Sickle Cell protects against malaria. As awful as it is, it persists because your survival with sickle cell was better with it than without it in some regions where malaria was a big issue. (Granted, it may be a case where having one copy of the gene is a good thing with minimal downside and two copies is "Damn, that suuuucks." But the mutation persists for a compelling survival reason and not actually because the butthead in charge of the universe is simply a sadistic jackass like I so often feel they are.)
Probably most major "genetic disorders" are adaptive to some degree and in some manner. And most drugs have significant side effects. If "tan in a pill" causes heart attacks or cuts off circulation to your toes such that they necrotize and fall off, welp, you can keep your damn "tan in a pill" as far as my pale ass is concerned.
Sickle cell trait (being heterozygous for the gene that replaces beta-globin with hemoglobin S) protects against anemia, and does not, in and of itself, produce sickle cell disease.
> As awful as it is, it persists because your survival with sickle cell was better with it than without it in some regions where malaria was a big issue.
It persists because being heterozygous for the sickle cell gene makes you much more likely to survive and reproduce where malaria is widespread. Actual sick cell disease, whether being homozygous for hemoglobin S (sickle cell anemia) or having some other defect on the other copy of the HBB gene while also having the sickle cell trait, IIRC, isn't a net advantage, even there.
Yes, I did try to make that distinction. Sorry I wasn't clearer.
At the individual level, having two copies of the gene is hell to pay. At the group survival level, the existence of the mutation is protective of group survival.
Exactly.
Sickle Cell protects against malaria. As awful as it is, it persists because your survival with sickle cell was better with it than without it in some regions where malaria was a big issue. (Granted, it may be a case where having one copy of the gene is a good thing with minimal downside and two copies is "Damn, that suuuucks." But the mutation persists for a compelling survival reason and not actually because the butthead in charge of the universe is simply a sadistic jackass like I so often feel they are.)
Probably most major "genetic disorders" are adaptive to some degree and in some manner. And most drugs have significant side effects. If "tan in a pill" causes heart attacks or cuts off circulation to your toes such that they necrotize and fall off, welp, you can keep your damn "tan in a pill" as far as my pale ass is concerned.