THE GENETIC CONSEQUENCES OF LONG-DISTANCE DISPERSAL DURING COLONIZATION

Rare long distance dispersal may have little impact on gene frequencie s in established populations but it can dramatically increase gene flo w during episodes of range expansion. We model the invasion of new ter ritory by genetically distinct populations of the same species to inve stigate the dynamics of such episodes. If long distance dispersal is s ufficiently frequent, the populations do not spread as a wave of advan ce but instead found intermingled isolates. We argue that this process can explain many otherwise puzzling patterns in the geographical dist ribution of alleles.