An accepted premise in genealogy is that if you share a surname you must also share a common root. If only you can connect the path to that root you will have genealogy nirvana. For many who share the same surname, this may be correct. However, for many of those with Welsh descent this is not the case.
Many factors have a role in this phenomena, and it has produced a great deal of bewilderment among those Jones surname tree climbers. This is especially true for those DNA folks who expect to have their test results reveal that straight line of descent. Of course, it is much more complicated, and a full picture of seeking you "Adam" Jones has many twists and turns. Well anyway, this post presents the fact that there is no single "Adam" from which the Jones surname has its root. On the most part, those who have the surname JONES will share that DNA [Y-chromosome] from other surname groups. What a deal...your family tree [through the male line] may be the same as a Williams, Owen, Evans, David, Morgan, Price, Lloyd, Jenkins, Ellis, Thomas, and others that follow a different route to their own "Adam".
P.S. For those whose Y-chromosome matches another surname, please identify yourself and which surnames are involved.