Do you need biological father’s consent to adopt his child?

A friend of my husband and I from our church has a teenage daughter who is pregnant. She does not want to keep the child and we are very interested in adopting the baby. The mom-to-be does not have any contact with the biological father and does not even know where he lives at this point. There has never been a paternity test but she says she’s sure he is the father. If he’s never formally been identified as the father and she can’t locate him, do we need his consent to proceed with an adoption once the child is born? If we do, how do we go about finding him and what exactly does the consent need to say? We live just outside of San Antonio and she thinks he is possibly living out of state. Can a lawyer help us get the consent?