Biodiversity varies based on latitude and altitude, with the most biodiversity found in the tropical regions near the equator and decreasing as one moves further north or south in latitude or to higher altitudes up mountains. Specifically, biodiversity is lowest in the Arctic, moderate in temperate regions, and highest in the tropics between 23.5 degrees north and south latitude, while biodiversity also decreases with increasing altitude as temperature decreases the higher one goes. The document discusses these latitudinal and altitudinal gradients in biodiversity as major global patterns.