How do island model and stepping-stone or isolation-by-distance population structures differ in their effects on genetic differentiation?

• A. Isolation-by-distance leads to clinal variation with differentiation increasing with distance; stepping-stone yields more localized differentiation; both produce spatial autocorrelation of allele frequencies.
• B. Island model and stepping-stone yield identical patterns of differentiation.
• C. Stepping-stone yields panmixia.
• D. Island model yields no differentiation.

Answer: (A)