Give three hypotheses for explaining, why tropics show the greatest levels of species richness.
The following three hypotheses explain how tropics show the greatest level of species richness: 1. Undisturbance in the tropics: Speciation is usually a function of time, unlike temperate areas subjected to frequent glaciations in the past. This type of disturbance has not occurred or remained relatively undisturbed in tropical latitudes for millions of years. Tropical regions, thus, got a long evolutionary time for species diversification. 2. Constancy in season: In tropical regions, the environment is more constant, less seasonal, and predictable. This is not so in temperate regions. Due to this stability and constancy, niche speciation takes place at a faster rate and leads to species richness. Availability of more solar energy: Due to more availability of solar energy in the tropics, productivity is higher. This contributes indirectly to greater species diversity.
