Someone recently suggested a rule that if the headline is in the form of a question, the answer is "No." "Is this proof the Virgin Queen was an imposter in drag? Shocking new theory about Elizabeth I unearthed in historic manuscripts" Umm. The "proof" is a chapter in a book by Bram Stoker, which I suppose counts as "historic" but hardly counts as "new."
The BBC, despite throwing scare quotes around as though ink was free, is often fairly uncritical of news stories that claim the mantle of science. Fairy tales are old. Umm yes? They're often variations (East of the Sun and West of the Moon, anyone?) on mythic themes you find everywhere. Good stories can travel back and forth--unless you have ancient records you don't know the ancestry of a modern fairy tale. There's no guarantee a group was isolated. This isn't like genetics--large groups of people only rarely move around. Stories are lightweight and storytellers often look to expand their repertoire.
Are Aesop's fables related to Anansi stories? Or to tales from India? Or, given travel back and forth (not always voluntary), are they all related to each other? If you collect tales from an apparently isolated tribe in South America, imagine the chances that one or more of them have echoes of Spanish stories--they've had 500 years to diffuse.
UPDATE: See AVI for more details