121 Extinction of Gods: Impact of Climatic Change on Religious Concepts Jiří Janák Czech Institute of Egyptology Charles University – Prague Abstract The akh and the ba count among the most important Egyptian religious concepts of human and divine beings. Both occur frequently in Egyptian texts, from its beginnings until the very dusk of the hieroglyphic script, and, coincidently, both were represented by signs in shape of birds. This study focuses on the interdependency between the term or notion and the sign and its natural model. The outcomes reveal that natural changes can have important impact upon script, ideas and religious beliefs. Although this paper represents the outcome of research on the system and cardinal concepts of ancient Egyptian religion that has been under a more general research project,¹ it deals mainly with the history of Egyptian script, as well as zoological and especially ornithological issues and problems. Thus, the original aim of the research: to grasp the original meaning of two of the key notions of Egyptian religious thought, the akh and the ba, has been supple- mented with new and unexpected findings and results. The two terms of focus, that is the akh and the ba, count among the most important Egyptian religious concepts of human and divine beings, their status, roles, and mutual relation- ships and thus they occur frequently in Egyptian texts, literally from the beginnings of the ¹ The Charles University Scientific development programme No. 14: Archaeology of non-European areas, Sub-project: Ancient Egyptian civilisation research: cultural and political adaptations of the North African civilisations in Antiquity (, BCE – , CE).