3. Give three hypotheses for explaining why tropics show the greatest levels of species richness.

 There are three different hypotheses proposed by scientists for explaining species richness in the tropics.
 Tropical latitudes receive more solar energy than temperate regions, which leads to high productivity and high species diversity.
 Tropical regions have less seasonal variations and have a more or less constant environment. This promotes niche specialization and thus, high species richness.
 Temperate regions were subjected to glaciations during the ice age, while tropical regions remained undisturbed which led to an increase in the species diversity in this region