Publications and drafts by topic: Genome
Ehud Lamm & Eva Jablonka, The Nurture of Nature: Hereditary Plasticity in Evolution. In Philosophical Psychology 21 (3):305–319, 2008 [Page]
The dichotomy between Nature and Nurture, which has been dismantled within the framework of development, remains embodied in the notions of plasticity and evolvability. We argue that plasticity and evolvability, like development and heredity, are neither dichotomous nor distinct: the very same mechanisms may be involved in both, and the research perspective chosen depends to a large extent on the type of problem being explored and the kinds of questions being asked. Epigenetic inheritance leads to transgenerationally extended plasticity, and developmentally-induced heritable epigenetic variations provide additional foci for selection that can lead to evolutionary change. Moreover, hereditary innovations may result from developmentally induced large-scale genomic repatterning events, which are akin to Goldschmidtian “systemic mutations”. The epigenetic mechanisms involved in repatterning can be activated by both environmental and genomic stress, and lead to phylogenetic as well as ontogenetic changes. Hence, the effects and the mechanisms of plasticity directly contribute to evolvability.
Ehud Lamm, The Metastable Genome: A Lamarckian Organ in a Darwinian World?. In Eva Jablonka & Snait Gissis (eds.), Transformations of Lamarckism: from subtle fluids to molecular biology, 2011 [Page|PDF ]
Ehud Lamm, The genome as a developmental organ. In Journal of Physiology 592 (11):2237-2244 (2014), 2014 [Page]
This paper applies the conceptual toolkit of Evolutionary Developmental Biology (evo‐devo) to the evolution of the genome and the role of the genome in organism development. This challenges both the Modern Evolutionary Synthesis, the dominant view in evolutionary theory for much of the 20th century, and the typically unreflective analysis of heredity by evo‐devo. First, the history of the marginalization of applying system‐thinking to the genome is described. Next, the suggested framework is presented. Finally, its application to the evolution of genome modularity, the evolution of induced mutations, the junk DNA versus ENCODE debate, the role of drift in genome evolution, and the relationship between genome dynamics and symbiosis with microorganisms are briefly discussed.
Ehud Lamm, Systems Thinking Versus Population Thinking: Genotype Integration and Chromosomal Organization 1930s–1950s. In Journal of the History of Biology, 2015 [Page]
This article describes how empirical discoveries in the 1930s–1950s regarding population variation for chromosomal inversions affected Theodosius Dobzhansky and Richard Goldschmidt. A significant fraction of the empirical work I discuss was done by Dobzhansky and his coworkers; Goldschmidt was an astute interpreter, with strong and unusual commitments. I argue that both belong to a mechanistic tradition in genetics, concerned with the effects of chromosomal organization and systems on the inheritance patterns of species. Their different trajectories illustrate how scientists’ commitments affect how they interpret new evidence and adjust to it. Dobzhansky was moved to revised views about selection, while Goldschmidt moved his attention to different genetic phenomena. However different, there are significant connections between the two that enrich our understanding of their views. I focus on two: the role of developmental considerations in Dobzhansky’s thought and the role of neutrality and drift in Goldschmidt’s evolutionary account. Dobzhansky’s struggle with chromosomal variation is not solely about competing schools of thought within the selectionist camp, as insightfully articulated by John Beatty, but also a story of competition between selectionist thinking and developmental perspectives. In contraposition, Goldschmidt emphasized the role of low penetrance mutations that spread neutrally and pointed out that drift could result from developmental canalization. This account adds to the dominant story about Goldschmidt’s resistance to the splitting of development from genetics, as told by Garland Allen and Michael Dietrich. The story I tell illustrates how developmental thinking and genetic thinking conflicted and influenced researchers with different convictions about the significance of chromosomal organization.
Ehud Lamm and Eva Jablonka, Lamarck’s Two Legacies: A 21st-century Perspective on Use-Disuse and the Inheritance of Acquired Characters. In Interdisciplina. vol 3 (5): January-April 2015, 2015 [Page|PDF ]
Lamarck has left many legacies for future generations of biologists. His best known legacy was an explicit suggestion, developed in the Philosophie zoologique (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. We put these laws in their historical context and distinguish between Lamarck’s key insights and later neo-Lamarckian interpretations of his ideas. 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.
