Saccharides are a food source rich in energy. Following the agricultural revolution 12,000 years ago, human diet began to shift more to plant and animal domestication in place of gathering and hunting. Large polymers such as starch are partially hydrolyzed in the mouth by the enzyme amylase before being cleaved further into sugars. Therefore, humans that contained amylase in the saliva would benefit from increased ability to digest starch more efficiently and in higher quantities. Despite the obvious benefits, early humans did not possess salivary amylase, a trend that is also seen in evolutionary relatives of the human, such as chimpanzees and bonobos, who possess either one or no copies of the gene responsible for producing salivary amylase. This gene, AMY1, originated in the pancreas. A duplication event of the AMY1 gene allowed it to evolve salivary specificity, leading to the production of amylase in the saliva. In addition the same event occurred independently in rodents, emphasizing the importance of salivary amylase in organisms that consume relatively large amounts of starch.