"The United States and Great Britain are two countries separated by a common language." So goes the old chestnut commonly attributed to playwright George Bernard Shaw. One of those separations is in the spelling of words like color (colour), theater (theatre), and realize (realise). But how did this separation occur?
If you want to see an evolutionary dead end, look no further than the supermarket produce aisle. Every banana you eat is an infertile clone, and its wild ancestors weren't much better when it came to finding new genes.