In each of the following passages,
a. What data are to be explained?
b. What hypotheses are proposed to explain them?
c. Evaluate the hypotheses in terms of the criteria presented in Section 13.3, pp. 564–566.

Humans, apes, and dolphins are highly social animals with large brains; they have been shown to be aware of themselves by recognizing themselves in a mirror. Most animals pay very little attention to their reflections in a mirror. Elephants are like humans in being large-brained and empathic, but they don’t share a relatively recent common ancestor with humans, like apes do. Might they also recognize an image of themselves? Yes, they do. Elephants at the Bronx Zoo, in New York City, inspected themselves with their trunks while staring at their reflections in a huge mirror. One of the elephants (but only one) completed the highest level of self-recognition, called the “mark test.” Researchers placed a white X above one eye of each elephant. After approaching the mirror, this elephant touched the mark with her trunk 12 times in 90 seconds—confirmation that she believed that what she saw in the mirror was indeed herself.
—Reported by Diana Reiss, of the Wildlife Conservation
Society and Columbia University, in Proceedings of the
National Academy of Sciences , November 7, 2006