Hi,
In stone age people lived in groups. Each group had hunters and gatherers. Hunters ware responsible for providing meat they have created new hunting tools like bows and arrows as well as sharp sticks to hunt down different animals. Since they already knew the fire they started cooking meat, therefore their jaw evolved from bigger to smaller because they didn't had to eat raw meat again. They also started to make clothing from animal skins because it was very cold after the last ice age.
