Increase in island distance primarily affects:
“Immigration rate” for increase in island distance primarily affects. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. Larger islands usually support more habitats and larger populations, lowering extinction risk; less isolated islands receive colonists more readily and may experience rescue effects. These mechanisms also apply to habitat fragments that function as ecological islands. The remaining alternatives—“Extinction rate”, “Resource availability”, “Genetic drift”—refer to different states, p
Ref: Biogeography, Lomolino et al., 5th Ed., Ch. 5-8