Where did all the young men go during 0-18 stage 2?

Recent evidence indicates that climatic conditions in Griqualand West, deteriorated with colder and drier than now during Isotope Stage 2 and that there was a concomitant (?) winter rainfall increase then to the west in Bushmanland. The archaeological record shows that Griqualand West was largely or entirely abandoned during the Last Glacial and it is presumed that population shifts took place to the lakes which then filled present-day pans in Bushmanland. One implication of this model would be that those two regions have complementary cultural stratigraphies which promise when combined to provide the northern Cape with a complete record of human history for the Upper Pleistocene and beyond.