Complex sentence: At the time the family thought Allan would only be gone two years; instead he stayed at Berkeley for 35 years, gaining his PhD in 1961 under the direction of Arthur Pardee, and setting up one of the world's most creative biochemistry labs.
Split into simpler sentences: At the time the family thought Allan would only be gone two years. Instead, Wilson eventually stayed at Berkeley for 35 years, gaining his PhD in 1961 under the direction of Arthur Pardee, and setting up one of the world's most creative biochemistry labs.