Mummies are typically divided into one of two distinct categories: anthropogenic or spontaneous. Anthropogenic mummies were deliberately created by the living for any number of reasons, the most common being for religious purposes. Spontaneous mummies, such as Ötzi, were created unintentionally due to natural conditions such as extremely dry heat or cold, or anaerobic conditions such as those found in bogs.[15] While most individual mummies exclusively belong to one category or the other, there are examples of both types being connected to a single culture, such as those from the Ancient Egyptian culture.