According to the Oxford English Dictionary, twerking predates Miley Cyrus by 150 years.
This of course has come as no surprise to me: I do believe that Charles Dickens first wrote about twerking in A Tale of Two Buttocks, back in 1859...
"I revere the memory of that night. I had imbibed of a vast quantity of ale and, my tolerance for alcohol not being what it once was, started twerking like a mutha-fornicater on the bar counter at 'The Three Cripples' tavern. Forgoing the chains I normally wear in life, I shook that booty until my buttocks were but a diaphanous blur.
It was the best of times, it was the worst of times."
-Charles Dickens
(as told by Kevin Ansbro).