Michael Cremo compares primary and secondary sources in archeology and finds that contrary evidence is minimized or absent in secondary sources like text books and journal articles, but common in the primary source data.
For example, he finds two seperate radiographic techniques both dating separate strata of a Mexican dig site showed it to be at least 250,000 years old. Archeologists discarded both data sets because "it couldn't possibly be right." Cremo found this pattern repeated many times. The accumulated dissonant data may be substantive enough to warrant a review of the evidence concerning the history of humans on the earth.
