Clue: 'Predated' now 'pronated' because of this boffin (6)
Answer: EDISON
Explanation: 'Predated' now 'pronated' because of this boffin (6)
The **ED** of "prEDated"** IS** now **ON** when it's changed to "prONated" 
 
 
*For the purposes of the theme, I did a little research and Edison's son ran a company that made wooden puzzles and Edison himself lends his name to the "Light Filament" puzzle, which involves two small metal structures.