Roman copies of Greek sculpture

As Rome expanded into the Greek world, vast numbers of Greek statues were brought to Rome as booty, through extortion or by trade, and by the 2nd century BCE most sculptors working in Rome were Greek. The Romans collected the masterpieces of Classical Greek sculpture and copied them on a large scale for public places and private houses, spreading Greek forms across the empire. Major Classical sculpture was mostly cast in bronze, which was expensive and generally recycled, so many works survive only in marble copies made for the Roman market. Polykleitos's Doryphoros (Spear-Bearer), cast around 440 BCE, is one: its bronze original is lost and it is known only from marble copies, mainly of the Roman period. Portraiture is often seen as the main strength of Rome's own sculpture.

Compare the faces of the gods with the faces in the Roman portraits: which shows an ideal beauty, and which looks like someone who actually lived?

What was the original of this marble statue made of?