Getting John Henry and his hammer into a scientific paper

Gotta love a scientific paper that quotes John Henry stories. In Andy Ellington's primer on ribozyme evolution (PLoS Biology - Man versus Machine versus Ribozyme) he leads off with

The steam drill was on the right hand side,

John Henry was on the left,

Says before I let this steam drill beat me down,

I'll hammer myself to death”—The Ballad of John Henry (American, traditional)

His point here is to talk about man versus machine and to then discuss the recent article in PLoS Biology on a "Darwinian Machine" which I wrote about previously. (I think he is also making a bit of a play on words with the hammerhead ribozyme, but I am not sure). Anyway, Ellignton's article is worth checking out. I especially like the ending

Machine-based continuous evolution should be the best of all worlds, combining man's mental ability to chart the future with automated control of selection stringency with the still unpredictable mode and tempo of evolution's relentless drive.

Figure from Ellington's PLoS Biology paper. I can put it here because it is a fully Open Access paper using a broad Creative Commons license. All I have to do is cite the source. And so I am. Andy Ellington. PLoS Biol 6(5): e132 doi:10.1371/journal.pbio.0060132

Figure reportedly by Angel Syrett (see comments).