The iPhone was released in June 2007. At that point, the iPod models were Classic (click-wheel), Mini (click-wheel), Nano (click-wheel), and Shuffle (screenless).
The first iPod Touch wasn't until September 2007, 3 months after the first iPhone.
When the iPhone 1 was released, the iPod range didn't have much on any other MP3 player. All the things that make an iPhone an iPhone - the touch-screen, multi-touch, iOS, didn't come from the iPod.
Perhaps iPod to iPhone wasn't quite 0 to 1, but it wouldn't have been much more than 0.001 to 1.