Haldane, Mayr, and Beanbag Genetics presents a summary of the classic exchange between two great biologists - J.B.S. Haldane and Ernst Mayr - regarding the value of the contributions of the mathematical school represented by J.B.S. Haldane, R.A. Fisher and S. Wright to the theory of evolution. Their pioneering contributions from 1918 to the 1960s dominated and shaped the field of population genetics, unique in the annals of science. In 1959, Mayr questioned what he regarded as the beanbag genetic approach of these pioneers to evolutionary theory, ""an input or output of genes, as the adding of