How to get a static author on a wiki

Whenever someone edits a wiki from the front end, the author is automatically changed to them. However, when you edit from the backend, the original author remains and it shows that you were the one who made the most recent changes.

We’d like the original author to remain always. The backend shows who has done editing and when, but the author is always changed when that editing is done on the front end.

My site is here: http://ischoolwikis.sjsu.edu/lispublications/ and wikis are all under ‘publication profiles’.