Question

A variant of a gene that plays a role in infection with the lassa virus occurs in 34% of people in nigeria, where the virus is prevalent, but in nobody outside of west africa. which of the following statements is true?

a. the nigerian variant is harmful to individuals living outside of west africa
b. the nigerian variant is favored by natural selection only in geographic areas where the lassa virus is common
c. the variant found in nigerians increases the rate of infection with the lassa virus
d. individuals living outside of west africa are immune to the lassa virus

Answer 1

The true statement is that the Nigerian gene variant associated with the Lassa virus infection is favored by natural selection only in areas where the Lassa virus is common, which helps explain its regional prevalence.

Step-by-step explanation:

The correct statement regarding the variant of a gene associated with the Lassa virus infection in Nigeria is that the Nigerian variant is favored by natural selection only in geographic areas where the virus is common. This pattern aligns with Charles Darwin's theory of evolution by natural selection, which explains that beneficial genetic traits tend to increase in frequency in populations where they provide a survival advantage. In this case, the gene variant may confer some protective effect against the Lassa virus, which is prevalent in West Africa, thus providing a selective advantage to those who carry it in that region. However, this advantage is not necessarily conferred to individuals outside of West Africa, where the virus is not a common threat, making the presence of this gene variant less likely. Therefore, statement B is the true statement.