I'm a level 65 Viscanti Geomancer. If I reincarnate into a Human, will the stat increases brought on by Evolution go into effect for the past 15 levels? Since it is based on the archetype, will it just assume I've been a Geomancer since level 50?

Yes.

Whee, thanks.

Also, if you reclass, you probably get stat changes.

I'd assume so.