Dr. Tyson concludes that certain footprints were made by a hominid. Dr. Tyson's support for this is the shape of the footprints, which have a somewhat square heel and a big toe right next to the next toe. These are human-like footprint characteristics.

Dr. Rees concludes that the footprints were not made by a hominid. Dr. Rees' support is that if a hominid made the footprints, then that hominid must have walked with a strange cross-stepping gait. This gait would have necessitated stepping with the left foot to the right of the right foot, and so on.

Drs. Tyson and Rees are examining the same footprints, but come to different conclusions about whether the footprints were made by a hominid. In coming to these conclusions, the two paleontologists examine different characteristics of the footprints: Dr. Tyson focuses on the shape of the footprints, whereas Dr. Rees focuses on how the footprints are placed relative to each other. Neither paleontologist denies the evidence of the other; they just disagree about what evidence is most important.