Behold – the only known example of a biological wheel. Loved by creationists, who falsely think they are examples of “intelligent design”, the bacterial flagellum is a long tail that is spun like a propeller by nano-sized protein motors.
Now these wheels and their gearing have been imaged in high resolution and three dimensions for the first time. Morgan Beeby and his colleagues at Imperial College London used an electron microscope to resolve the mechanisms that provide different amounts of torque to the motors.
The motors are diverse, coming in a wide variety of shapes, sizes and power outputs. Indeed, the diversity of the motors and the fact that they have evolved many times in different bacterial lineages, scuppers the creationist view that the machinery is “irreducibly complex”.