Does a Pokémon's potential CP bar scale linearly?

Does the semicircular potential CP bar scale linearly? At my current level, if the bar scales linearly, this Fearow's CP would cap around 500. This is significantly lower than my highest CP Pokémon, and therefore I wouldn't bother trying to upgrade it.

Edit

I'm not asking what the bar represents; I understand that it represents the Pokémon's overall potential CP at my current level. What I'm attempting to determine if this bar scales linearly or not. Understanding how the bar scales could help to project the potential CP of a Pokémon to determine if it's worth the effort of upgrading it or if it will cap before it surpasses the CP of other Pokémon you already have.

The semicircular bar behind a Pokemon is, in fact, linear.

The lower end of the bar represents some (still unknown) value dependent on the family of Pokemon, and the upper end of the bar represents that Pokemon's current CP cap at your level.

I went ahead and proved the linearality of the semicircle using GIMP. You may see the results here. Note that there may be some error in the numbers due to inaccuracy of my tests (things may not have been lined up quite right).

^(source)