How did early human societies develop and create new technologies and cultural forms?

Scientists who study the history of the earth use a variety of systems to classify and divide time. Geologists and paleontologists divide time into periods that last many millions of years, determined by the movements of continents and the evolution and extinction of plant and animal species. During the nineteenth century, archaeologists coined labels for eras of the human past according to the primary material out of which surviving tools had been made. Thus the earliest human era became the Stone Age, the next era the Bronze Age, and the next the Iron Age. They further divided the Stone Age into the Paleolithic (Old Stone) era, during which people used stone, bone, and other natural products to make tools and gained food largely by foraging — that is, by gathering plant products, trapping or catching small animals and birds, and hunting larger prey. This was followed by the Neolithic (New Stone) era, which saw the beginning of agricultural and animal domestication. People around the world adopted agriculture at various times, and some never did, but the transition between the Paleolithic and the Neolithic is usually set at about 9000 B.C.E., the point at which agriculture was first developed.