BBC: Ice Age bears may have been wiped out when humans began to take over their caves, scientists claim. A new DNA study shows that cave bear populations started to decline around 50,000 years ago, coincident with the time that human numbers increased. Caves were essential for these Ice Age bears to hibernate during the winter months. The arrival of human “squatters” who occupied caves made the bears homeless, leading to their untimely extinction. The findings are …