Family Tree DNA Lincoln Surname Project
Known descendants of Thomas Lincoln the miller have tested and match each other. Known descendants of Samuel Lincoln the weaver have tested and match each other. By this we have Y-DNA results that represent these two lines. The results show that there is no relation at all.
Thomas the miller belonged to the G2 haplogroup; Thomas the cooper to the T haplogroup (same as Thomas Jefferson); and all other Lincolns who have tested belonged to the R1b group, which is the most common in Europe.
The results of testing of at least one descendant of each of the other immigrant lines also show that the Thomas the husbandman/Stephen Lincoln line is related to the Sgt. Daniel Lincoln line, back before the 1630s. None of the other paternal Lincoln lines from Hingham, MA are related to each other. There has been intermarriage of these lines, but they have all different Lincoln ancestors.
The lesson learned is that the surname represents that they probably all had ancestors who lived in the city or the shire of Lincoln in England, but at best they were neighboring families and not related.