Unlike some other religions, in the Cherokee belief system, humans do not rule or have dominion over the earth, plants or animals. Instead, humans live in coexistence with all of creation. Humans mediate between all worlds in an attempt to maintain balance between them. Plants, animals, and other features of the natural world such as rivers, mountains, caves and other formations on the earth all have spiritual powers and attributes. Theda Perdue and Michael Green write in their book "The Columbia Guide to American Indians of the Southeast","These features served as mnemonic devices to remind them of the beginning of the world, the spiritual forces that inhabited it, and their responsibilities to it." Perdue also outlines the ways that Cherokee culture persisted through multiple attempts by Christian missionaries to convert them. Their strong ties to Selu, the corn mother in their creation story, put women in a position of power in their communities as harvesters of corn, a role they did not give up easily.