From p.415 of The New York Genealogical and Biographical Record, vol. 47:
"Rev. Ralph (or Rodolphus) Thacher, b , 1649, about (his birth is not recorded, but, in the will of his grandfather, Rev. Ralph Partridge, he was styled second son of his mother; he was made a freeman of Duxbury in 1670 and assuming him to have been 21 years old he must have been born about 1649), at Weymouth (or Duxbury), Mass.; d. July 26, 1733, at Groton, Conn., where he was buried in what is known as Rose Hill Burying Ground, gravestone; m. Jan. 5, 1669-70, at Duxbury, Mass., to Ruth Partridge (dau. of George and Sarah (Tracy) Partridge of Duxbury, Mass.), b (no record of her birth), at Duxbury, Mass. (probably); d. Oct. 30, 1717, at Lebanon, Conn., and was probably there buried, no gravestone.
"Res. Duxbury, Mass., Chilmark, Mass., Lebanon and Groton. Conn.; Freeman, Duxbury, 1670; constable there as early as June 3, 1673, and as late as 1678; Town Clerk there 1684-1694; he was ordained sometime previous to Feb. 13, 1694, and made minister at Chilmark, Mass., and remained there until 1714 when he resigned his charge and removed to Lebanon, Conn., where he probably lived with his children who had preceded him there; after his wife's death in Lebanon he removed to Groton, Conn., and made his home with his daughter, Lydia, the wife of John Dean. In the latter years of his life he was totally blind."
Children, 9 (Thacher):
Rodolpbus (or Ralph),
Marriage: 11 MAY 1643, Duxbury, Massachusetts
Alternate Marriage: 11 MAR 1643 Duxbury, Plymouth, Massachusetts
Thacher was the preferred spelling of the name at the time Ralph was born and for at least 2 or 3 generations following. In some lines, especially in New England, the spelling remains Thacher. The name did NOT originally come from the occupation of thatcher, as in thatching a roof, but grew to be spelled that way, because it was a familiar word in English. See the footnote at the bottom of page 4 in Genealogy and Biographical Sketches of the Descendants of Thomas & Anthony Thacher'.
It may be possible to confirm family relationships with Ralph by comparing test results with other carriers of his Y-chromosome or his mother's mitochondrial DNA.
However, there are no known yDNA test-takers in his direct paternal line.
Mitochondrial DNA test-takers in the direct maternal line: