If you consider rotary motion as wheels, there are some bacteria that have flagella that rotate to propel itself, complete with molecular bearings. That said,

If you consider rotary motion as wheels, there are some bacteria that have flagella that rotate to propel itself, complete with molecular bearings. That said, biological evolution tends to get stuck on local maxima very easily (see convergent evolution of eyeballs), and wheels are kind of hard to evolve because of the difficulty of making large bearings biologically. Not to mention wheels kind of suck unless you're on pavement (look at tanks, etc)