A bacterial flagellum acts as the outboard motor on a bacteria. But is the complex arrangement of parts that enable it to do its job a result of design or evolution? Michael Behe first opened the debate on the ‘irreducible complexity’ of biochemical machines in his 1996 book Darwin’s Black Box.

Intelligent Design proponent Jonathan McLatchie and theistic evolutionist Keith Fox debate whether Behe’s theory has stood the test of time, the bacterial flagellum and whether ID is a science stopper or theologically helpful.