In global phytogeography and evolutionary biology, why do the tropical rainforest flora and fauna of the Western Ghats exhibit strong disjunct generic affinities with the rainforest ecosystems of Southeast Asia and Madagascar?

💡 Solution & Explanation

The biological affinities of the Western Ghats stem from its history as an isolated Gondwanan fragment that drifted across the Indian Ocean, preserving ancient lineages and later receiving Eurasian immigrants after the continental collision. Marine mammals do not disperse terrestrial rainforest flora across oceans. Pleistocene glaciations did not create continuous ice sheets across the tropical Indo-Malayan realm. Ancient maritime trade introduced some economic crops, but natural disjunct distributions reflect deep geological and evolutionary history.