Analysis of pollen in sediment cores from a large lake in Greece shows that nomadic livestock herders took over the region after the collapse of the Western Roman EmpireAnalysis of pollen in sediment cores from a large lake in Greece shows that nomadic livestock herders took over the region after the collapse of the Western Roman Empire Analysis of pollen in sediment cores from a large lake in Greece shows that nomadic livestock herders took over the region after the collapse of the Western Roman Empire New Scientist – Home