My Linguistics professor said this in class during lecture. They asserted that the Phonecian alphabet is the ancestor to all modern alphabets and that the idea spread from there. Any alphabet in use today can be traced back in some from or another as a modification of the Phonecian alphabet. Is this true? If not, what alphabets aren't derived from the Phonecian alphabet?
Well, it all depends upon your definition of alphabet. The Japanese have an alphabet-like system, though it's really a syllabary since each character represents a syllable. That was based on the Chinese system of writing. The Chinese system has no relationship to Phoenecian writing. Likewise, Hangul is the Korean system of writing, and it was based on the Chinese system of writing, but became completely different and is also a syllabary (but completely different from the Japanese syllabary). There is also a system of writing that was used in Central America, but that's not an alphabet. And there's ancient Egyptian, but that's not an alphabet, either.