We salute Wilhelm Weinberg for suggesting in 1912 that achondroplastic dwarfs would tend to be among the last born children in a family, because there was then an increased probability that parental gamete-forming cells had accumulated the necessary pre-meiotic mutations (1). However, whether this was an 'astonishing intellectual leap' can be questioned. As far as my primitive German will allow, it seems that Weinberg did not cite Bateson. Yet, it is likely that Weinberg was familiar with the reduplication hypothesis of William Bateson and Reginald Punnett that postulated such mutations. Their hypothesis was presented in 1911 at the 4th International Congress of Genetics in Paris. The same year it was published in both English (2) and German journals (Mendel Festschrift; 3). From a parallel with plants, they suggested that the mutations might be localized to particular testicular segments, the 'jackpot' approach adopted by the Arnheim laboratory. In his 1974 Presidential Address at the 13th International Congress of Genetics, Curt Stern noted that while the reduplication hypothesis 'could not beat the competition' in explaining genetic linkage, nevertheless 'it was an ingenious suggestion' to propose that 'Mendelian segregation … occurs during a somatic cell division followed by differential multiplication of the different genotypes' (4). In our 2008 biography of Bateson we drew attention to the possibility that achrondroplastic dwarfism can be explained in such terms (5).

(1) Weinberg W (1912) Zur Vererbung des Zwergwuchses. Arch. Rassen-u Gesell Biolog 9: 710-717.
(2) Bateson W, Punnett RC (1911) On gametic series involving reduplication of certain terms. Journal of Genetics 1: 293-302.
(3) Bateson W, Punnett RC (1911) Verhandlungen Naturforsch. Verein. Brunn 49: 324-334.
(4) Stern C (1974) The domain of genetics. Genetics 78: 21-33.
(5) Cock AG, Forsdyke DR (2008) Treasure You Exceptions. The Science and Life of William Bateson. New York: Springer.