Complex sentence: In 1970, the family moved to Toronto where Layton graduated the following year from York University with a Master of Arts in political science; and later in 1983, he completed his Doctor of Philosophy in political science at York.
Split into simpler sentences: In 1970, the family moved to Toronto where Layton graduated the following year from York University with a Master of Arts in political science. In 1983, he completed his Doctor of Philosophy in political science at York.