An Easement to Yourself
In some necessary situations it is practice to describe an easement (or rights of ingress and egress) and reserve those rights to be dedicated to future estates at the time a conveyance is made. I have even seen these filed of record even though they "technically" don't exist until title to the dominant estate is conveyed. And in a few cases I have seen title companies act as if the easement exists since it will probably exist in possibly the near future.
Merger of title is usually applied in the reverse of how it is being discussed here. Usually it comes up in situations like this:
1. A landowner owns a parcel that is served by an easment across another's land.
2. The landowner acquires the servient parcel.
3. The two parcels become owned by two separate owners.
4. The owner of the servient parcel sues to eject the owner of the dominant parcel.
Now, this us just conjecture becasue I've never seen a case addressing it, but I would think that if the landowner recorded an easment across his own land, thus entering it into the chain of title, and then sold a portion that would become the servient or the dominant parcel, a court would find that regardless of the technicality of the law, the intent was clear to make one parcel subject to the easment, and let it stand.
In California subdivision maps can't create private easements. They can dedicate easements to the public in the owner statement.
Suppose you have a two lot Minor Subdivision (called a Parcel Map in most counties). Parcel 1 depicts a 20' easement to Parcel 2. Normally Parcel 1 would convey with a reservation of the easement or Parcel 2 would convey together with the easement.
Further suppose through oversight Parcel 2 conveys forgetting to mention the easement, does it automatically come into existence since it is shown on the map?