Complex sentence: The breadth and number of varieties of muscat suggest that it is perhaps the oldest domesticated grape variety, and there are theories that most families within the "Vitis vinifera" grape family are descended from the Muscat family.
Split into simpler sentences: The breadth and number of varieties of muscat suggest that it is very old, perhaps the oldest domesticated grape variety. There are theories that most families within the "Vitis vinifera" grape family are descended from the Muscat family.