It is the ultimate, infallible tribute to a Briton: placing their portrait on a banknote alongside images of their life and work. But now a leading UK biologist has announced that pictures on the ￡10 note, which commemorates the achievements of Charles Darwin, are 'little better than fiction'.

Professor Steve Jones, of University College London, said putting a hummingbird on the current ￡10 note was a blunder. 'The note is supposed to encapsulate Darwin's trip to the Galapagos, with him looking at a hummingbird as a source of inspiration. But there are no hummingbirds on the islands,' said Jones at last week's opening of the Natural History Museum's exhibition, Darwin.

'Mockingbirds and finches were important in getting Darwin thinking about evolution, but hummingbirds played no role at all. Presumably the artist just happened to like them.' Jones said he had written to the Bank of England but had received no answer. A spokesman for the Bank referred The Observer to its website which insists the hummingbird was of 'the type characteristically found in the region of the Galapagos Islands'.

But hummingbirds are not even mentioned in On the Origin of Species, said Jones. 'So why depict them? This is not a trivial issue. We are surprised by the numbers of people who believe in creationism and rubbish like that only to find the currency in which we place our trust is telling us lies about evolution.'

Robin McKie, science editor