As organizations continue to invest heavily in Information Systems (IS) to support business processes, the under-utilization of such IS is a key concern that challenges efforts to exploit its benefits. What is most desirable is for users to engage in forms of deep use that effectively leverage the features of the IS for work tasks. But, too often users minimize their interactions with the IS. Yet for users how they use an IS often changes over time to become progressively deeper as the IS is embedded more in the performance of various tasks. To understand how IS use changes over time, this research-in-progress paper draws on principles of evolutionary change, that is, Generalized Darwinism, and reports the findings from a series of case studies.