What made the first people to develop new lands?

Scientists believe that there were several reasons why people began to settle and develop different parts of the planet. The first is the search for food. After all, primitive people were not farmers or pastoralists, but were engaged in hunting and gathering, so they constantly moved around when the food in the same place came to an end. The second is simple curiosity. It is with this that scientists explain the fact that a person from warmer and more comfortable places for life began to move north, crossed the seas and settled on remote islands.