Does my stepson’s bio father have to consent to his adoption?

I married my wife 5 years ago and she had a 7 year old son. At the time, he was still having contact with his father. As time passed, they saw each other less and less and for at least the last 2 years, they haven’t seen each other at all. My stepson and I have grown very close and he has been asking me to adopt him, which I want to do. My wife is in full agreement. If his father hasn’t been around and my stepson and his mother want me to adopt him, does his father have to consent? I’m not even sure at this point that we would even be able to locate him. If we can’t locate him, can the adoption go forward after a certain period of time?