What's the explanation behind the 'Map Skeleton' in Pirates 4?

Question

In Pirates of the Caribbean 4: On Stranger Tides, there's a scene where Captain Barbossa and Jack Sparrow are in a ship looking for two silver chalices.

Upon finding that the Spanish have taken the chalices, they consult a map that a skeleton on a bed is holding. However, as Jack attempts to takes the map, the skeleton his moves his head to look at Jack. At first, this seemed like the result of disturbing the skeleton, but when Jack let's go of the map, after the request of Barbossa, the skeleton stops looking at Jack as if it is somehow alive.

So my question is: What's going on? Are the actions of the Map Skeleton ever explain anywhere? Is it 'alive' or is it just moving as a result of being disturbed?

Answer 1

The corpse is Juan Ponce de León, a Spanish explorer and conquistador. He led the first European expedition to "La Florida", which he named. Though in popular culture, he was supposedly searching for the Fountain of Youth, this is likely a myth, as there is no contemporary evidence to support the story.

However, in Pirates of the Caribbean, he and his ship the Santiago were stranded on the edge of a cliff of an unknown island, during his last expedition. Inside the ship were the Chalices needed to complete the profane ritual performed to access the power of the Fountain of Youth. He also had with him his map, which allegedly showed the path to the Fountain, itself. It is unknown what would happen if someone were to take the map, as Jack tried to do, but until someone tries, Ponce de León will sit in his cabin examining the map for all eternity.

Answer 2

the skeleton does look at Jack and then it does look away

I always assumed there was some kind of magic that either kept the being alive or animated it with orders to guard the map but I do not believe there is an actual explanation anywhere