The Case of Paul Kammerer: Evolution and Experimentation in the Early 20th Century

To some, a misguided Lamarckian and a fraud, to others a martyr in the fight against Darwinism, the Viennese zoologist Paul Kammerer (1880–1926) remains one of the most controversial scientists of the early 20th century. Here his work is reconsidered in light of turn-of-the-century problems in evolutionary theory and experimental methodology, as seen from Kammerer’s perspective in Vienna. Kammerer emerges not as an opponent of Darwinism, but as one would-be modernizer of the 19th-century theory, which had included a role for the inheritance of acquired characteristics. Kammerer attempted a synthesis of Darwinism with genetics and the chromosome theory, while retaining the modifying effects of the environment as the main source of favorable variation, and he developed his program of experimentation to support it. Kammerer never had a regular university position, but worked at a private experimental laboratory, with sidelines as a teacher and a popular writer and lecturer. On the lecture circuit he held forth on the significance of his science for understanding and furthering cultural evolution and he satisfied his passion for the arts and performance. In his dual career as researcher and popularizer, he did not always follow academic convention. In the contentious and rapidly changing fields of heredity and evolution, some of his stances and practices, as well as his outsider status and part-Jewish background, aroused suspicion and set the stage for the scandal that ended his career and prompted his suicide.     

The Use and Abuse of Sir Karl Popper

Karl Popper has been one of the few philosophers of sciences who has influenced scientists. I evaluate Popper's influence on our understanding of evolutionary theory from his earliest publications to the present. Popper concluded that three sorts of statements in evolutionary biology are not genuine laws of nature. I take him to be right on this score. Popper's later distinction between evolutionary theory as a metaphysical research program and as a scientific theory led more than one scientist to misunderstand his position on evolutionary theory as a scientific theory. In his later work Popper also introduced what he took to be improvements of evolutionary theory. Thus far these improvements have had almost no influence on evolutionary biology. I conclude by examining the influence of Popper on the reception of cladistic analysis.     

Weismann Rules! OK? Epigenetics and the Lamarckian temptation

August Weismann rejected the inheritance of acquired characters on the grounds that changes to the soma cannot produce the kind of changes to the germ-plasm that would result in the altered character being transmitted to subsequent generations. His intended distinction, between germ-plasm and soma, was closer to the modern distinction between genotype and phenotype than to the modern distinction between germ cells and somatic cells. Recently, systems of epigenetic inheritance have been claimed to make possible the inheritance of acquired characters. I argue that the sense in which these claims are true does not challenge fundamental tenets of neo-Darwinism. Epigenetic inheritance expands the range of options available to genes but evolutionary adaptation remains the product of natural selection of ‘random’ variation.     

Heritable alteration in DNA methylation induced by nitrogen-deficiency stress accompanies enhanced tolerance by progenies to the stress in rice (Oryza sativa L.)

Cytosine methylation is responsive to various biotic- and abiotic-stresses, which may produce heritable epialleles. Nitrogen (N)-deficiency is an abiotic stress being repeatedly experienced by plants. To address possible epigenetic consequences of N-deficiency-stress, we investigated the stability of cytosine methylation in rice (Oryza sativa L.) subsequent to a chronic (a whole-generation) N-deficiency at two levels, moderate (20 mg/L) and severe (10 mg/L), under hydroponic culture. MSAP analysis revealed that locus-specific methylation alteration occurred in leaf-tissue of the stressed plants (S₀) experiencing either level of N-deficiency, which was validated by gel-blotting. Analysis on three non-stressed self-fed progenies (S₁, S₂ and S₃) by gel-blotting indicated that ca. 50% of the altered methylation patterns in somatic cells (leaf) of the stressed S₀ plants were recaptured in S₁, which were then stably inherited to S₂ and S₃. Bisulfite sequencing of two variant MSAP loci with homology to low-copy retrotransposons on one stressed plant (S₀) and its non-stressed progenies (S₁ and S₂) showed that whereas one locus exhibited limited and non-heritable CHH methylation alteration, the other locus manifested dramatic heritable hypermethylation at nearly all cytosine sites within the assayed region. Intriguingly, when two groups of S₂ plants descended from the same N-deficiency-stressed S₀ plant were re-subjected to the stress, the group inheriting the modified methylation patterns showed enhanced tolerance to the N-deficiency-stress compared with the group bearing the original patterns. Our results thus demonstrate heritability of an acquired adaptive trait in rice, which was accompanied by epigenetic inheritance of modified cytosine methylation patterns, implicating an epigenetic basis underlying the inheritance of an acquired trait in plants.     

Freud’s Lamarckism’ and the Politics of Racial Science

This article re-contextualizes Sigmund Freud’s interest in the idea of the inheritance of acquired characteristics in terms of the socio-political connotations of Lamarckism and Darwinism in the 1930s and 1950s. Many scholars have speculated as to why Freud continued to insist on a supposedly outmoded theory of evolution in the 1930s even as he was aware that it was no longer tenable. While Freud’s initial interest in the inheritance of phylogenetic memory was not necessarily politically motivated, his refusal to abandon this theory in the 1930s must be understood in terms of wider debates, especially regarding the position of the Jewish people in Germany and Austria. Freud became uneasy about the inheritance of memory not because it was scientifically disproven, but because it had become politically charged and suspiciously regarded by the Nazis as Bolshevik and Jewish. Where Freud seemed to use the idea of inherited memory as a way of universalizing his theory beyond the individual cultural milieu of his mostly Jewish patients, such a notion of universal science itself became politically charged and identified as particularly Jewish. The vexed and speculative interpretations of Freud’s Lamarckism are situated as part of a larger post-War cultural reaction against Communism on the one hand (particularly in the 1950s when Lamarckism was associated with the failures of Lysenko), and on the other hand, against any scientific concepts of race in the wake of World War II.     

