Evolution of Mickey Mouse

Mickey Mouse has evolved. This was noticed and brough to the world by Stephen J. Gould in his book, "The Panda's Thumb", deserving a whole chapter.
As you can see, in this case, Mickey Mouse is not portraited as an individual, but as a population, or species of consecutive Mickeys. The Mickeys started to suffer small changes and, since they were successful (the character became more dear to the public) they kept those traits, by a special kind of natural selection.

And what traits are those that make Mickey each time more a favourite of people? The traits of a child! The chubby, big eyed, big headed, rounder mouse has been becoming everytime more like the being we instinctively tend to love and protect: our kids.

Stephen Jay Gould

Jay Gould was a notable paleontologist and a really famous scientific divulgation writer. Most of his books talked about evolution and showed some of the more fascinating examples.
His most important contribute to this science was the Theory of Pontuated Equilibrium, a line of thinling that, diferently from gradualism, defends that short periods where many evolution steps occour are separated by long peroid where only a few happen.
Some of his books, like the "The Panda's Thumb" or "Eight Little Piggies" are still being edited after decades.

John Maynard Smith

Maynard Smith was a british evolutionary biologist which greatest achievement was the introduction of Game Theory to evolution, having also worked on the evolution of sex and, more recently, signalling theory.
Maynard Smith was an unconventional professor for his time, trully dedicated to young resserchers and helping them develop their works. The only one he could not help was Hamilton, student in the same college. Hamilton was so afraid that someone would steal his work that he didn't try to find help.