Page Versions Explained
Each Wiki page automatically keeps track of past versions.
Anytime the content of a page changes, a new version is generated, and a new entry is generated in the Page History.
Version entries always show you the version number, and when it was generated.
While the version entry itself does not tell you who created the version, you can ascertain that by looking at the history entry right before the version, which shows you who edited the page, which in turn tells you who is responsible for generating this version.
note:
Attachments, comments, permissions, and labels generate history entries, but do not generate new versions of a page.