Authors presented a lexicostatistical analysis using Swadesh list of 110
words in recent study. They are also addressed some issues with selections and
interpretations of the words in past papers , many loan-words were
included and inaccurate translations provided. http://journals.plos.org/plosone/article/file?id=info%3Adoi/10.1371/journal.pone.0135820.s008&type=supplementary
3.2. The case of the Slovenian language
Modern Slovenian belongs to the South Slavic clade according to the traditional classification of Slavic languages (Sussex, Cubberley, 2006). However, significant linguistic similarities between Slovenian and West Slavic lects have been observed earlier in number of studies. See, for example, on specific ties between Slovenian and West Slavic (e.g., Slovak) or even on support of the mixed South/West origin of Slovenian, e.g., Bezlaj, 2003, Sobolev, 2000, Bernstein, 1961, Stieber, 1972, Lekov, 1958. 19 Likewise, the Slovenian (Ljubljana koine and literary Slovenian) wordlist, available in our study (see sources below), possesses a substantial number of both South Slavic and West Slavic lexical matches (cf. similar observations in Novotná and Blažek, 2007: 195). Such a mix introduces enough incompatible characters into the input matrix to make the calculation of robust trees impossible. Due to this reason we have deliberately excluded Modern Slovenian from the current analysis. We suggest that one of the possible scenarios is that Slovenian is historically a West Slavic language being influenced by neighboring Serbo-Croatian during the last millennium. To demonstrate specific ties between Slovenian and South Slavic, on the one hand, and West Slavic, on the other, we calculated a set of NeighborNet phylogenetic networks (Bryant, Moulton, 2004; Makarenkov et al. 2006: 89–90) of Balto-Slavic languages with the use of SplitsTree4 software from the binary matrix described above; the non-parametric bootstrap test was performed with 10 000 pseudoreplicates in each case. Two additional taxa were introduced into the original dataset: Slovenian and Modern Demotic Greek, the latter as an outgroup
for the Germanic-Balto-Slavic clade.
Three networks without Slovenian (Fig. H–J in S2 File) reveal the same major clades of Balto-Slavic languages as phylogenetic trees do (Fig. B–G in S2 File) irrespective the outgroup used. Incorporation of Slovenian into network analysis reveals following: Slovenian appears to be an independent branch of Slavic languages which is nearly equally close to West and South Slavic, but distant from East Slavic (Fig. K–M in S2 File), thus supporting the putative mixed nature of Modern Slovenian. Further lexicostatistical investigation of Slovenian dialects, such as in progress in the GLD project, are needed to elucidate the place of Slovenian among Slavic languages.
Polish is more similar to Eastern Slavic languages than other west Slavic languages. Lusatian Sorbian more similar to Czech. Russian is more similar to south Slavic languages than other east Slavic languages.