In addition, we still lack an evolutionary tree for languages as linguists have not yet reached a clear consensus on their classification [21], and even questioned the validity of branching trees as an adequate representation of linguistic patterns of divergence [22].
To cite just one example, Sandoval et al. (2009) suggested that genetic divergence predated linguistic diversification in Mexico.
Repeating the analysis using this measure, we found that the KL divergence across all the linguistic families considered remains almost constant around 3.6 bits/word, as shown in Figure 2B.
The linguistic question that minimizes the sum of average KL divergences, D KL (S y )+D KL (S n ), of the children nodes is used to split each node in the decision tree.
As for the comparison between linguistic groups (schemes 5 6), the AMOVA results seem to suggest that the level of divergence between tribes is not enhanced by differences in social habits (i.e., Φ ct is not statistically different from 0).
The large divergences observed in other cultural aspects of the Maya, such as linguistic ones, have probably developed very recently in the overall history of the Maya.
This gradual divergence from the language of Plato and Demosthenes was viewed as a species of linguistic decadence by an influential school known as the Atticists, who unceasingly castigated the use of Koine forms by writers.
Finally, we did not find significant population structure in the maternal lineages when considering the four main and distinct linguistic groups represented in our Mexican samples (Oto-Manguean, Uto-Aztecan, Tarascan, and Mayan), suggesting that genetic divergence predates linguistic diversification in Mexico.
However, their languages show sufficient divergence from the main Muskogean languages and from each other to warrant semi-independent status as linguistic isolates.
We also considered another mechanism to neglect linguistic structure in the texts that makes it possible to relate the relative entropy to the Kullback-Leibler divergence between real and random texts, and thus set the analysis within the framework of standard information theory.
