UK: Rainforest collapse prompted reptile evolution

Global warming devastated tropical rainforests 300 million years ago and triggered an evolutionary burst amongst reptiles that led to the rise of dinosaurs, 100 million years later, according to scientists at Royal Holloway, University of London and the University of Bristol.

Writing in the journal Geology, they say the event happened during the Carboniferous Period when Europe and North America were located on the Equator, covered by steamy tropical rainforests. But as the earth's climate became hotter and drier, rainforests collapsed and this triggered reptile evolution.

Dr Howard Falcon-Lang, from the department of earth sciences at Royal Holloway, said climate change caused rainforests to fragment into small 'islands' of forest. This isolated populations of reptiles and each community evolved in different directions, leading to an increase in diversity.

Bristol's Professor Mike Benton said this was a classic ecological response to habitat fragmentation: "You see the same process happening today whenever a group of animals becomes isolated from its parent population. It's been studied on traffic islands between major road systems or, as Charles Darwin famously observed in the Galapagos, on oceanic islands."

The scientists studied the fossil record of reptiles before and after rainforest collapse. They found that reptiles became more diverse and even changed their diet as they struggled to adapt to rapidly changing climate and environment.