People, why do you focusing yourself on R1a? Its such a nonsense. All Whites are Slavs (ie Sarmatians / ie Thracians) in origin. Different happlogoups and genetic variations are normal thing. Our kind lived on inter-continental level since time immemorial. Time, geography, climate, food, minerals in soil and water, etc, all left its trace on gentics of people.
They are kin not fellows. And they would be fine. You know, our ancestors in past even shared their wives. Wise people share even today. Many even don't know they share, live lives in delusion.
Genetically, the closest relives to the Polish are ukrainians, croatian and hungarians.
Probably Poles are closer to ethnic Russians and Belarussians than to Hungarians and Lithuanians. The later aren't even Slavic nations. Culture/religion and genetics is not the same thing.
From what I recall less than 10 percent of the population can actually trace a genetic line back to their original homeland... (many more would like to claim such ancestry but genetic tests say no....)
Common family names like Cseh (Czech) Szerb (Serb) Horvath (Croat) and Lengyal (Pole) should be a clue as well (IIRC over 100,000 immigrants moved to Budapest from the Czech areas in the 19th century and became magyarized in a single generation - there was also some.... forced magyarization as well).
(IIRC over 100,000 immigrants moved to Budapest from the Czech areas in the 19th century
Another wow. I had no idea. Sounds so unusual coz from Adventures of Good Soldier Schweik, one of my fav books, I learnt that Germans and Czechs considered themselves culturally superior to barbarian Magyars.