Roberson BigY Group Tree: https://discover.familytreedna.com/groups/clan-donnachaidh/tree?subgroups=24716 (best on computer monitor, select full screen)

Advances in YDNA Testing (BigY SNP Testing): https://blog.familytreedna.com/why-big-y-700/

lab tools to see notable and ancient YDNA matches: Matches for Roberson I-FT223253
I-BY101763 > I-BY78405 > I-FT223253 > I-FT224850 Roberson YDNA branches

Recently the lab released a new tool about the BigY results which covers ancient YDNA matches from archaeological remains.
Notable YDNA matches: https://discover.familytreedna.com/y-dna/I-FT223253/notable
Archaeological sites, matching YDNA: https://discover.familytreedna.com/y-dna/I-FT223253/ancient

Your current YDNA Haplotree (I-FT223253) YDNA is only passed directly from father to son. The BigY DNA testing has confirmed and matched Roberson/Robertson lines back to Scotland. Prior to the use of surnames the YDNA matches go back to Viking and Ancient times in Scandinavia.

This is the "story" about the results: https://discover.familytreedna.com/y-dna/I-FT223253/story
Aditional informational tabs on the left side of the page.

The only way to discover a complete YDNA from birth to ancient is to test two closely related males (father/son, uncle, cousin).

. https://pbase.com/daveb/roberson
162946 James Roberson b 1737 Scotland d 1828 Bledsoe TN Scotland I-FT223253

What is the BigY Test:
Janine Cloud, 2021, Family Tree DNA
https://www.youtube.com/watch?v=jiDcjWk4cVI

Robertson I1 Group AF- found in Edinburgh and Renfrewshire, Scotland
https://www.familytreedna.com/public/ClanDonnachaidh?iframe=ydna-results-overview (set page size to 5000)
https://www.clandonnachaidhdna.org/