Back in the middle of last month, I had [a few things to say](http://scienceblogs.com/authority/2007/06/lets_talk_junk.php) about Casey Luskin (DI flak) and [his understanding](http://www.evolutionnews.org/2007/06/wired_magazine_unashamedly_mix.html) of so-called junk DNA. It's now the middle of the month again, and Casey is again [talking a lot](http://www.evolutionnews.org/2007/07/did_darwinism_hinder_colon_can.html) - and understanding very little - about "junk" DNA. [Larry Moran](http://sandwalk.blogspot.com/2007/07/casy-luskin-gets-it-wrong-again.html) has a post up where he tries to educate Casey about the fact that a hell of a lot of DNA is still, at least as far as we know, junk. I'm going to take a look at something a little bit different - one of the methods scientists use to identify areas of "junk" DNA that have important functions. It's a pretty cool way of doing things, but it's not one that Casey likes to talk about - because it's really one of the finest examples of how our understanding of Darwinian evolution has lead to new discoveries about living things.