A few weeks ago I discussed the phylogenetic analysis of the tale of Little Red Riding Hood (The phylogenetics of Little Red Riding Hood). In that case, I pointed out that historical reconstructions require a rooted tree, and I discussed various possible methods for rooting the unrooted trees produced by the data analyses.
This is not the only time that phylogenetics has been applied to myths or tales. For example, d'Huy (2013a) has studied the prehistoric Polyphemus tale belonging to the European and North Amerindian areas, and d'Huy (2013b) has studied the mythological motif of the Cosmic Hunt linked to the Big Dipper constellation (typical for northern and central Eurasia and for the Americas but unknown on other continents). In the first case a binary matrix of 98 characteristics for 44 versions of the tale was used, and in the latter 93 characteristics for 47 versions. Both of these studies have rooted trees.
In the latter case, a novel method of rooting the tree was used. The unrooted tree was successively rooted with each of the likely versions of the tale as outgroup. In each case the ancestral tale (the protomyth) was reconstructed and the ancestral states of the tale's characteristics (called mythemes) were determined. The author then "selected the version that holds the majority of the wide shared mythemes (>50%) as the better root."
Unfortunately, this produced an unexpected root, as shown in the tree below. The colors in the tree refer to various geographical groupings of the tale versions.
So, I re-analyzed the data using the rooting methods that I previously applied to the Red Riding Hood analysis:
- For the bayesian analysis, I used MrBayes (2 runs, 4 chains, 1,000,000 generations, sampling frequency 1000, 25% burnin) with a relaxed clock (with independent gamma rates model for the variation of the clock rate across lineages).
- For the neighbor-joining tree I used the BioNJ algorithm in PAUP*, and found the midpoint root.
- For the parsimony analysis, I used a 200-replicate parsimony-ratchet search via PAUP*, calculated the branch lengths of the majority-rule consensus tree with ACCTRAN optimization, and found the midpoint root.
Geographically, the root chosen by the author's method is within the red group (tales from Asia), based on the idea that "arguments in favour of localization of protypical Cosmic Hunt in Asia seem persuasive (Berezkin 2005)." Unfortunately, this a priori argument seems to have excluded any testing of the possibility that more than one version is the sister to the remaining tales — that is, only single outgroups were considered.
On the other hand, all three of the alternative roots group the tales into two major clades. For the bayesian-clock root the two clades have distinct animal motifs, a herbivore and a carnivore, respectively. These clades do not correspond to any of the three variants recognized by Berezkin (2005).
The bayesian-clock root puts the red-colored (Asia) versions of the tale into one of the two major clades, as it also does with the orange group (Africa), which makes this root more consistent with the geographical groupings — that is, all of the geographical groups are in only one of the two major clades, except for the purple group (American coast-plateau / British Columbia). Both the Parsimony and NJ roots do the same thing, but as well as the purple group they also split the pink group (northeastern America) between the two major clades, which reduces their geographical consistency compared to the bayesian-clock root.
The bayesian-clock root does not support the suggestion that the Cosmic Hunt myth originated in Asia. Indeed, the bayesian tree does not support any particular geographical location. Furthermore, the polyphyly of the purple group presents an intriguing aspect of the tale's history.
Yuri Berezkin (2005) The cosmic hunt: variants of a Siberian—North-American myth. Folklore 31: 79-100.
Julien d'Huy (2013a) Polyphemus (Aa. Th. 1137): a phylogenetic reconstruction of a prehistoric tale. Nouvelle Mythologie Comparée 1: 1-21.
Julien d'Huy (2013b) A cosmic hunt in the Berber sky: a phylogenetic reconstruction of a Palaeolithic mythology. Les Cahiers de l’AARS 16: 93-106.