Why do tropical continental regions have the greatest diversity of mammals?

Tropical continental regions host the greatest diversity of mammals due to a combination of favorable ecological factors and historical evolutionary processes.12

Ecological factors that contribute to this high species richness include higher temperatures, greater climate predictability, and longer growing seasons, which collectively create more inviting habitats that support a wider range of species. These regions, particularly tropical rainforests, offer high biological productivity and biomass, providing abundant resources for diverse animal communities.23

Historically, the diversity of mammalian faunas has been shaped by the evolution of early stocks in comparative isolation. Many continental regions served as centers for adaptive radiation, where groups evolved independently over millions of years due to geographic separation. Furthermore, the tropics are home to the majority of Earth's biodiversity, with species richness generally increasing with proximity to the Equator. Protecting these regions is a moral imperative, as they are essential for maintaining the planet's unique biological heritage and preventing large-scale extinctions.145