This recent post on the Bad Archaeology blog provides a much-needed antidote against the Piri Reis paleobabble contagion. As author Keith Fitzpatrick-Matthews notes at the outset:

Maps of the fifteenth to eighteenth centuries are a favourite source of information for fringe writers, who use them to make a wide variety of claims. To Erich von Däniken, for instance, they are evidence for a survey of the Earth from space, carried out by extraterrestrials, while for Graham Hancock, they are evidence for an ancient sea-faring civilisation, lost beneath the sea after the melting of glacial ice at the end of the Pleistocene.

Anyone who’s put any time into the Piri Reis issue knows the above is on target. What you may not have known is that the Piri Reis discussion is based in part on selective use of evidence. I highly recommend the essay, as it covers the alleged anomalies (e.g., knowledge of Antarctica before it became ice-covered) and the Charles Hapgood trajectories that are so frequently used to defend the paleobabbling perspective of Piri Reis.