Abstracts (first author)
(Non)-genetic inheritance: a historical overview
Current debates on the biological relevance and theoretical impacts of non-genetic inheritance in evolution seem to have much in common with archaistic debates between Neo-Lamarckians and Neo-Darwinians on the existence of inheritance of acquired characteristics. In this presentation, we will adopt a historical point of view to put the current debates into perspective. In the first part, we will first recall how the publication of The Origin made the researches about inheritance a central theme of theoretical biology, and how these researches themselves put Darwinism at risk at the turn of the XIXth-XXth centuries. We will recall how Neo-Darwinism and Neo-Lamarckism emerged during the debates on the role of acquired characteristics in heredity. We will show how, as soon as the end of the XIXth century, the inheritance of acquired characteristic has been a heterogeneous concept – heterogeneous enough to seem, in some instances, compatible with Neo-Darwinism. In the second part, we will show how, in the first part of the XXth century, researches on genetic inheritance impacted the debates about the inheritance of acquired characteristics, making them slip towards debates on the "genetic" inheritance of acquired characteristics. We will show how, in parallel, researches on non-genetic inheritance got marginalized, without disappearing totally, before blossoming again at the end of the XXth century. In conclusion, we will draw on our historical account to clarify the conceptual differences between directed mutation, the inheritance of acquired characteristics, and non-genetic inheritance. This will lead us to consider in which respect an Extended Evolutionary Theory could depart from the conceptual matrix of the Modern Synthesis.