In some of their papers, the second generation Chicago economists Gordon Tullock, Gary S. Becker and Jack Hirshleifer explicitly forge a link with evolutionary biology. h is chapter discusses these papers. I am interested mainly in two issues. One is whether these papers are in any way related to the so-called selection arguments that Alchian (1950) and Friedman (1953), as key exponents of the first generation of the Chicago School of economics, advanced earlier (Vromen 1995). Do the papers build on the selection arguments, for example, or are they completely unrelated? the second issue is what specii c forms the links forged with evolutionary biology take in the papers. In particular, what purposes are these links meant to serve? 1 Are they meant to contribute to an improved economic theory, to an improved biological theory, or to both of them?