"" The apostles had their own disciples who preserved the teachings, and the gospels emerged from this setting. ""
I would say with the exception of Mark, the apostles had disciples who had disciples ect. More degrees of seperation. Also, some of the Gospels were based on one and other.
It's just a common misconception, kind of like Mary Magdeline being a whore. I wouldn't adhere to the school of thought that she was Jesus' wife, but she wasn't a whore.
Let's say I want to preserve memories of my great grandmother.
Sometimes I manage to write them in a journal. Sometimes I tell my children a story about her - and then THEY write down the story I told them - or they pass it on orally to their children.
Someday my grandchild or great grandchild compiles these writings and oral stories into an organized portrait of granny.
Who is the author? Where did the memories come from?