If the allele for an attached earlobe (e) is recessive to the allele for an unattached earlobe (E), what will be the relative frequency of e in a population? It could only be more frequent than E. It could be more or less frequent than T. It could only be equally as frequent as T. It could only be less frequent than T.

Astudy by solloch and et. al., in 2017, gives the map above which shows the frequency of alleles with a ccr5-delta32 mutations over 87 different countries. this mutation deletes the presence of a co-receptor (ccr5) on the outside of human t-cells (lymphocytes). some viruses, such as the one responsible for the black death and human immunodeficiency virus (hiv), require this receptor for attachment to host cells during the infection process. the black death was an epidemic that passed over northern europe during the 14th century killing nearly 60% of europeans. according to this information, which explanation best explains why northern europeans show a greater immunity for hiv than some other parts of the world?