I downloaded my ancestral tree from Ancestry to family search, and I found profiles of ancestors I did not add, how am I to know if this is correct, and how are these new people in my tree?
The FamilySearch tree is collaborative - meaning we all work on the same tree. It is not my tree or your tree. It is our tree, all of us, together.
When you uploaded your tree to the FamilySearch tree, others can see and work on any deceased ancestors, attaching sources, making changes they believe are appropriate, etc.
You can evaluate the quality of the tree by checking to see how many sources are attached to each of the "new" people. Then open the sources and examine them in detail. Basically, you follow the same process that you would in building a tree on Ancestry.
Dear Aine Ni Donnghaile,
thank you for clarifying this for me, I now understand better how this works.