In a similar manner a number of common Welsh surnames are derived from the mutation caused by the 'son of' prefix 'ap / ab'
BOWEN is derived from ab Owain / Owen, POWELL from ap Howell / Hywel, PROBERT from ap Robert, PUGH from ap Hugh, PROBYN from ap Robyn, PREECE or PRICE from ap Rhys / Rees and PARRY from Ap Harri / Harry. There are probably more...