Richard Weisenberg, biologist at Temple University, wrote an open-letter to Wells in the Philadelphia Inquirer noting "Evolution by natural selection and the origin of life are entirely different subjects. ... The validity of any particular theory of biological origins (and there are several) has no relevancy to the well-established validity of evolution by natural selection." He continued, "I can only conclude that you have failed to master even a fraction of the massive body of evidence supporting the principle of evolution by natural selection."