Nicoglou Antonine, Merlin Francesca
CRPMS & IJM (University of Paris 7), Associate at IHPST, Paris, France.
IHPST (CNRS, University of Paris 1, ENS), 13 rue du Four, 75006 Paris, France.
Stud Hist Philos Biol Biomed Sci. 2017 Dec;66:73-82. doi: 10.1016/j.shpsc.2017.10.002. Epub 2017 Oct 13.
The concept of epigenetics has evolved since Waddington defined it from the late 1930s as the study of the causal mechanisms at work in development. It has become a multi-faceted notion with different meanings, depending on the disciplinary context it is used. In this article, we first analyse the transformations of the concept of epigenetics, from Waddington to contemporary accounts, in order to identify its different meanings and traditions, and to come up with a typology of epigenetics throughout its history. Second, we show on this basis that epigenetics has progressively turned its main focus from biological problems regarding development, toward issues concerning evolution. Yet, both these different epistemological aspects of epigenetics still coexist. Third, we claim that the classical opposition between epigenesis and preformationism as ways of thinking about the developmental process is part of the history of epigenetics and has contributed to its current various meanings. With these objectives in mind, we first show how Waddington introduced the term "epigenetics" in a biological context in order to solve a developmental problem, and we then build on this by presenting Nanney's, Riggs' and Holliday's definitions, which form the basis for the current conception of "molecular epigenetics". Then, we show that the evo-devo research field is where some particular uses of epigenetics have started shifting from developmental issues to evolutionary problems. We also show that epigenetics has progressively focused on the issue of epigenetic inheritance within the Extended Evolutionary Synthesis' framework. Finally, we conclude by presenting a typology of the different conceptions of epigenetics throughout time, and analyse the connections between them. We argue that, since Waddington, epigenetics, as an integrative research area, has been used to bridge the gap between different biological fields.
自20世纪30年代末沃丁顿将表观遗传学定义为对发育过程中起作用的因果机制的研究以来，这一概念不断演变。它已成为一个具有多方面含义的概念，具体含义取决于其使用的学科背景。在本文中，我们首先分析表观遗传学概念从沃丁顿时代到当代的转变，以确定其不同含义和传统，并梳理出其历史上的表观遗传学类型。其次，我们在此基础上表明，表观遗传学已逐渐将其主要关注点从与发育相关的生物学问题转向与进化相关的问题。然而，表观遗传学的这两个不同的认识论方面仍然并存。第三，我们认为，后生说与预成论作为思考发育过程的方式之间的经典对立是表观遗传学历史的一部分，并促成了其目前的各种含义。出于这些目的，我们首先展示沃丁顿如何在生物学背景下引入“表观遗传学”一词以解决一个发育问题，然后在此基础上介绍南尼、里格斯和霍利迪的定义，这些定义构成了当前“分子表观遗传学”概念的基础。然后，我们表明，进化发育生物学研究领域是表观遗传学的一些特定用途开始从发育问题转向进化问题的地方。我们还表明，表观遗传学已逐渐在扩展进化综合理论的框架内关注表观遗传继承问题。最后，我们通过呈现不同时期表观遗传学不同概念的类型学并分析它们之间的联系来得出结论。我们认为，自沃丁顿以来，表观遗传学作为一个综合研究领域，一直被用于弥合不同生物学领域之间的差距。
