Y-DNA is passed from father to son. Over generations there may be some mutations but if you can find someone with 0 or 1 mutations genetic distance, you will share a common ancestor. Traditional genealogy and other's Y-DNA is necessary to confirm.
I share 0 genetic distance and our MRCA (most recent common ancestor) is suspect to be Rees-1190.
My Rees brick wall will only be scaled through Y-DNA.
If you are or have a male relative with a Rees surname (or variation), would you ask them to take a Y-DNA test from Family Tree DNA?
https://www.familytreedna.com/products.aspx Y37 test cost $ 167. Autosomal + Y37 will get you both for $ 248. Results can be shared on the Y-DNA Surname Project and YSearch.
https://www.familytreedna.com/public/reese/default.aspx?section=ycolorized
DNA is all new to me but along with a paper trail will improve my searchesI