Round 6: Attempted Reconciliation Between Mendel’s and Ancestral Laws: The Birth of the (Hardy-Weinberg) Equilibrium Law (Yule 1902, Castle 1903, Pearson 1904, Hardy 1908, Weinberg 1908)

Amid the bitter biometry-saltationismbiometry-saltationism debate debate, Yule wrote a 1902 paper, which attempted to reconcile Galton’sGalton, Francis ancestral lawancestral law and Mendel’sMendel, Gregor Johann laws. In his paper, Yule also derived, for equal gamete frequencies, the so-called Hardy-Weinberg (HW) lawHW law, although he showed some misunderstanding of Mendel’sMendel, Gregor Johann law of segregationlaw of segregation. In a 1903 paper criticizing Yule’s mistake, CastleCastle, William Ernest derived the HW in its full generality. Like Yule earlier, Pearson also attempted a reconciliation in 1904 and derived the HW lawHW law for equal gamete frequencies. In response to a query from Punnett, the pure mathematician Hardy explicitly derived the HW lawHW law in 1908. Stern later indicated that the German physician Weinberg had independently derived a similar law a few months before Hardy’s derivation. The HW lawHW law was subsequently extended to two loci by Weinberg, Jennings, Robbins, and Lewontin and Kojima.