Final answer:
Tropical regions near the equator have the greatest biodiversity due to their higher rate of endemism and numerous biodiversity hotspots. These areas have more species due to a long evolutionary history, stable climate conditions, and higher energy input from the sun, but they also face significant threats from biodiversity loss.
Step-by-step explanation:
Regions closest to the equator, known as tropical regions, would most likely exhibit the greatest amount of biodiversity. These regions are characterized by a higher rate of endemism, which refers to species that are unique to a defined geographic location and are found nowhere else in the world. Additionally, tropical regions are home to more biodiversity hotspots, areas that are both high in biodiversity and under threat from human activities.
One hypothesis for the greater biodiversity in tropical regions is the long evolutionary history of these ecosystems, which were less affected by the last ice age compared to temperate regions. This legacy has allowed for more time for speciation, the process through which new species evolve. Increased solar energy and more stable climate conditions may also contribute to the vast number of species found in the tropics.
It's important to note, however, that while biodiversity is greatest in these areas, our knowledge of the species that inhabit them is comparatively low. This, combined with recent, intense human activity, has led to a high potential for biodiversity loss, making conservation efforts in these regions critical.