The most famous item of evidence in the controversial case of the yeti can be yours. The original prints of four footprint photographs taken in a high snowfield over 50 years ago by Eric Shipton will be sold by Christie's later this month.
COMMENT: While the evidence for the yeti is unsatisfying at best, no one has ever explained these footprints. Options:
1. An unknown animal.
2. Prints of known animals (or humans) expanded by melting and refreezing. This is easy enough to disprove experimentally. Tracks melt into a blob - they don't expand in a way that gives you clear edges and well-defined toes.
3. A hoax. No evidence Shipton and his companion Ward hoaxed the prints has ever been offered.
4. Simply, a mystery.