To accurately answer your question I would need powers of divine knowledge. Your question falls into the category of, "Which came first, the chicken or the egg?"
By definition dubstep is a form of dance music, typically instrumental, characterized by a sparse, syncopated rhythm and a strong bassline*.
Instrumentation is achieved through the use of a sequencer, turntables, a sampler, drum machine, a synthesiser, a keyboard, and even personal computers.
The origins of dubstep's style can be credited to 2-step garage, breakstep, dub, drum and bass, techno, grime, reggae, and old-school jungle.
In truth, the early UK versions of this genre of music are easily traced to Jamaican party music.
In 1998, the first commercial releases of dubstep occurred in the UK. The most prominently recognized artists are El-B, Steve Gurley, Oris Jay, and Zed Bias.