allelic frequency

This is from a discussion of genotype variation in the biology class that I have been taking. Today was the last day of the class. I didn't expect to feel this way but I'm kind of sorry its over. The subject matter was actually starting to become interesting to me.

The allelic frequencies in a population such as the US will have greater shifts than a country such as China due to the greater range of genetic variation. Persons of various racial backgrounds reside in a country such as the United States whereas a country such as China is reasonably homogenous for phenotype and thus presumably also fairly homogenous in it range of genotypes. If there were an influx of immigrants of other racial types to China over the next 25 years, there would be new alleles introduced into the offspring of couples of mixed racial types. This would cause a greater variation in alleles.