Genetic Corroboration That Lithuanian Is Fairly Basal With IE Languages

This paper (hat tip Eurogenes), in contrast, has an excellent and informative abstract that provides insight into the the genetic origins of Lithuanians in a historical context and also regarding the proper place of the Lithuanian language in the Indo-European family tree.

When combining the new data we generated with external datasets, we confirmed that Lithuanians locate within the expected European context, even though they also present particular genetic distinctiveness when compared to neighbouring populations. In addition, the inclusion of ancient individuals from different periods across western Eurasia in the analysis allowed us to distinguish the genetic signature of three main prehistorical sources shaping the distinctiveness of present-day Lithuanians: pre-Neolithic HG groups, the Early to Middle Bronze Age Steppe pastoralists and Late Neolithic Bronze Age (LNBA) Europeans. Moreover, up to three HG populations can be inferred to contribute to the main genetic component identified the Lithuanians being the contribution of the WHG and the Scandinavian HG greater than that of the EHG. On the contrary, earlier European Neolithic movements from Levant/Anatolia known to contribute to genetically differentiated populations in Europe such as Sardinians or Basques are not especially predominant in Lithuania. 

Partial genetic isolation of the Lithuanians is a possible explanation for the structure results observed. Until the late Middle Ages, the eastern Baltic region was one of the most isolated corners of Europe [27]. Moreover, after the fall of the Roman Empire in the 5th century, the eastern Baltic region was spared by the subsequent population movements of the Migration Period [26,28], which allowed the most archaic of all the living speaking Indo-European languages [1] to survive. Thus, Lithuanians could retain their cultural identity.

Urnikyte et al., Patterns of genetic structure and adaptive positive selection in the Lithuanian population from high-density SNP data, Scientific Reports volume 9, Article number: 9163 (2019), DOI: https://doi.org/10.1038/s41598-019-45746-3