"trustees for humanity"

We are all descendants of the great makers and discoverers. We are human. However...

What makes a cultural artifact property of a particular group? Past cultures, or their ruins, end up inside the borders of modern states, and then become part of that state's "heritage". Odd. The modern Egyptian state wants to copyright the images of the ancient ruins within its borders. Odd. The Mayan civilization rose and fell before the idea of a Mexican mestizo culture or a Mexican state was even a possibility, yet the Mayan is now the Mexican. Odd. In the United States it seems nearly every modern American claims 1/8 Cherokee blood, or some such, and we revere the ideal of some imagined Native American past, though we ran roughshod over nearly aspect of Native American life and continue to disrespect individual Native Americans and whole tribes. Odd. 

There is no mechanism for a "trusteeship for humanity". There are international treaties, and UNESCO, but really, there's no reliable international structure. It's something we can look forward to and look into in an increasingly cosmopolitan world. Again, I direct you to Appiah's chapter, Whose Culture Is It, Anyway" for a fuller discussion of the issues.