If you visit Google today, on Abraham Lincoln’s birthday, you will see a Google logo for Charles Darwin. Here is the logo, which links to a Google search for charles darwin:
It is also Charles Darwin’s birthday and I guess Darwin, the father of evolution, is more important than one of the most important US Presidents of all time, Abraham Lincoln. How did Google pick Darwin over Lincoln? Who knows – but they did. Personally, I am glad I did not have to make that choice.
I guess the easier solution would be to rotate between two logos, but Google didn’t go that route.