ABSTRACT
This chapter discusses the role that natural selection within the American continent may have played on the characteristics of Africanized bees at different phases of colonization. The rapid colonization of tropical America by Africanized bees is thought to be the result of long distance swarm movement, aided by a short generation time, and absconding. During the colonization of a new geographic area of suitable habitat from a single point of introduction, such as tropical America, consistent orientations will be continually selected for during the colonization process. In particular, colonization will select for dispersal away from the point of introduction, and away from the colonizing front. The chapter describes the idea proposed by D. J. C. Fletcher, that natural selection at the colonizing front leads to selection for traits that increase colonizing ability and contrast this with natural selection behind the colonizing front.
