How the Bible got altered

I recently saw a Stanford University lecture on the errors introduced in the Bible (New Testament) in its two millennium long journey since Jesus' time. Its absolutely worth the 50 minutes of your time.

One of the significant errors that deserves a mention...

The Gospel of Mark originally ends thus... Mary and some women go to the tomb where Jesus is buried after his crucifixion only to find it empty. They find a man in white who tells them about Jesus' resurrection and his appearance at Galilea. He tells them to spread this news to disciples. However, the women ran away and told nothing to anyone.

"And they went out quickly, and fled from the sepulchre; for they trembled and were amazed: neither said they any thing to any man; for they were afraid"

And thats how the oldest copies of the Gospel of Mark end. However, it seems to be a somewhat abrupt and disconcerting ending, which is probably the reason that some scribe added the following lines to the ending (some bibles mark these lines to point out that they were not part of the original)

Now when Jesus was risen early the first day of the week, he appeared first to Mary Magdalene, out of whom he had cast seven devils. And she went and told them that had been with him, as they mourned and wept. And they, when they had heard that he was alive, and had been seen of her, believed not. After that he appeared in another form unto two of them, as they walked, and went into the country. And they went and told it unto the residue: neither believed they them. Afterward he appeared unto the eleven as they sat at meat, and upbraided them with their unbelief and hardness of heart, because they believed not them which had seen him after he was risen.
And he said unto them, Go ye into all the world, and preach the gospel to every creature. He that believeth and is baptized shall be saved; but he that believeth not shall be damned.
And these signs shall follow them that believe; In my name shall they cast out devils; they shall speak with new tongues; They shall take up serpents; and if they drink any deadly thing, it shall not hurt them; they shall lay hands on the sick, and they shall recover. So then after the Lord had spoken unto them, he was received up into heaven, and sat on the right hand of God. And they went forth, and preached every where, the Lord working with them, and confirming the word with signs following. Amen.

As always, comments are welcome.