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generation (which he calls “induction”) and the second generation (“preinduction”) after environmental stimuli are withdrawn, but no further.He infers that these changes are due to effects on developing embryos for induction, and on germ cells within developing embryos for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).

Lamarckian mechanisms as developmental bias and their Darwinian base – descriptive versus explanatory biology (full version)

The article points out the main obstacles in the discussion of Lamarckian mechanisms, resulting from overly persisted beliefs, habits and understatement. The aim of the article is not to show new biological observation, but to indicate the need to change methodology. ‘Lamarckian mechanisms’ are those that create ‘non-random’ changes (in the aspect of adaptation), and even ‘resulting from instruction’, and these changes become evolutionary. It is part of ‘developmental biases’. To avoid widespread prejudices a permanent stress is needed that such ‘Lamarckian mechanisms’ are an effect of Darwinian mechanisms but this stress is not enough visible. The term ‘Lamarckism’ has two meanings unreasonably connected. The correct meaning is, that adaptive evolutionary changes can be induced by environment and next they are inherited, but typically it is understood as irrational believing that evolutionary changes are adaptive without necessity of help of Darwinian mechanisms. In this case the terms ‘Lamarckian mechanisms’ and ‘Lamarckism’ are not coherent which leads to misunderstanding. Such irrational Lamarckism has small base in Lamarck’s view, it arisen from too shallow interpretation of Lamarck. In the theme ‘inheritance of acquired characters’ a few steps to evolutionary change is indicated, which typically are omitted in the description. Old such descriptions need rebuilding in a new coherent system of notions but to create such system a theory is necessary. The Lamarckian dimension of evolution protrudes beyond the basics of Modern Synthesis however necessity to change the name of the synthesis to Extended Evolutionary Synthesis is discretionary decision. It would be obligatory, when the Modern Synthesis will be treated as typical theory derived from specified assumptions when its assumptions are extended. The article points to the growing need to pay more attention to the precision of definition, specification of assumptions and abstract inference, as deficiencies in these areas are the main cause of misunderstanding and a brake on progress. Unfortunately, they are not appreciated in biology, and even ‘speculations’ are considered undesirable.

Lamarck’s Two Legacies: A 21st-Century Perspective on Use-Disuse and the Inheritance of Acquired Characters

<p class="p1"><span class="s1"><strong>Abstract </strong></span>| Lamarck has left many legacies for future generations of biologists<span class="s2"><strong>. </strong></span>His best known legacy was an explicit suggestion, developed in the <em>Philosophie zoologique </em>(PZ), that the effects of use and disuse (acquired characters) can be inherited and can drive species transformation.This suggestion was formulated as two laws, which we refer to as the law of biological plasticity and the law of phenotypic continuity<span class="s2"><strong>. </strong></span>We put these laws in their historical context and distinguish between Lamarck’s key insights and later neo-Lamarckian interpretations of his ideas<span class="s2"><strong>.</strong></span>We argue that Lamarck’s emphasis on the role played by the organization of living beings and his physiological model of reproduction are directly relevant to 21st-century concerns, and illustrate this by discussing intergenerational genomic continuity and cultural evolution.</p>