So far I have not found any of the surnames in my family on any trees of my many (about 100) AncestryDNA matches. I was told by someone from Ancestry support that this may be due to non-parental events. I know my parents are my biological parents and am pretty sure that their parents are their biological parents as well. Assuming for now that there are no non-parents events going back to my grandparents, why can't I find any of the surnames from my family in my AncestryDNA matches' family trees? Thanks in advance for your help!