Darwin was the grandson of the great potter Josiah Wedgwood.
He married his first cousin, Emma Wedgwood, who was also a grandchild of Josiah.
Before marrying, he listed the pros (nine items) and cons (13 items) of such an action.
Item three on his 'marry' list was: "Object to be beloved and played with. Better than a dog anyhow".
The last item on the 'not marry' list was: "Perhaps my wife won't like London; then the sentence is banishment and degradation into indolent idle fool."
Darwin pointed out that lice which move from Hawaiians to English sailors die within a week.
His publisher, John Murray, suggested that Darwin should put more about pigeons into the Origin of Species, because everybody is interested in pigeons.
Darwin was born on the same day, 12 January 1809, as Abraham Lincoln.