The Indo-European language family is a collection of related languages that probably arose in Anatolia and is now spoken all over western Eurasia. Its modern descendants include the Celtic, Germanic and Italic or Romance languages of western Europe, the Slavic languages of Russia and much of the Balkans, and the Indo-Iranian languages including Persian, as well as Sanskrit and most of the languages of the Indian sub-continent.
Language evolves faster than genes and language is predominantly vertically transmitted. Similarities and differences among vocabulary items, then, play the same role for cultural phylogenies as genes do for species trees, and provide greater resolution over short timescales. The Indo-European language tree is one of the most carefully studied of these language phylogenies
With a phylogenetic tree in hand, the authors recorded the presence or absence of each of 275 fairy tales in fifty Indo-European languages...Of the 275 tales, the authors discarded 199 after performing two tests of horizontal transmission...This left a group of 76 tales for which vertical transmission over the course of Indo-European history was the dominant signal for the patterns of shared presence and absence among contemporary societies. Hänsel and Gretel didn’t make this cut, but Beauty and the Beast did.
Evolutionary statistical methods were then applied to calculate a probability that each of the tales was present at each of various major historical splitting points on the Indo-European language phylogeny, taking account of uncertainty both in the phylogeny and in the reconstructed state. Calculating the ancestral probabilities depends only upon the distribution of tales in the contemporary languages in combination with the phylogenetic tree and so neatly gets around the problem that few if any tales exist as ‘fossil’ texts...Fourteen of the 76 tales, including Beauty and the Beast, were assigned a 50% or greater chance of having been present in the common ancestor of the entire western branch of the Indo-European languages. ..
A further four of the fourteen tales — but not Beauty and the Beast — had a 50% or greater probability of being present at the root of the Indo-European tree. A proto-Indo-European origin for these four tales represents a probable age of over 7,000 years. The tale with the highest probability (87%) of being present at the root was The Smith and the Devil whose story of a smith selling his soul to the devil is echoed today in the modern story of Faust. The authors suggest that metal working technology — as implied by the presence of a smith — could have been available this long ago.
Considering all these notions might lead us to ask why not more of the fairy tales appeared right back at the Indo-European root, or perhaps to wonder if some could go back even further. Perhaps some do. Flood myths appear in many of the world’s cultures, with some speculation that they date to the end of the last Ice Age perhaps 15,000 to 20,000 years ago when sea levels rose dramatically — if true, the western Bible story of Noah is just a comparatively recent hand-me-down.