The earliest history of human dance is a continuing mystery. From the evidence of illustrated ceramic fragments, some archaeologists have speculated that dance originated some 5,000 to 9,000 years ago in early agricultural cultures located in a swath running from modern Pakistan to the Danube basin. Others, however, have expressed caution regarding the reconstruction of social behavior from such sources. Speculation aside, specific knowledge of prehistoric dances is lacking, and thus many experts have extrapolated dance history from the preserved ritual dances of various preliterate societies.