Over the centuries, various luthiers have probably tried every wood they could get their hands on. Some didn’t sound good, some were too heavy, some were more crack prone, etc. Availability was a factor too. They tended to use woods that they could get easily. From that evolutionary process, violin family instruments ended up with certain woods:

• The back and sides are maple because that’s a strong, durable wood, resonates well, and is relatively easy to bend into the curves of the ribs.
• The top is spruce, because it is strong, easy to carve into the graduated shape of the top, and holds up well.
• The fingerboard is ebony, because ebony holds up to decades of finger pressing without developing low spots.
• The tailpiece and the pegs can be made of anything, but ebony is the most traditional—maybe influenced by luthiers having leftover bit of ebony that were too small to use for fingerboards.