Charles Darwin was a famous biologist and friend of the Sixth Doctor. (BFA: Bloodtide)
The Third Doctor also claimed to have met Darwin. (PDA: Island of Death)
The Seventh Doctor laughed at the idea that Darwin's theory of evolution was unproven. (NA: Human Nature)
Published Works
Behind the Scenes
David Tennant voiced Charles Darwin in the cartoon The Pirates! Band of Misfits.