Earth (Earth-33⅓)

A version of Earth existed in Earth-33⅓, and had a similar, but distinctly different, history to that of the Doctor's universe. (COMIC: The Bits We've Missed So Far, etc.)

Early history
Earth first came into existence at some point after the Big Bang. After the planet formed, the earliest forms of life looked like "pink, globulous sprogs of jelly". When the Sixth Doctor took Peri Brown back to this point, she accidentally stepped onto the earliest form of life, essentially throwing away 50,000,000 years of evolution, causing the Doctor to realise the History Tour would take longer than they thought. (COMIC: In the Beginning)

More to be added