A short article which offers an excellent classroom strategy to help students resolve the all-to-common confusion of Lamarck's mechanism for evolution with Darwinian natural selection. I, too, have encountered this widespread problem regularly: students explaining evolution by natural selection by using phrases e.g. "organisms adapt by changing their structures of behavior in order to survive", suggesting that the changes individual organisms undergo provide the underlying mechanism of natural selection, a clear confusion of Lamarck's ideas with Darwin's.