Who Art You?

Two recent articles reminisce a long standing question about art. One about how our beloved cave drawing grand-fathers turn out to be younger than we thought (here). Another one about the art of copycating as mastered by Pettibone during the Pop Art era (here).

Lichtenstein Masterpiece 1962, Roy Pettibone 1975

Although these articles deal with painters separated by a long line of births and deaths, they produce similar after thoughts.
1) Should Pettibone's pieces be considered works of art when compared to the originals which inspired them?
2) Suppose all these originals disappear or are destroyed, does the status of Pettibone's paintings change?
3) And what about if in 100 years we all think that Pettibone's paintings are the originals, will we praise them as masterpieces?
4) Just as we praise some cave drawings we recently found but that may well be mere reproductions of other original drawings forever lost.

Hum...