When wolves returned to Yellowstone

Everything changed.

https://www.youtube.com/watch?v=ysa5OBhXz-Q#t=136

A great story but others disagree.

https://strangebehaviors.wordpress.com/2014/03/10/maybe-wolves-dont-change-rivers-after-all/

And then in the comments they quibble over the words “elk” and “deer.”