Performing mathematical operation on the y coordinates in a list of coordinates

I have a list that contains a set of coordinates in the form {{x1,y1}, {x2,y2}, …}. I want to edit the list in manner that it takes the log() of all the y coordinates only. Essentially, I want redefine the list such that it now contains {{x1,log(y1)}, {x2,log(y2)}, …}.