Question

Two observations can be made regarding this study; The lap^94 allele helps mussels maintain osmotic balance in water with a high salt concentration, but it is costly to use in less salty water. Mussels produce larvae that can disperse long distances before they settle on rocks and grow into adults. What hypothesis would explain the patterns in the data?
a. The frequency of the lap^94 allele at different sites results from an interaction between selection and genetic drift. b. The frequency of the lap^94 allele at different sites results from an interaction between selection and gene flow.
c. The frequency of the lap^94 allele at different sites results from the effects of selection.
d. The frequency of the lap^94 allele at different sites results from the effects of gene flow.

Answer 1

Answer:

b. The frequency of the lap94 allele at different sites results from an interaction between selection and gene flow.

Explanation:

In the southwest portion of the Sound, salinity is relatively low, and selection against the lap94 allele is strong. Moving toward the northeast and into the open ocean, where salinity is relatively high, selection favors a high frequency of the lap94 allele. However, because mussel larvae disperse long distances, gene flow prevents the lap94 allele from becoming fixed in the open ocean or from declining to zero in the southwestern portion of Long Island Sound.