Give three hypotheses for explaining why tropics show greatest levels of species richness.
1. Tropical latitudes have remained undisturbed for millions of years and thus, had a long evolutionary time for species diversification.
2. Tropical environments are constant, predictable and less seasonal, thus promote niche specialisation and leads to greater species diversity.
3. There is more solar energy available in the tropics, which leads to more productivity and hence species diversity.
How do ecologists estimate the total number of species present in the world?
The species diversity of plants (22 per cent) is much less than that of animals (72 per cent). What could be the explanations to how animals achieved greater diversification?
