably yes. It’s the simplest explanation for the dominance that certain blacks enjoy both within the US and around the world in sports that emphasize speed.
How does “common sense” explain the dominance of blacks in many other sports that do not emphasize sprinting speed, such as basketball or heavyweight boxing? Just how many genes are we talking about here? How does it explain the fact the dominance in sprinting is shown mainly by those of West African ancestry from developed countries, not by West Africans themselves?
The simplest explanation that fits most of the facts is that economic, social, and cultural factors play a very large role in the dominance of particular ethnic groups in particular sports. While there may be some physical differences between populations that may provide an edge in some restricted areas, these hardly provide a general explanation.
What does it matter? I’m certainly not claiming that all perceived differences between blacks and whites are biological in origin.
I have no idea. However, it is not necessary to point to a particular gene or chromosone to conclude that a difference is biological.
I think that Frank Fredericks (born in Namibia) and Francis Obikwelu (born in Nigeria) might have something to say about that. Each has among the top 10 100 meter dash times in history.
I doubt that anyone would claim that all differences are biological in origin.
So why, exactly, should the dominance of blacks in sprinting be due biological factors if dominance in other sports is not? The evidence for an actual biological basis is very thin; there are a large number of assumptions involved that have not been tested.
However, one would like to have much stronger evidence than that currently available to reach such a conclusion.
If you mean evidence coming from scientific studies, I would guess that you are right. However, I doubt there is much of this sort of evidence either way.
I believe that many animal conditions and differences were (and are) strongly believed to be biological in origin before the underlying mechanisms were (and have been) discovered.
You indicated that you thought the “common sense” answer was that there were probably biological differences. I would say that given that most sports have been dominated by widely different ethnic groups during their history; that blacks currently dominate a wide variety of sports, many of which do not demand the same kind of physical aptitudes (or which demand a variety of different aptitudes), and that blacks constitute a very genetically heterogeneous population, that this is not a likely to be general explanation. Based on this, the “common sense” position would be that the differences are non-biological.
