In the case of point in time database it is best to have combination of surrogate and natural keys. e.g. you need to track a member information for a club. Some attributes of a member never change. e.g Date of Birth but name can change.
So create a Member table with a member_id surrogate key and have a column for DOB.
Create another table called person name and have columns for member_id, member_fname, member_lname, date_updated. In this table the natural key would be member_id + date_updated.
