Read this and answer the question. If the question is unanswerable, say "unanswerable".

The altitude and size of the range affects the climate in Europe; in the mountains precipitation levels vary greatly and climatic conditions consist of distinct zones. Wildlife such as ibex live in the higher peaks to elevations of 3,400 m (11,155 ft), and plants such as Edelweiss grow in rocky areas in lower elevations as well as in higher elevations. Evidence of human habitation in the Alps goes back to the Paleolithic era.

Evidence of human habitation in the Alps goes as far back to what era?
Paleolithic era