Copies of copies of copies

This is a fascinating article.

But almost immediately, Ehrman ran into a problem. It was an intellectual problem at first, but it soon became larger and harder to quarantine. In one of the first classes he took at Moody, he learned that none of the original texts of the New Testament exist. All we have are copies, made years later -- usually, many centuries later. In fact, the copies are copies of copies, and they’re filled with errors or intentional changes made over decades or centuries by scribes. Burning with fervor to discover the true word of God, the authentic divine voice that had been obscured or changed by all-too-human writers, Ehrman decided to begin a serious study of the New Testament. He completed his undergraduate studies at Wheaton College, where he began studying ancient Greek, the original language of the New Testament. But there was still no answer to his original question: How could we know what the word of God was if all we had were error-riddled copies?
So Ehrman decided to plunge all the way in and immerse himself in the academic study of the texts of the New Testament. He entered the Princeton Theological Seminary, home to the world’s leading authority in the field, Bruce Metzger. His literalist faith in and his devotional approach to the Bible were under increasing strain, but he managed to hold onto them for a while -- until a professor jotted a casual comment on one of Ehrman’s papers. Ehrman was attempting to explain a passage from the Gospel of Mark in which Jesus refers to an event that took place “when Abiathar was the high priest.” The problem is that the book in the Old Testament that Jesus is referring to states that not Abiathar but his father Ahimelech was the high priest. Ehrman came up with a convoluted argument to reconcile the contradiction, using Greek etymology to prove that Mark did not mean what he apparently said. Ehrman believed that his professor, a beloved and pious scholar named Cullen Story, would appreciate his argument as a fellow believer in biblical inerrancy.
Story’s response, Ehrman wrote in his best-selling 2005 book “Misquoting Jesus,” “went straight through me.” “Maybe,” Story scrawled at the end of Ehrman’s paper, “Mark just made a mistake.”