Today's tour of the aeons before the appearance of the human species on Earth begins with a rare and most important piece of evolutionary evidence provided by the fossils of a creature called Tiktaalik which were discovered on Ellesmere Island, Canada, in 2004.

They say that if you want to boil a frog, you don't throw it into scalding water as the creature will simply leap out. Instead, you turn up the heat slowly.

Scientists tackling the thorny problem of a foreign superweed hope a humble insect could halt its rampage across the UK's gardens.

More than half of all amphibian species in Europe could become extinct by 2050 because of a combination of habitat loss, infectious diseases and the effects of climate change, scientists have found.

What do a blind salamander that can go without food for a decade, a frog so small that it fits on a drawing pin and another that lives only in the human burial grounds have in common?

They were the first animals with backbones to walk on land. They witnessed the rise and fall of the dinosaurs and were present at the birth of a bipedal ape who went on to become the most destructive species the planet has ever known.