Sophie Juliane Veigl, Oren Harman, Ehud Lamm, Friedrich Miescher’s Discovery in the Historiography of Genetics: From Contamination to Confusion, from Nuclein to DNA. In Journal of the History of Biology 53, 451–484, 2020 [Page]
In 1869, Johann Friedrich Miescher discovered a new substance in the nucleus of living cells. The substance, which he called nuclein, is now known as DNA, yet both Miescher’s name and his theoretical ideas about nuclein are all but forgotten. This paper traces the trajectory of Miescher’s reception in the historiography of genetics. To his critics, Miescher was a “contaminator,” whose preparations were impure. Modern historians portrayed him as a “confuser,” whose misunderstandings delayed the development of molecular biology. Each of these portrayals reflects the disciplinary context in which Miescher’s work was evaluated. Using archival sources to unearth Miescher’s unpublished speculations—including an analogy between the hereditary material and language, and a speculation that a series of asymmetric carbon atoms could account for hereditary variation—this paper clarifies the ways in which the past was judged through the lens of contemporary concerns. It also shows how organization, structure, function, and information were already being considered when nuclein was first discovered nearly 150 years ago.
Ehud Lamm, Oren Harman, Sophie Juliane Veigl, Before Watson and Crick in 1953 Came Friedrich Miescher in 1869. In Genetics 215(2):291-296, 2020 [Page]
In 1869, the young Swiss biochemist Friedrich Miescher discovered the molecule we now refer to as DNA, developing techniques for its extraction. In this paper we explain why his name is all but forgotten, and his role in the history of genetics is mostly overlooked. We focus on the role of national rivalries and disciplinary turf wars in shaping historical memory, and on how the story we tell shapes our understanding of the science. We highlight that Miescher could just as correctly be portrayed as the person who understood the chemical nature of chromatin (before the term existed), and the first to suggest how stereochemistry might serve as the basis for the transmission of hereditary variation.
Michael R. Dietrich, Oren Harman, Ehud Lamm, Richard Lewontin and the ‘complications of linkage’. In Studies in History and Philosophy of Science Part A 88: 237–244, 2021 [Page]
During the 1960s and 1970s population geneticists pushed beyond models of single genes to grapple with the effect on evolution of multiple genes associated by linkage. The resulting models of multiple interacting loci suggested that blocks of genes, maybe even entire chromosomes or the genome itself, should be treated as a unit. In this context, Richard Lewontin wrote his famous 1974 book The Genetic Basis of Evolutionary Change, which concludes with an argument for considering the entire genome as the unit of selection as a result of linkage. Why did Lewontin and others devote so much intellectual energy to the “complications of linkage” in the 1960s and 1970s? We argue that this attention to linkage should be understood in the context of research on chromosomal inversions and co-adapted gene complexes that occupied mid-century evolutionary genetics. For Lewontin, the complications of linkage were an extension of this chromosomal focus expressed in the new language of models for linkage disequilibrium.
Ehud Lamm and Sophie Juliane Veigl, Back to Chromatin: ENCODE and the Dynamic Epigenome. In Biological Theory, 2022 [Page]
The “Encyclopedia of DNA Elements” (ENCODE) project was launched by the US National Human Genome Research Institute in the aftermath of the Human Genome Project (HGP). It aimed to systematically map the human transcriptome, and held the promise that identifying potential regulatory regions and transcription factor binding sites would help address some of the perplexing results of the HGP. Its initial results published in 2012 produced a flurry of high-impact publications as well as criticisms. Here we put the results of ENCODE and the work on epigenomics that followed in a broad theoretical and historical context, focusing on three strands of research. The first is the history of thinking about the organization of genomes, both physical and regulatory. The second is the history of ideas about gene regulation, primarily in eukaryotes. Finally, and connecting these two issues, we suggest how to think about the role of genetic material in physiology and development.
Unpublished drafts and work in progress
Ehud Lamm, What passes for population thinking? Reflections on Peter Godfrey-Smith’s Darwinian Populations and Natural Selection.
Ehud Lamm, Genetics and Epigenetics Meet in the Genome. [Page]