Painting of Wallace's flying frog

'[T]he variability of the toes which have been already modified for purposes of swimming [...] enable an allied species to pass through the air like the flying lizard.'
Alfred Russel Wallace

Wallace discovered this frog, now known as Wallace's flying frog (Racophorus nigropalmatus), in the Borneo jungle in 1855.

Fascinated by the frog's ability to glide through the air, he painted this picture and wrote on the back 'descended from a high tree as if flying'.

Wallace was already interested in the idea of evolution, and for him the discovery of this frog was yet another hole in the idea that species were fixed and unchanging from the moment of their creation. It was clearly a frog - a group of animals not previously known for their flying ability - yet it had turned its webbed toes to another use.

The frog was not a perfect swimmer, nor a perfect flier, but it had the ability to do both. Its form suggested that it had adapted, rather than been created.

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