why are black people resistant to malarial infections? what are the scientific reason?
- Anonymous1 decade agoFavorite Answer
I read that many Blacks are heterozygous for the sickle cell gene, i.e., only one chromosome carries it. This means that they have the sickle cell gene, but they don't get sickle cell anemia. As I understand it, sickle cell anemia is a recessive trait, so one must be homozygous for this trait for the person to actually have sickle cell anemia, i.e., one must have two chromosomes that carry the gene.
The sickle cell gene appears to confer immunity from malaria upon one who carries it--regardless of whether the person is heterozygous or homozygous for the trait.Source(s): Some college Genetics and Biochemistry courses I took long ago.
- KokopelliLv 71 decade ago
If this is indeed fact, then it might be selective adaptation. Assuming that in the past many black people lived in areas that had a higher incidence of malaria, expaosure over hundreds of years would have tended to kill off the ones with lesser immunity to the disease, leaving alive only the ones better able to tolerate it.
For the same reason it is not such a good idea to protect a newborn baby from dirt. Infants who get to crawl around in dirt develop a better resisitance to disease by being exposed to it from the beginning. People who insist on having a spotlessly clean home and leave their shoes outside will find their kids have more (and more severe) childhood diseases later on.Source(s): No animals or plants were harmed in the answering of this question. Any similarity with any person, living or dead, is purely coincidental and unintended. This answer contains a substance known by the state of California to cause excessive moronic stupidity. Use with adequate ventilation.
- 1 decade ago
Long term exposure to certain diseases made them more resistant. It is similiar to how Indians lost 90% of their population to disease when the Europeans first arrive at the turn of the 15th Century in America. They had no immunity to these new diseases. People in Europe still died of disease such as measles, but had immunities to other diseases that helped fight this one off. Isolation from the rest of the world left them with little or no resistance to these pathogens. Not all "black" people, but some people of African descent were exposed to malaria and similiar diseases often and formed a resistance that was passed on. Given enough time, these resistances will where down if they are no longer exposed
- curiousgeorgeLv 51 decade ago
Some black people have a helpful mutant gene which is referred to as sickle cell trait. The sickle cell trait is helpful in that it offers a natural resistance to malaria. The people with 2 mutant genes of this type actually have sickle cell anemia which is not a good thing.
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- 1 decade ago
They are only resistant if they have the sickle-cell trait. Believe me, millions of Africans die every year from malaria.
Complicated genetics aside, if you inherit a sickle-cell gene from BOTH your parents, you will have sickle-cell anemia and die and/or have a rought life. If you inherit only ONE gene, then you have sickle-cell trait, which provided protection from malaria.
- Anonymous1 decade ago
Only those with the sickle cell gene. This disease affords some protectiion because of the abnormal hemoglobin.
- Ya-saiLv 71 decade ago
First, who are black people and second can you give me proof that these 'black people' (whoever they are) have this resistance.