I believe they are all from the same genetics but have become different by adapting to different geographic areas and environments.
The naga jolokia is a term used for all the dorset,Naga Morich,Bhutt/Bih, as well as the Pc-1. Before all these varieties were discovered in this part of the world, the mysterious super hot peppers from India and Bangladesh were all considered Naga Jolokia(jolokia just means pepper). Now 4 or 5 years later we have narrowed it down to different variations and people are still using the Naga jolokia term thinking there is another extremely rare pepper.
Even if DNA testing is done, it may only prove that these peppers have the same genetics but plants have a remarkable ability to adapt and mutate, and this is likely what has happened over many years.