Doctor Vitagliano was a paleo-climatologist.
In 1997 Vitagliano was asked by Dana Scully to study some ice core samples, though she did not say where they were found. He classified the cells inside as chimera. (TXF: "Gethsemane")
Vitagliano then called Scully to show her his findings. He tried to induce multiplication in order to get more information, but the division still could not be classified. He did not know what it was growing into. Scully then asked him to compare the samples against Scully's own DNA. It was a match, to Vitagliano's surprise. (TXF: "Redux")