Psychoontogeny and psychophylogeny: Bernhard Rensch’s (1900–1990) selectionist turn through the prism of panpsychistic identism

Toward the end of the 1930s, Bernhard Rensch (1900–1990) turned from Lamarckism and orthogenesis to selectionism and became one of the key figures in the making of the Synthetic Theory of Evolution (STE). He contributed to the Darwinization of biological systematics, the criticism of various anti-Darwinian movements in the German lands, but more importantly founded a macroevolutionary theory based on Darwinian gradualism. In the course of time, Rensch’s version of the STE developed into an all-embracing metaphysical conception based on a kind of Spinozism. Here we approach Rensch’s “selectionist turn” by outlining its context, and by analyzing his theoretical transformation. We try to reconstruct the immanent logic of Rensch’s evolution from a “Lamarckian Synthesis” to a “Darwinian Synthesis”. We will pay close attention to his pre-Darwinian works, because this period has not been treated in detail in English before. We demonstrate an astonishing continuity in topics, methodology, and empirical generalizations despite the shift in Rensch’s views on evolutionary mechanisms. We argue that the continuity in Rensch’s theoretical system can be explained, at last in part, by the guiding role of general methodological principles which underlie the entire system, explicitly or implicitly. Specifically, we argue that Rensch’s philosophy became an asylum for the concept of orthogenesis which Rensch banned from evolutionary theory. Unable to explain the directionality of evolution in terms of empirically based science, he “pre-programmed” the occurrence of human-level intelligence by a sophisticated philosophy combined with a supposedly naturalistic evolutionary biology.

Is cultural evolution Lamarckian?

The article addresses the question whether culture evolves in a Lamarckian manner. I highlight three central aspects of a Lamarckian concept of evolution: the inheritance of acquired characteristics, the transformational pattern of evolution, and the concept of directed changes. A clear exposition of these aspects shows that a system can be a Darwinian variational system instead of a Lamarckian transformational one, even if it is based on inheritance of acquired characteristics and/or on Lamarckian directed changes. On this basis, I apply the three aspects to culture. Taking for granted that culture is a variational system, based on selection processes, I discuss in detail the senses in which cultural inheritance can be said to be Lamarckian and in which sense problem solving, a major factor in cultural change, leads to directed variation.     

Gene duplication and other evolutionary strategies: from the RNA world to the future

Beginning with a hypothetical RNA world, it is apparent that many evolutionary transitions led to the complexity of extant species. The duplication of genetic material is rooted in the RNA world. One of two major routes of gene amplification, retroposition, originated from mechanisms that facilitated the transition to DNA as hereditary material. Even in modern genomes the process of retroposition leads to genetic novelties including the duplication of protein and RNA coding genes, as well as regulatory elements and their juxtapositon. We examine whether and to what extent known evolutionary principles can be applied to an RNA-based world. We conclude that the major basic Neo-Darwinian principles that include amplification, variation and selection already governed evolution in the RNA and RNP worlds. In this hypothetical RNA world there were few restrictions on the exchange of genetic material and principles that acted as borders at later stages, such as Weismann's Barrier, the Central Dogma of Molecular Biology, or the Darwinian Threshold were absent or rudimentary. RNA was more than a gene: it had a dual role harboring, genotypic and phenotypic capabilities, often in the same molecule. Nuons, any discrete nucleic acid sequences, were selected on an individual basis as well as in groups. The performance and success of an individual nuon was markedly dependent on the type of other nuons in a given cell. In the RNA world the transition may already have begun towards the linkage of nuons to yield a composite linear RNA genome, an arrangement necessitating the origin of RNA processing. A concatenated genome may have curbed unlimited exchange of genetic material; concomitantly, selfish nuons were more difficult to purge. A linked genome may also have constituted the beginning of the phenotype/genotype separation. This division of tasks was expanded when templated protein biosynthesis led to the RNP world, and more so when DNA took over as genetic material. The aforementioned barriers and thresholds increased and the significance and extent of horizontal gene transfer fluctuated over major evolutionary transitions. At the dawn of the most recent transformation, a fast evolutionary transition that we will be witnessing in our life times, a form of Lamarckism is raising its head.     

拉马克的归来—对达尔文主义的再审视

适应性突变（adaptive mutation）和表观遗传学（epigenetics）的新进展为拉马克主张的＂获得性遗传＂提供了越来越多的证据,暗示它在生物进化中所起的作用可能远比我们之前想象的要大的多。这虽然与新达尔文主义相左,但却在一定程度上符合经典达尔文主义：作为＂自然选择＂的重要补充,＂获得性遗传＂至少应视作一个辅助的机制而纳入＂达尔文框架＂中。这种建立在多元论基础上的进化观正是达尔文留给后人最重要的遗产。     

Nature and nurture: Lamarck's legacy

This year (2014) marks the 270th anniversary of Jean‐Baptiste de Lamarck's birth, which presents a good occasion to reflect on the wide‐reaching, although largely ignored, legacy of the French naturalist and its modern‐day renaissance. A discussion is provided of the broad and controversial influence of Lamarckian thought on science, politics and art, with a focus on Lamarck's curious recent comeback to the public and academic eyes in relation to the burgeoning discipline of epigenetics. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 114 , 242–247.