Towards analysis of the heritability of acquired characters: Transmutation and preinduction in Daphnia.

A revised translation of Beitrag zur Analyse der Vererbung erworbener Eigenschaften: Transmutation und Präinduktion bei Daphniden, by Richard Woltereck. This revision corrects many errors in the first draft. Published originally in the Verhandlungen der Deutschen zoologischen Gesellschaft in 1911.In this paper, Woltereck presents some long-term culture experiments in which he attempts to induce heritable phenotypic changes (and thus implicitly genotypic changes) through unaccustomed environmental exposure. He does not explicitly select any particular phenotype from these cultures.He finds that it is possible to induce changes in the first generation (which he calls “induction”) and the second generation (“preinduction”) after environmental stimuli are withdrawn, but no further.He infers that these changes are due to effects on developing embryos for induction, and on germ cells within developing embryos for preinduction.However, he concludes that he has not found evidence for the inheritance of acquired characters, as both preinduction and induction appear to be part of the animal’s inherited reaction norm, and their effects are transient. He suggests a more inclusive definition of the reaction norm to accommodate this.To explain how this might proceed, he draws upon the relatively new sciences of enzymology and immunology. He suggests that the idea of catalysis might be a good way of thinking about how genes can affect the reactions he is interested in, in that genes might be like enzymes (this is approximately three decades before Beadle and Tatum). Next, he suggests that we might understand the catalytic mechanism of such genes with an analogy to the inhibitory effects of antibodies. In short, he presents a model for gene-regulatory control of development (this is approximately five decades before Jacob and Monod).