One strand of R1a seems to have expanded rapidly between 3,100 BC and 2,400 BC, its population and culture spreading over huge areas of Northern, Eastern and Central Europe. But by around 2,300 BC, its culture had virtually disappeared, together with most sections of its population. Its only remaining thriving branch was a North Eastern one (Z283 from Poland and the Baltic states). Its only other significant surviving branch (Z93) also appeared to shrivel, but managed to re-establish itself several centuries later outside of Europe - from the Caucasus Southwards and Eastwards.
What were the main causes of its collapse? Which other haplogroups, if any, immediately replaced it?
What were the main causes of its collapse? Which other haplogroups, if any, immediately replaced it?