ABSTRACT

Tropical biotas have evolved in an environment that possesses several unique properties (Chapters 3 and 4) and that has had a long and complex geological history (Chapter 2). As was mentioned in Chapter 1, a diversity of life forms and a complexity of biological interactions are two of the unique features of tropical ecosystems. In this chapter, we will discuss the functioning of biological populations in the relatively aseasonal environment of the tropics and examine how natural selection and organic evolution appear to operate in such places. We will then review the major patterns of biological diversity that exist globally and within the tropics, and some of the hypotheses that have been proposed to account for the high levels of species diversity that are characteristic of many tropical communities. Finally, we will discuss the conservation and management problems that are presented by tropical biotas, including those involved in human diseases.