The First Agricultural Revolution was the transition of humans from nomadic hunting/gathering to sedentary agricultural production of domesticated plants and animals. A result of the warming period directly after an Ice Age, the first place to of recorded this Revolution was the Fertile Crescent in the Middle East.
The group that started the First Agricultural Revolution were the early members of humanity that settled in the Fertile Crescent area of the Middle East. Other groups achieved similar results later in China (unknown if independent from Fertile Crescent) and South America. The members of this group were the first to settle into a specific area of land and stay sedentary for long periods of time.
During the First Agricultural Revolution, Humans radically changed their behavior. During this period, humans began settling in to single areas and began cultivating the land, planting crops, and raising animals. The crops became domesticated as humans continued their use and animals became tame enough to be used for easy meat and pets/companions. The earliest examples of this behavior appeared in fertile areas around rivers primarily. Examples of early settlements include Eridu, Ur, and Nineveh.
Where did it Occur?
The first recorded evidence of the First Agricultural Revolution occurring is in the Fertile Crescent, a region in the Middle East that includes most of Iraq (Known as Mesopotamia in the past), Syria, Lebanon, Israel, and the Nile River basin in Egypt. Other occurrences of the First Agricultural Revolution appeared Later in places like China and South America. Specific locations of the Revolution have been lost to war, looters, and time. The areas around them have been heavily changed since.
The Fertile Crescent
The First Agricultural Revolution started around 11,000 BC. The exact timing is uncertain and will likely remain that way as little written record has survived. China is known to have experienced the Revolution later than in the Fertile Crescent/Mesopotamia, though timing is, again, uncertain. In the Americas, the First Agricultural Revolution likely started much later than either China or the Crescent. Some scholars believe that it occurred in the Americas from 2000 BC up to the discovery of the Americas by the Europeans as some Native Tribes had not progressed to the First Agricultural Revolution by that time.
Most scholars agree that climatic changes from the end of the last Ice Age have the greatest impact on the reason for the dramatic shift of the First Agricultural Revolution. Areas where the Revolution first cropped up were well irrigated and warm, making for ideal farming conditions. The areas center around larger rivers or groups of them. The exact reason why is unknown.
Long Term Effects
The long term effects of the First Agricultural Revolution are some of the most broad reaching of any event in human history. Without sedentary living and agriculture, most societal changes and technological innovations would not of been possible. The growth of the human race from a couple hundred thousand to the seven billion would not of been possible without the sustained food production that results from agriculture. The technological innovations and revolutions that occurred after this Revolution would not of been possible without the sedentary lifestyle.