Prehistoric religion is the religious practice of prehistoric cultures. Prehistory, the period before written records, makes up the bulk of human experience; over 99% of human history occurred during the Paleolithic alone. Prehistoric cultures spanned the globe and existed for over two and a half million years; their religious practices were many and varied, and the study of them difficult due to the lack of written records describing the details of their faiths.The cognitive capacity for religion likely first emerged in Homo sapiens sapiens, or anatomically modern humans, although some scholars posit the existence of Neanderthal religion and sparse evidence exists for ritual practice as early as Homo naledi. Excluding sparse and controversial evidence in the Middle Paleolithic (300,000–50,000 years ago), religion emerged with certainty in the Upper Paleolithic around 50,000 years ago. Upper Paleolithic religion was possibly shamanic, oriented around the phenomenon of special spiritual leaders entering trance states to receive esoteric spiritual knowledge. These practices are extrapolated based on the rich and complex body of art left behind by Paleolithic artists, particularly the elaborate cave art and enigmatic Venus figurines they produced.The Neolithic Revolution, which established agriculture as the dominant lifestyle, occurred around 12,000 BC and ushered in the Neolithic. Neolithic society grew hierarchical and inegalitarian compared to its Paleolithic forebears, and their religious practices likely changed to suit. Neolithic religion may have become more structural and centralised than in the Paleolithic, and possibly engaged in ancestor worship both of ones individual ancestors and of the ancestors of entire groups, tribes, and settlements. One famous feature of Neolithic religion were the stone circles of the British Isles, of which the best known today is Stonehenge. A particularly well-known area of late Neolithic through Chalcolithic religion is Proto-Indo-European mythology, the religion of the people who first spoke the Proto-Indo-European language, which has been partially reconstructed through shared religious elements between early Indo-European language speakers.Bronze Age and Iron Age religions are understood in part through archaeological records, but also, more so than Paleolithic and Neolithic, through written records; some societies had writing in these ages, and were able to describe those which did not. These eras of prehistoric religion see particular cultural focus today by modern reconstructionists, with many pagan faiths today based on the pre-Christian practices of protohistoric Bronze and Iron Age societies.