I just thought that ancestry.com should get it right according to most family beliefs, and that is most to all Yanceys/Yancys believe firmly that the name is inexorably tied to the family Nanney, which came from Wales in the middle 1600's, about 1640, with Governor Berkeley of Virginia, the Nanney/Yanceys being a group of four or five brothers. The name is of origin in the area of Dolgellau, Wales, where in the 12th Century the second son of Bleddyn ap Cynan, the Prince of Cynedd, Powys, and Deheubarth, set up his own estate, Nannau, and became the first Lord of Nannau, meaning in Cymraeg (Welsh) "of the brooks." So, he was Cadwgan Lord Nannau ap Bleddyn, Cadwgan "Lord of the Brooks." His estate is still there, now a bed and breakfast after passing out of the family with the line of the Vaughans. But most Yanceys/Yanceys and all Nanneys (having preserved the family name more thoroughly) believe him to be their descendant, and so the name is most certainly NOT of Dutch origin or a corruption of some wayward Jansen, but of Welsh origin. There has been much study done by a Dennis J. Yancey, and earlier work done by a welsh geneologist O. E. Ruck. And though there is no all-important and definite link between the two families, tradition and word of mouth and now much study has made the case very solid, if not entirely indismissible.
Just thought that should be cleared up, because ancestry.com has, unfortunately, got it wrong this time around (though they can be commended on even trying; the Yancey name is a geneologist's nightmare and has remained so for some time.)