Haldane's Dilemma

Haldane's Dilemma refers to a limit on the speed of beneficial evolution, first calculated by J. B. S. Haldane in 1957, and clarified further by later commentators. Creationists, and proponents of intelligent design in particular, claim it remains unresolved. Contrary to creationist claims, Haldane's dilemma is of no importance in the evolutionary genetics literature. Today, Haldane's Dilemma is raised mostly by creationists opposed to evolution, who claim it is evidence against large-scale evolution, and a supposed example of negligence on the part of the scientific community.

Haldane stated at the time of publication "I am quite aware that my conclusions will probably need drastic revision", and subsequent corrected calculations found that the cost disappears. He had made an invalid simplifying assumption which negated his assumption of constant population size, and had also incorrectly assumed that two mutations would take twice as long to reach fixation as one, while sexual recombination means that two can be selected simultaneously so that both reach fixation more quickly. The creationist claim is based on further errors and invalid assumptions.