Complex sentence: Orgel believed that the process of aging arose due to mutations acquired during the replication process and Kirkwood developed the Disposable Soma Theory in order to mediate Orgel's work with evolutionary genetics.
Split into simpler sentences: Orgel believed that the process of aging arose due to mutations acquired during the replication process. At the time, Kirkwood developed the Disposable Soma Theory in order to mediate Orgel's work with evolutionary genetics.