Claude Bernard's non reception of Darwinism.

The aim of this paper is to explain why, while Charles Darwin was well recognized as a scientific leader of his time, Claude Bernard never really regarded Darwinism as a scientific theory. The lukewarm reception of Darwin at the Académie des Sciences of Paris and his nomination to a chair only after 8 years contrasts with his prominence, and Bernard's attitude towards Darwin's theory of species evolution belongs to this French context. Yet we argue that Bernard rejects the scientific value of Darwinian principles mainly for epistemological reasons. Like Darwin, Bernard was interested in hereditary processes, and planned to conduct experiments on these processes that could lead to species transformation. But the potential creation of new forms of life would not vindicate Darwinism since biologists can only explain the origin of morphotypes and morphological laws by the means of untestable analogies. Because it can be the object neither of experiments nor of any empirical observation, phylogeny remains out of science's scope. Around 1878 Bernard foresaw a new general physiology based on the study of protoplasm, which he saw as the agent of all basic living phenomena. We will analyze why Bernard regarded Darwinism as part of metaphysics, yet still referred to Darwinians in his latter works in 1878. Basically, the absence of a scientific reception of Darwinism in Bernard's work should not obscure its philosophical reception, which highlights the main principles of Bernard's epistemology.

Time to synchronize our clocks: Connecting developmental mechanisms and evolutionary consequences of heterochrony.

Heterochrony, defined as a change in the timing of developmental events altering the course of evolution, was first recognized by Ernst Haeckel in 1866. Haeckel's original definition was meant to explain the observed parallels between ontogeny and phylogeny, but the interpretation of his work became a source of controversy over time. Heterochrony took its modern meaning following the now classical work in the 1970-80s by Steven J. Gould, Pere Alberch, and co-workers. Predicted and described heterochronic scenarios emphasize the many ways in which developmental changes can influence evolution. However, while important examples of heterochrony detected with comparative morphological methods have multiplied, the more mechanistic understanding of this phenomenon lagged conspicuously behind. Considering the rapid progress in imaging and molecular tools available now for developmental biologists, this review aims to stress the need to take heterochrony research to the next level. It is time to synchronize the different levels of heterochrony research into a single analysis flow: from studies on organismal-level morphology to cells to molecules and genes, using complementary techniques. To illustrate how to achieve a more comprehensive understanding of phyletic morphological diversification associated with heterochrony, we discuss several recent case studies at various phylogenetic scales that combine morphological, cellular, and molecular analyses. Such a synergistic approach offers to more fully integrate phylogenetic and ontogenetic dimensions of the fascinating evolutionary phenomenon of heterochrony.

The First Brazilian Thesis of Evolution: Haeckel's Recapitulation Theory and Its Relations with the Idea of Progress.

The aim of this work is to present the thesis "On the Ontogenetic Evolution of the Human Embryo in its Relations with Phylogenesis," by Affonso Regulo de Oliveira Fausto (1866-1930), published in Brazil in 1890. To our knowledge, it was one of the first Brazilian academic works focused specifically on evolution. It was also the first doctoral thesis that addressed the topic of recapitulation in order to analyze what was then called the progressive evolution of the human species in tandem with the embryological development of the individuals that would constitute the Brazilian "type." In the present work, we analyze the author's thesis in relation to its sources, concepts, as well as the country's political context at the time of its publication. Fausto's text, in which he explicitly recognized the influence of Ernst Haeckel's (1834-1919) recapitulation theory, represents a window to understand better a concept of nation based on science and on the idea of inexorable progress that was accepted in Brazil at the end of the nineteenth century.

Ernst Haeckel, Nikolai Miklucho-Maclay and the racial controversy over the Papuans.

BACKGROUND: The "German Darwin" Ernst Haeckel (1834-1919) was a key figure during the first "Darwinian revolution", a time when the foundations of the modern evolutionary theory were laid. It was Haeckel, who crucially contributed to the visualization of the Darwinian theory by designing "genealogical-trees" illustrating the evolution of various species, including humans. Although the idea of explaining human evolution by natural selection belongs to Darwin, Haeckel was the first who attempted to create a new exact anthropology based on the Darwinian method. DISCUSSION: Trying to immediately reconstruct human evolution proceeding from the description of modern populations led Haeckel to the views which, from the contemporary perspective, are definitely racist. Haeckel created racial anthropology intending to prove human origins from a lower organism, but without the intention of establishing a discriminatory racial praxis. Although hierarchical in its outcome, the Haeckelian method did not presuppose the necessity of a racial hierarchy of currently living humans. It is crucial to grasp in what sense Haeckel's theoretical explorations in human evolution were racist, and in what sense they were not. Our argument flows as follows. One of Haeckel's pupils was the Russian ethnographer, anthropologist and zoologist Nikolai Nikolajewitsch Miklucho-Maclay (1846-1888). Maclay and Haeckel worked closely together for several years; they traveled jointly and Maclay had enough time to learn the major methodological principles of Haeckel's research. Yet in contrast to Haeckel, Maclay is regarded as one of the first scientific anti-racists, who came to anti-racist views using empirical field studies in Papua-New Guinea. CONCLUSIONS: We claim that while conducting these studies Maclay applied scientific principles to a significant extent acquired from Haeckel. The paper contributes to the view that Haeckel's theoretical racism did not follow the Darwinian method he used.

[Richard Semon (1859-1918): expeditions, engrams and epigenetics]. / Richard Semon (1859­1918): Expeditionen, Engramme und Epigenetik.

