Claims of mathematical disproof of evolution typically make use of probability theory. The idea is to show that it so improbable that a given complex biological structure, such as the vertebrate eye, could have evolved gradually that it is effectively impossible for it to have done so. Frequently this argument will include actual calculations purporting to place the assertion on a rigorous mathematical footing.As a professional mathematician, I am well aware of how impressive such calculations can appear to people untrained in probability.
http://www.csicop.org/creationwatch/probability-one.html