No express devise, bequest, or conveyance of an estate for life, or other limited estate in real or personal property shall be enlarged or construed to pass any greater estate to the devisee, legatee, or grantee thereof by reason of any devise, bequest, or conveyance to the heirs, heirs of the body, children, or issue of such devisee, legatee, or grantee; but this section shall not in any manner or under any circumstances be so construed as to impair or affect the vested rights of any person in or to any lands or estates acquired prior to July 4, 1907.
Iowa Code § 557.21