I don't get why people say James Blake is dubstep... he really is nothing of the sort, I don't even know what I'd call it... minimalistic downtempo/chill maybe?
Anyways, history lesson for you peeps from someone who was there

Dubstep originally came from UK 2-step garage, which came from 4x4 garage, which came from sped-up versions of NYC/Jersey deep house producers...
so basically it went something like:
To:
To:
To:
To:
To:
To:
and finally to: