The Paleolithic Era (or Old Stone Age) is a period of prehistory from about 2.6 million years ago to around 10000 years ago. The Neolithic Era (or New Stone Age) began around 10,000 BC and ended between 4500 and 2000 BC in various parts of the world. In the Paleolithic era, there were more than one human species but only one survived until the Neolithic era. Paleolithic humans lived a nomadic lifestyle in small groups. They used primitive stone tools and their survival depended heavily on their environment and climate. Neolithic humans discovered agriculture and animal husbandry, which allowed them to settle down in one area. The Mesolithic era followed the Paleolithic era but the period of the Paleolithic—Mesolithic boundary varies by geography by as much as several thousand years.
Professional organizations that controlled how their industry operated and protected their members' interests against outsiders were called "special interest groups", since they look out for the interest of their members.
