[mathematicaster]

I also find myself intuitively in the camp of your alternative theory.

Nevertheless I have an off the cuff comment to your question: Dune genetic memory is outside the bounds of our most basic understanding of inheritance because we do not know of any obvious mechanism to encode those memories into gamets in "one shot" (from direct experience to immediate offspring). Compare this with a very long arc over which a gazelle is born with brain initialized so carefully that it can learn to walk instantly, effectively having something that really looks like "genetic memory" of how to walk.

My confused ramblings aside, this to me suggests that it is at least plausible that such commonality among apes and homo exists. Now, providing evidence for it is quite a different ball game ...