California Code, Family Code - FAM § 7664

(a) If, after the inquiry, the biological father is identified to the satisfaction of the court, or if more than one man is identified as a possible biological father, notice of the proceeding shall be given in accordance with Section 7666.  If an alleged biological father fails to appear or, if appearing, fails to claim parental rights, those parental rights with reference to the child shall be terminated.

(b) If the biological father or a man claiming to be the biological father claims parental rights, the court shall determine biological parentage.  The court shall then determine if it is in the best interest of the child that the biological father retain parental rights, or that an adoption of the child be allowed to proceed.  The court, in making that determination, may consider all relevant evidence, including the efforts made by the biological father to obtain custody, the age and prior placement of the child, and the effects of a change of placement on the child.

(c) If the court finds that it is in the best interest of the child that the biological father should be allowed to retain parental rights, the court shall order that the biological father's consent is necessary for an adoption.  If the court finds that the man claiming parental rights is not the biological father, or that if the man is the biological father it is in the child's best interest that an adoption be allowed to proceed, the court shall order that the consent of that man is not required for an adoption.  This finding terminates all parental rights and responsibilities with respect to the child.