My curiosity was how could it be type O as 99% of South America, yet very diluted in the so called origin of man?
I am sure they have had Mosquitoes and Malaria since the beginning of time in the old world and the far east.
Logic would dictate it should be the other way around right? If man came from Africa, Asia, and then east to the new world?
Logic is type O originated from South America and then spread west... But that opens another door...
Well, chromosome 9 has our primary bloodtype coding.
Type A and Type B differ by I think it is 16 base pairs.
Type O is otherwise identical with Type A, but missing the first base pair.
Given that A is as common as O, and B appears to be an isolate mutation of A from a long time ago, it’s apparent that O is older than B but younger than A.
Ah, here it is:
[snip] The ABO gene codes for an enzyme called galactosyl transferase and determines your blood group. In people with A and B blood groups, the gene differs by seven basepairs, four of which have an effect on the type, shape and activity of the enzyme. People with O blood group have a single deletion in the gene that causes an inactive protein to be made.[/snip]
https://dnalc.cshl.edu/view/15404-Chromosome-9-gene-for-blood-group-Matt-Ridley.html