In this excerpt from “Jefferson Fathered Slave’s Last Child,” published in Nature on November 5, 1998, Eugene A. Foster and his coauthors explain the results of a DNA test that concluded that a Jefferson male (and possibly Thomas Jefferson himself) fathered Eston Hemings, the last son of Sally Hemings. DNA from Field Jefferson, a paternal uncle of Thomas Jefferson, was compared with the descendants of Eston Hemings and Thomas Woodson, another putative son of Sally Hemings. Foster’s coauthors are M. A. Jobling, P. G. Taylor, P. Donnelly, P. de Knijff, Rene Mieremet, T. Zerjal, and C. Tyler-Smith. Reprinted by permission from Macmillan Publishers Ltd: Nature, 1998.