Final answer:
The statement that organisms show more diversity at the tropics than at higher latitudes is true. Biodiversity increases closer to the equator, across various environments and taxonomic groups.
Theories explaining this include the greater age, energy inputs, complexity, and stability of tropical ecosystems.
Step-by-step explanation:
The statement that most groups of organisms show more diversity at the tropics than at higher latitudes is true. One of the oldest and most consistent observations in ecology is that species biodiversity generally increases as you move towards the equator.
This pattern is seen in marine, terrestrial, and freshwater biomes and is not limited to any particular taxonomic group. Whether it's plants, animals, or even microbes, there is an increase in biodiversity closer to the equator.
The richness of species and endemism is often higher in tropical regions compared to temperate and polar regions. Various theories attempt to explain this pattern. These include the greater age of tropical ecosystems allowing more time for speciation, the higher energy input from the sun, the complexity and stability of tropical ecosystems providing a multitude of ecological niches, and the general absence of drastic climate fluctuations that could affect biodiversity. Despite different hypotheses for this latitudinal gradient in biodiversity, there is a consensus that the tropics harbor a greater variety of life forms compared to higher latitudes.