Karlin,
the web page you copied from is nothing to do with Darwins theory of evolution. Instead it is about RNA (biology) and talks about a system called SELEX (systematic evolution of ligands by exponential enrichment). Basically:
"In vitro selection, or SELEX, is a technique that allows the simultaneous screening of highly diverse pools of different RNA or DNA (dsDNA or ssDNA) molecules for a particular feature" (see web page linked below).
Note that the author here uses "In vitro selection" as a synonym for SELEX, where as in the web page you quoted the author uses the term "In vitro evolution".
Whatever name you use, this technique has absolutely nothing to do with Darwins theory of evolution. The usage of the word evolution here is in its general sense - i.e. denoting change over time.
If you are going to use google, at least intelligently filter the results.