From both parents, Zechariah his father and Elisabeth his mother, John was a Levite. He was from Aaron's line, yet not one acknowledgement is made regarding John having any tie at all with the already-installed system of Temple worship.
God miraculously caused John's conception and birth, even as He did Isaac's and Jesus'. Jesus' conception in a virgin woman without the involvement of a human male is an exception. Isaac and John's conceptions were normally produced except that Sarah and Elizabeth were beyond childbearing age.