But the evolution isn’t necessarily the important part, it’s the two parts having separate development processes in modern day humans that is notable.

> I think "Human brain evolved from two separate organs" would've been more accurate and sufficiently simple/short for a headline, but I guess it won't fly either due to political reasons.

I don't agree. For that you need to distort the definition of what an organ is to comply the requirement for two separate organs with distinct origin, genetic, and biochemical traits, and different function and responsibilities to somehow remain classified as the same organ.