Richard Semon (1859-1918) was a student of Ernst Haeckel and began his career as a zoologist with work on sea urchins, starfish, chicken and lung fish, which he collected at the Mediterranean Sea and in Australia. After his return to Germany he was forced to leave Jena and the university due to private reasons, and settled in Munich, where Semon devoted most of his time to the more philosophical aspects of biology, developed the theory of "mneme" (1904), which he extended towards the inheritance of acquired characteristics (1912). Semon's concept of memory reached far beyond the brain and the individual person. In 1918 he took his life, despondent because of a surmised lack of scientific appreciation, the death of his beloved wife, the political turmoil at the end of WWI, and his-the memory researcher's-suspected loss of memory. Eight years later, the experimental biologist Paul Kammerer (1880-1926) from Vienna, Semon's must trusted source for the inheritance of acquired characteristics, also shot himself. Serious doubts increasingly overshadowed his work on salamanders and midwife toads. Epigenetics, the nature of memory, the fear of cognitive impairment, depression, the impact of private and political matters on scientific work, suspected scientific errors, fraud and a scientists' suicides are condensed in Semon's life and death.

Ernst Haeckel, ancient forests, and the Anthropocene.

In this Addendum to an article in  Nature commemorating the 100th anniversary of Ernst Haeckel's death (9 August 1919), we recall the largely forgotten fact that Haeckel (1868) was an early proponent of the concept of an "Anthropozoic Age", a 19th-century anticipation of the "Anthropocene". Haeckel in particular highlighted man's extensive remodeling of the planet in ancient forests. Earlier influences on Haeckel included Alexander von Humboldt (1769-1859) and dozens of similar writers in the 19th century Romantic era, including the Italian geologist and priest Antonio Stoppani (1824-1891), and the American diplomat and environmentalist George P. Marsh (1801-1882). Starting in the 1840s, Marsh described in extraordinary detail the destructive influence of mankind on natural ecosystems, again with particular emphasis on the destruction of forests. Marsh, like Haeckel after him, was a pioneer in describing the far-reaching human re-modeling of the planet that they and their colleagues presciently labeled the "Anthropozoic Age".

Plasmodial slime molds and the evolution of microbial husbandry.

Detailed analyses into the life cycle of the soil-dwelling microbe Dictyostelium discoideum led to the conclusion that this "social amoeba" practices some form of "non-monoculture farming" via the transfer of bacteria to novel environments. Herein, we show that in myxomycetes (plasmodial slime molds or myxogastrids) a similar "farming symbiosis" has evolved. Based on laboratory studies of two representative species in the genera Fuligo and Didymium, the sexual life cycle of these enigmatic microbes that feed on bacteria was reconstructed, with reference to plasmo- and karyogamy. We document that the spores carry and transfer bacteria and hence may inoculate new habitats. The significance of this finding with respect to Ernst Haeckel's work on myxomycetes and his concept of ecology are addressed.

The concept of the 'organic individual' in Haeckel's writings.

Biological individuality was a hotly debated concept in nineteenth-century German biology, both in botany and in zoology. Much discussion centered on a comparison of higher plants with colonial organisms that are subject to polymorphism and exhibit division of labor among their parts. Building on the work of Matthias Jakob Schleiden, Johannes Müller, Rudolf Leuckart, and especially the botanist Alexander Braun, Haeckel in his writings continued to refine his theory of relative individuality. Haeckel recognized three kinds of individuality: physiological, morphological, and genealogical, the latter two hierarchically structured. These distinctions allowed him to embed in his theory of relative (biological) individuality the threefold parallelism of ontogeny, phylogeny, and classification. For Haeckel, this threefold parallelism provided the strongest proof for Darwin's theory of descent with modification.

Ernst Haeckel (1834-1919): The German Darwin and his impact on modern biology.

The year 2019 marks the 100th anniversary of the death of Ernst Haeckel, a German zoologist, artist, and philosopher of science, who defended and supplemented Charles Darwin's system of theories regarding the mechanisms of biological evolution. We briefly recapitulate Haeckel's remarkable career and reproduce the Laudatio read by the President of the Linnean Society of London (1 July 1908), when Haeckel was awarded the Darwin-Wallace Medal. Finally, we summarize the importance of Haeckel's original concepts, insights, and theories with reference to our current knowledge in the areas of evolutionary biology, molecular phylogenetics, systematic zoology, and philosophical issues today.

Ernst Haeckel's "ecology" in Russia of the first half of the twentieth century.

The vast scientific heritage of Ernst Haeckel, evolutionist and thinker, comprises ecology as well. It is well known that it was he in 1866 introduced the term "ecology" for the science on interaction of the organisms and the environment. Haeckel built his system of the biological science (to be more precise, of the zoological science), including ecology, on the basis of Charles Darwin's evolutionary theory (the theory of natural selection). Traditionally, it is supposed that Haeckel's merit in world ecology is just the introduction of its name. However, there are few works devoting to development of Russian ecology. Actually, analysis of the impact of Haeckel's ecological views on Russian biologists and development of ecology in the first half of the last century demonstrates that widely used opinion should be corrected. I hypothesise that Haeckel's influence on Russian biologists was somewhat more than commonly thought. In spite of a rather long oblivion of the term "ecology" in the Russian literature followed by confusion of ecology and some other sciences (physiology, biogeography), some biologists saw in the Haeckel's understanding of ecology the base for synthesis of ecology and the evolutionary theory. There are some specific traits of Haeckel's influence on Russian biologists. At first, some of them accepted his evolutionary approach. Secondly, they highly appreciated his definition of ecology. Biologists defended such understanding of ecology even in the period of Lysenkoism pressure. At the same time, it is evident that Haeckel's influence on development of ecology was somewhat limited.