The settlement history of Eastern Europe is more similar to that of Northern Asia than that of Western Europe, reflecting significantly colder and drier climates than the latter. Although Eastern Europe was subject to limited occupation along the southern margin during the Middle Pleistocene, it was not widely settled until the Neanderthals colonized the southern half of the East European Plain during the earlier Late Pleistocene (Stage 5). The Neanderthals' adaptation to cold climates seems to have been heavily based on morphology and lacked sufficient flexibility to allow them to cope with the extreme conditions of the Last Glacial on the East European Plain, parts of which were abandoned during the early cold phase (Stage 4). Modern humans occupied Eastern Europe during the succeeding period (Stage 3), rapidly developing a host of technological solutions to the challenges posed by these environments.