Distribution Patterns of Insects in Tropical Habitats

Abstract

As discussed in Chapters 1 and 2 various authors (e.g., MacArthur^(15,16)) have considered the joint effects of within- and between-habitat diversity being the major determinants of observed pattems of high species richness in the tropics. This approach implies that much of the adaptation within species occurs as a result of evolutionary responses to pattems of local environmental heterogeneity, and such pattems of resource distributions and biotic interactions among organisms are very diverse in some regions of the tropics. Such an approach complements considerations of broad-ranging adaptive responses such as observed pattems of geographical variation in phenotypic characters and gene frequencies within a species. It is well known that studies of geographic variation within single species and for closely related species resulted in the formulation of the concept of speciation by allopatry or geographical differentiation. But in this chapter, we are concemed with adaptation in local environments rather than over a broad geographical range.