cave art and LSD experiments alike. Ecological approaches and systems theory Gerardo Reichel-Dolmatoff relates these concepts to developments in the ways that modern science (systems theory, ecology, new approaches in anthropology and archeology) treats causality in a less linear fashion. He also suggests a cooperation of modern science and Indigenous lore. Historical origins Shamanic practices may originate as early as the Paleolithic, predating all organized religions, and certainly as early as the Neolithic period. The earliest known undisputed burial of a shaman (and by extension the earliest undisputed evidence of shamans and shamanic practices) dates back to the early Upper Paleolithic era (c. 30,000 BP) in what is now the Czech Republic. Sanskrit scholar and comparative mythologist Michael Witzel proposes that all of the world's mythologies, and also the concepts and practices of shamans, can be traced to the migrations of two prehistoric populations: the "Gondwana" type (of circa 65,000 years ago) and the "Laurasian" type (of circa 40,000 years ago). In November 2008, researchers from the Hebrew University of Jerusalem announced the discovery of a 12,000-year-old site in Israel that is perceived as one of the earliest-known shaman burials. The elderly woman had been arranged on her side, with her legs apart and folded inward at the knee. Ten large stones were placed on the head, pelvis, and arms. Among her unusual grave goods were 50 complete tortoise shells, a human foot, and certain body parts from animals such as a cow tail and eagle wings. Other animal remains came from a boar, leopard, and two martens. "It seems that the woman … was perceived as being in a close relationship with these animal spirits", researchers noted. The grave was one of at least 28 graves at the site, located in a cave in lower Galilee and belonging to the Natufian culture, but is said to be unlike any other among the Epipaleolithic Natufians or in the Paleolithic period. Semiotic and hermeneutic approaches A debated etymology of the word "shaman" is "one who knows",Hoppál 2005: 14 implying, among other things, that the shaman is an expert in keeping together the multiple codes of the society, and that to be effective, shamans must maintain a comprehensive view in their mind which gives them certainty of knowledge. According to this view, the shaman uses (and the audience understands) multiple codes, expressing meanings in many ways: verbally, musically, artistically, and in dance.