By Cooking foods

 Cooking was important for old people by making them healthier, and foods were getting better taste. 

The old people was not cooking from the first. At the first, they just ate raw meat, raw vegetable, and all of raw things. By this reason, old people, Australopithecus or Homo Erectuce, had sharper teeth at that time. By the way, their brain was getting bigger and smarter so they invented better weapons, some bowls, and fire. By using these invertions, Hunting was easier, Stating agriculture, and Using fire and cooking. In addition, since they started cooking food, their teeth have been evoluting by foods what they usually ate. Furthermore, Before they cooking, they usually got disease from raw foods; however, they had healtier food by cooking food and it was not decomposed easily. Lastly, Cooking brought a new life and made more intelligent brain. If they could not find it, we might live in cave still.