[Right Wing Professor]

Gandharan culture is considered to be a fusion of Hellenism and Indian Buddhism. See, for example, http://www.caroun.com/Art/Pakistan/BuddhistArtofNorth-WestPakistan.html. Invasion of Turkic and Persian tribes came later. No one knows who descended from the inhabitants at that time, but culturally, there's no link.

[Cronos]

Culturally there's no link. Correct.

The present day inhabitants would have descended from them, only culturally adopted the invaders culture (as happened in Celtic France, Spain etc.)

You could say the same thing about Stonehenge