The O allele is unusually frequent in the Americas. What does this pattern suggest about the evolutionary history of these populations?

Populations from the Americas started from a founding population with a high frequency of the O allele

Explanation:

Human blood type is determined by three different codominant alleles: IA, IB, and, which are named A (IA), B (IB), and O (i). Each person has two blood type alleles, i.e., one allele inherited from the mother and one from the father. The frequency of the O blood allele is very high in indigenous populations, and in Central and South American populations this allele may reach a frequency of 1 (100%). In consequence, the predominance of the O blood allele in Native American populations suggests that these populations descended from a founding population that had a high frequency of the O blood allele. A founder effect may even cause the fixation of one allele within a population, and this phenomenon is known to be associated with the loss of genetic variation.

a: the sheep and waste material both release carbon into the atmosphere.

sand 60

clay 10

silt 30

sandy loam should be dominated by the sand. as the amount of sand increased, the amount of slit needed to anchor the plants' roots to the sand will also be increased. even though the amount is very little, 10% part of clay is still necessary for proper oxidation.