The Coxcatlan caves in the Valley of Tehuacán provide evidence for agriculture in components dated between 5000 and 3400 BC. Similarly, sites such as Sipacate in Guatemala provide maize pollen samples dating to 3500 BC. It is estimated that fully domesticated maize developed in Mesoamerica around 2700 BC. Mesoamericans during this period likely divided their time between small hunting encampments and large temporary villages. Around 1900 BC, the Mokaya domesticated one of the dozen species of cacao. A Mokaya archaeological site provides evidence of cacao beverages dating to this time. The Mokaya are also thought to have been among the first cultures in Mesoamerica to develop a hierarchical society. What would become the Olmec civilization had its roots in early farming cultures of Tabasco, which began around 5100 to 4600 BC.