Copy/paste in new layer
Copy an object (cmd + c) then create a new layer and paste it in place in the new layer (copy in place in new layer)
Egor Chistyakov commented
Rafe, can you explain it a bit more?
It does work for me alright: copy in one layer, then create a new one, then paste (both default and in place).
You mean you want Ai to create a new layer for you?