Throughout the Preclassic period the Maya adapted to diverse environments. The diverse environments provided opportunities for specialized crafters. The products that were created were than used to trade for other goods. The Maya settlements began to grow in not only size, but complexity as well. During the Middle Preclassic Maya society saw increased social and political complexity. It also marked interaction with other Mesoamerican groups. Evolution of society to a more complex society can be seen in the development of large public works, carved monuments, and evidence of warfare. These developments would have been fueled by increased food production, expansion of trade, and the rise of craft specialization. There is also evidence of an elite