In Michael J., Jr. v. Michael J., Sr., 198 Ariz. 154, 156, P 7, 7 P.3d 960, 962 (App. 2000), a member of the Tohono O'odham Nation filed a successful lawsuit to transfer a dependency proceeding involving an Indian child to tribal court. 198 Ariz. at 155, PP 1-3, 7 P.3d at 961. The guardian ad litem appealed and challenged ICWA's application because the father had not "established legal paternity." Id. at P 11. The Court upheld the transfer even though the putative father had not filed a paternity action because he acknowledged paternity, which was later confirmed by DNA testing, to the juvenile court. Id. at P 12. Moreover, the father's tribe provided written confirmation that he was enrolled in the tribe and the child was eligible for membership. Id. The Court found that his acts were sufficient acknowledgement, even though a formal paternity petition had not been filed, and, as a result, ICWA applied. Id. ("The Act merely requires a putative Indian father to acknowledge or establish paternity . . . and the record contains ample evidence to support the trial court's finding that father is a 'parent'"). While the father in Michael J. timely "acknowledged" his paternity, the putative father in Juvenile Action No. A-25525 did not. 136 Ariz. at 532, 667 P.2d at 232. There, despite repeated notices, the putative father, a Pima Indian, did not acknowledge that he was the child's father until the child was three years old, and thirty-one months after the adoption. Id. Although he was notified of the termination proceedings and needed only to acknowledge that he was the father, he remained silent. Id. ICWA requires "more than mere speculation of paternity" and the father's acknowledgment some thirty-one months after the adoption was too late to invoke the Act. Id. at 232-33, 667 P.2d at 532-33. Thus, we held that a finding that a child is an Indian child does not relate back to the child's birth, and, as a result, ICWA does not apply to earlier proceedings. Id.