|Cave bear||As humans migrated out of Africa, the average mammal size in the newly occupied continents started to shrink, often to sizes even smaller than those found in Africa.
A clear pattern emerged – the animals that survived tended to be smaller than those that did not.|
From a life-history standpoint, it makes sense. If you kill a rabbit, you’re going to feed your family for a day. If you can kill a large mammal, you’re going to feed your entire village for a week.