There is no way of knowing whether or not a rock had some of the by-product (daughter) element in it to begin with. Evolutionists must believe rocks did not have any of the daughter element or their dating process becomes worthless. Actually the reverse has been shown to be the case. By-products such as lead have been shown to exist in rocks where uranium never existed. Even evolutionary scientists concede this possibility. Evolutionist David Seidemann points out regarding another the potassium/argon