A common criticism of natural selection is: How can it produce novel complex useful structures by pure random chance? Darwin argued that selection is not a random process, and furthermore, it is cumulative. This lesson provides a way for students to actually compare the cumulative non-random selection of Darwin with the non-cumulative version so often erroneously implied. Students attempt to produce a full sequence of 13 cards of one suit (ace – to king). This must be done by shuffling the suit of cards for each round, then checking the cards. Half the teams must look for the full sequence each time, and repeat the process until this is accomplished. The other teams start to build their sequence by pulling the ace when it first appears as the top card, then adding to the stack whenever the next card for the sequence is shuffled to the top. Discussion reveals how the second method mimics Darwinian natural selection, while the first does not.