Hi Eddie,
If you are on an open profile, you can use the drop-down list and click "Activity Feed". This will list who did what when. Their names are links to their profiles. If you click on what they did it will show you the specific changes made in a side-by-side format. Here is the activity-feed for Bill Pike as an example:
http://www.wikitree.com/index.php?title=Special:NetworkFeed&who=Pike-2312
I hope this is what you were looking for :)
Hi Eddie! Welcome to our one worldwide family WikiTree!
I am not sure I have the question down, but here is my answer. You can check the Changes tab to see what edits have been made by when and whom.
The Acknowledgements section of the biography can be an easy way to see who has contributed to a profile, but it is not required and does not show a what was changed or when. Please read this page for more info on Acknowledgements: http://www.wikitree.com/wiki/Acknowledgements