The paternal relationship between Charles Allen Harvill and his son
Isham Andrew Harvill is confirmed by the direct inheritance path of autosomal DNA down to their DNA tested descendant BA.
The segmental (via DNA segment triangulation) and total DNA shared between BA and other confirmed descendants of
William Harvill/
Barbara Sally Ollis is consistent with the expected ranges for their respective relationships. Since BA descends from William Harvill/Barbara Sally Ollis through Charles Allen Harvill and his son Isham Andrew Harvill, the presence of significant shared DNA between BA and other known descendants of William Harvill/Barbara Sally Ollis validates the generational links along this paternal line.
This supports the conclusion that DNA was passed from MRCA couple William Harvill/Barbara Sally Ollis through Charles Allen Harvill to Isham Andrew Harvill, and ultimately to BA, confirming this direct ancestral connection through multiple generations.