Worldwide Genealogy: Asking Some Adoption Questions

A few days ago, I wrote a post about discovering the birth and death registration records for two sons adopted by Nathaniel and Anne "Annie" (Hutton) Muir. Those registration records answered several questions, but the ensuing research raised more questions!

Portion of Nathaniel Muir McGregor's birth registration
from ScotlandsPeople

During my follow-up research, I discovered that Nathaniel and Annie's other son was also adopted. How to think about that adoption and who might be his father are the questions I'm asking in my May 25th post on Worldwide Genealogy -- A Genealogical Collaboration. I hope you'll click over to read about my questions and provide your thoughts on what the answers could be.