Continental drift and climate change have played an important role in the creation of the Earth's rainforests.

Continental Drift

The distribution of plants and animals in the tropics today is strongly influenced by continental drift that has occurred over the last 140 million years.

At first, there was a great southern land mass, Gondwana and a northern one, Laurasia.

Between about 140 and 120 million years ago Africa, South America, Antarctica, India and Australia began to split apart.

India then split off and moved north. It collided with Asia about 55 million years ago collided. Today it continues to underthrust the Asian margin, forming the Himalayas and the Tibetan plateau.

The southern landmasses continued to drift apart.

About 53 million years ago, Australia split from Antarctica.

15 million years ago, the northern and southern continents collided to form the Malay Archipelago.

Climate Change

The extent of the tropical rainforests has waxed and waned with climate fluctuations.

During the Pleistocene period, glacial and interglacial episodes alternated, with profound effects on the range of tropical organisms.

During glacial episodes, sea levels are lower. The climate in the tropics is more seasonal.

During interglacial episodes, sea levels are higher and tropical climates are wetter and more uniform.

Interglacial episodes have occupied only a fraction of the last two million years. We are living in an interglacial episode right now.