3E is clearly an evolution of AD&D, not OD&D.
I disagree.
-D&D 3e has a skill system much closer to the RC rules than AD&D non weapon proficiencies
-The D&D Companion set introduced the first prestige classes, the Druid, Paladin, Avenger, and Knight, accessible to higher level charcters. The AD&D1e bard was similar, but dual classing was very different than modern multiclassing and prestige classing.
-Max hit points at first level comes from the Basic DM book.
-Unified weapon damage; AD&D had different weapon damage for larger and smaller opponents.
-D&D 3e uses a Basic initiative system, not AD&D "count down" and certainly no weapon speed.
-No sub classes.
-RC D&D went all the way up to level 36, and offered very advanced versions of dragons and other creatures. AD&D petered out in the teens, offering tables only up to 20th level. Hence, while 3e follows AD&D in form, it is more like RC D&D in that extraordinarily high level play is supported.
-All classes are one HD per level.
-Many feats are lifted from high level fighter options, such as Power Attack/Haymaker.
- Ability score modifiers significant even at modest scores.
3e has a number of similarities to AD&D:
-Separate race and class.
-Ability score modifiers for race.
-Many prestige classes are similar in implementation to AD&D Kits.
-Some of the feats are lifted from Powers & Skills options.
-Nine point alignment system and larger cosmology.
-Existence of specific deities.
-Inclusion of paladin, bard, and druid base classes.
Then there are a number of new features:
-Unified d20 mechanic.
-Assumption that multiple skill points would be spent on skills.
-Feats for everyone.
-Three saves.
-Positive AC.
-9th level cleric spells.
-5' battle grid
I think it is far from clear that D&D 3e is just another edition of AD&D. To me, AD&D was in many ways a sideline full of fiddly bits. D&D 3e is essentially a new game, which borrowed many of its major structures from AD&D along with an AD&D-like assumed world, but still strongly related to the RC material as well. It is most AD&D like in that it has the 9 point alignment system and the Great Wheel, rather than three alignments and no outer planes.