For many generations, the following genotypic frequencies were observed in a large population of dinosaurs: 4 percent aa, 32 percent aa, and 64 percent aa. the climate changed abruptly and resulted in the death of all homozygous recessive dinosaurs (s = 1). in the next generation, the recessive homozygotes died shortly after birth. what percentage of these newborn dinosaurs died? show calculation
a) 4% b) 8.5% c) 19.7% d) 36.8% e) 44%

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?