I thought this time line of the Coke and Pepsi logos did a good job of visually explaining the challenges of adapting brand messages to changing consumer preferences in a highly competitive product segment. (Courtesy of the We Heart Branding blog.)

 

Some commenters thought the Pepsi evolution was adaptive and progressive. Others thought the changes by Pepsi strengthened Coke's market leadership and brand awareness.

Anyone think it would be interesting to create the same time lines for one or two leading healthcare provider brands and logos? What would be driving the evolution of healthcare provider logos?