BEAR I Genetics Panel: An unexpected and troubling historical twist: The untold story of Hermann Muller's significant scientific confusion.

Hermann J. Muller, Nobel Prize recipient for producing gene mutations, was the de facto leader of the radiation genetics community from the mid-1920s until he died in 1967. Muller had a major impact on US hereditary/cancer risk assessment policies/practices, and the course of the secondary school biological sciences curriculum development in the US and worldwide. Despite these accomplishments, Muller was at the center of provocative controversies. Within this context, this paper reports the discovery of a letter (April 4, 1956) from Muller to Warren Weaver, Chair of the BEAR I Genetics Panel, about a major controversy in which the radiation-induced hereditary damage estimates of Panelist Milisav Demerec were strikingly lower than those of others, especially Muller's. In this recently discovered letter, Muller attempted to reconcile these differences and unexpectedly claimed that Demerec's estimates were correct. However, Muller appears to have inexplicably confused the evaluation by switching his focus away from Demerec's data on radiation-induced mutation rates in bacteria to his old unresolved dispute with Demerec regarding fruit flies. He even suggested that Demerec was correct in that Muller's groundbreaking mutational research had induced mostly major chromosomal aberrations rather than gene mutations. Muller curiously suggested that he had thereby resolved the conflict amongst Demerec, himself, and other BEAR I Genetics Panel members. Yet, as noted, Demerec's data for the BEAR I Genetics Panel mutation risk estimates were based on his (i.e., Demerec's) more current research on bacteria, with Muller completely missing the entire point of the Panel's scientific conflict with the Demerec data. Thus, Muller never addressed the real issue. This transitory detachment from factual reality by Muller is obvious and acute. Finally, if Weaver had shared this letter from Muller with the BEAR I Genetics Panel, it seems possible that many members might have been so troubled by Muller's apparent detachment from reality (on such a consequential disagreement) that they would have questioned why they had allowed Muller to exert so much influence on their report.