The presence of three alleles I the ABO blood grouping system is an example of

as resources become scarce because of population growth, the growth decreases after few years due to lack of resources and food.

this age may represent the age of the earth's accretion, of core formation, or of the material from which the earth formed. this dating is based on evidence from radiometric age-dating of meteorite material and is consistent with the radiometric ages of the oldest-known terrestrial and lunar samples.

if you know your abc's you should be able to get your answer or just use google