Most males in Poland carry Y-chromosomal lineages that have recently expanded over Central Europe

[Peterski]

Link to study:

https://link.springer.com/article/10.1007/s00439-025-02781-7

Abstract:

Previous studies on Y-chromosomal haplogroup diversity in Poland have been focused mainly on macro-haplogroups. Consequently, younger subclades have rarely been explored to elucidate the relatively recent history of the Polish population. Here we present the results of deep genotyping of 598 chromosome Y sequences from modern Poland and demonstrate that about 60% of Polish males can be assigned to subhaplogroups that are both relatively young and widely distributed among different Slavic populations, thus supporting the scenario in which Early Slavic mass migration and territorial expansion took place in the first millennium of the common era. While most of those young Slavic-associated subclades are part of haplogroup R1a, other haplogroups, including I2a, R1b and E1b, are also represented by specific subclades, which together may constitute an important clue when trying to identify the location of the Proto-Slavic homeland based on ancient DNA data. Additionally, we have identified two specifically Polish subclades (I-Y6343 and R-Z17913, from haplogroups I1a and R1b, respectively) that likely descend from Late Ancient or Early Medieval founders representing the local Pre-Slavic population of the Roman period.

[Peterski]

An excerpt from the study:

"As seen in Table 1, most of the 18 Slavic-associated Y-chromosomal subclades that have been identified in this study descend from single founders dated to the second half of the first millennium BCE, which indicates that the territorial expansion of the Early Slavs must have started not earlier than the turn of the era. When additionally assuming that this was a mass migration process rather than just a movement of individual founders, one needs to add at least a couple of centuries to let each of those major subclades significantly increase in size and make the expanding Late Proto-Slavic community populous enough to allow each migrating group to include many people from different subclades. In fact, many of those major Slavic subclades include younger branches that still show very wide geographic distribution. Unfortunately, younger subclades are usually much smaller and thus associated with lower frequencies, which makes the analysis of their distribution using public databases more difficult. Nevertheless, we were able to find multiple examples of very widely distributed younger branches with TMRCA ages below 2000 years. More significantly, some of them, like I-Z16983, I-FT16449 (both being part of I-Y3120), R-YP613 (under R-Y2609) or R-Y132937 (under R-YP1337) were found to be present among Eastern, Western and Southern Slavs despite descending from individual founders estimated to have lived as late as the 3rd-5th cent. CE (supplementary Table S3 and supplementary Figure S6), which suggests that mass migrations of Early Slavs could not have started much earlier than the middle of the 1st millennium CE."

Another excerpt:

"The results reported in this paper show that the majority of modern Polish Y-chromosomal lineages belong to young yet relatively large subclades that are common in other Slavic-speaking populations. This strongly supports the hypothesis of Early Slavic mass migrations dated to the middle of the first millennium CE and is consistent with previous studies demonstrating that modern populations of Central, Eastern and South-Eastern Europe share a very significant amount of recent genetic ancestry (Ralph and Coop 2013) that likely comes from an ancient population resembling modern Poles or Lithuanians (Hellenthal et al. 2014; Busby et al. 2015). It is also worth mentioning that a good correlation between the modern Y-chromosomal and autosomal data in this part of Europe has previously been noted by others (Kushniarevich et al. 2015), so the major conclusion from all these results is that Early Slavic migrations were not just a movement of relatively small male-dominated elites. Instead, the migration process likely involved much larger groupings with both male and female individuals equally contributing to the final outcome, as recently suggested based on ancient DNA data (Olalde et al. 2023)."

[Power77]

So Poles are mostly Slavs (mostly descended from bottlenecked variants of R1a)? Who knew lol.