Tropical mountains have more biodiversity than temperate mountains, and temperature is the key according to research led by Simon Fraser University. The study proves the importance of temperature variation for biodiversity.

Using fossil insects, the researchers looked at ancient tropical mountains that are now in temperate regions. They found biodiversity was much higher in the past.

Seasonal changes in temperate areas mean animals and plants are adapted to wide temperature ranges, and can spread up, down and between mountains. In the season-less tropics organisms are adapted to narrower ranges and evolve into many new species.