Basically what constitutes daddy meaningfulness is being involved (mindful parenting), and not just being the biological father (genetics). Being involved should take precedence in having a say in a child's life.
Wow. Really. Who were the scientific geniuses who concluded this? In all fairness the legal system has favored biology when it comes to custody wrangling.
I haven't seen my biological father since I was 13. By choice. I remember standing in front of a judge and telling him I didn't want to see him. And over the years he has never reached out to me since (nor have I to him) or tried to have a "say" in my life since.
I've let go of that baggage decades ago, and this isn't about we did or didn't do, or what we never worked out as adults – my point is, if something had happened to my mother while I was under the age of 18, would the legal system have given my biological father the edge over my step-father, just because of biology?
I truly hope not, but I'm sure if I did some research I'd find out a whole bunch of similar father custody scenarios that played out for the chromosomes instead of a loving dad.
There are "growing fathers' rights concerns" all over the world and fortunately it looks as though nurture trumps nature more often these days in the human world.
The same should apply to mothers as well. But that's another post for another time.