Saber N. Elaydi is Professor of Mathematics and the department chair at Trinity University in San Antonio, Texas. His main objectives in teaching is to make mathematics accessible to all Trinity students regardless of their background or academic focus. His UTM entitled An Introduction to Difference Equations is in its 3rd edition with Springer. Jim M. Cushing is Professor Emeritus of the Department of Mathematics at University of Arizona. His research involves the derivation and analysis of mathematical models that describe population and evolutionary dynamics. Professor Cushing is particularly interested in structured population dynamics and also studies evolutionary game theoretic versions of population models.