Plant "intelligence" and the misuse of historical sources as evidence.

Proponents of the concepts of plant intelligence and plant neurobiology often use historical sources as "evidence" and argue that eminent past scientists have supported ideas of plant intelligence, memory, learning, decision-making, agency, and consciousness. Historical sources include writings by Charles Darwin, Julius von Sachs, F. W. Went, K. V. Thimann, Barbara McClintock, and J. B. Lamarck. Advocates of plant neurobiology also argue that the ideas of J. C. Bose, an Indian scientist who is considered an important forerunner of plant neurobiology, were suppressed chiefly because of racism. Plant neurobiology has been criticized on scientific grounds, but there has not been close scrutiny of the use of historical sources as a form of evidence. We provide the first in-depth analysis of how historical sources have been used and misused, and conclude that there is a consistent pattern of distortion of these sources. Distortions include the use of erroneous quotations, alteration of quotations, selective quotations without context, and misinterpretation and exaggeration of historical statements. In the case of Bose, we show that there were legitimate scientific reasons for questioning his interpretations of botanical experiments and argue that this context cannot be ignored in evaluating contemporary responses to Bose. Overall, the common practice by proponents of plant intelligence and plant consciousness of uncritically citing the words of eminent scientists of the past, taken out of their historical context to bolster their arguments, should not be confused with scientific evidence supporting these concepts, even when the quotations, themselves, are accurate.

[What Charles Darwin owed to Joseph Banks]. / Ce que Charles Darwin doit à Joseph Banks.

History has remembered Joseph Banks as the explorer-botanist of the first voyage of James Cook. Yet, shortly after his return, he got elected president of the Royal Society and, for over 40 years, he then played in Great Britain an eminent role in reorganizing natural sciences and advocating an "economic botany". He actively intervened in acclimatization and varietal selection of plants and animals in Great Britain as in the future English colonies. Thus he built an intellectual environment which will promote the emergence of Charles Darwin's thoughts.

L'histoire retient Joseph Banks comme l'explorateur-botaniste du premier voyage de James Cook. Pourtant, peu de temps après son retour, il se fait élire président de la Royal Society et joue alors, pendant plus de 40 ans, un rôle éminent en Grande-Bretagne en réorganisant les sciences naturalistes et en prônant une « botanique économique ¼ . Il intervient activement pour l'acclimatation et la sélection variétale de plantes et d'animaux en Grande-Bretagne comme dans les futures colonies anglaises. Ainsi il construit un environnement intellectuel qui favorisera l'émergence de la pensée de Charles Darwin.

Darwin and the White Shipwrecked Sailor: Beyond Blending Inheritance and the Jenkin Myth.

This paper revisits Fleeming Jenkin's anonymous review of Charles Darwin's Origin of Species, published in the North British Review in June 1867. This review is usually revered for its impact on Darwin's theory of descent with modification. Its classical interpretation states that Jenkin, a Professor of Engineering at the University of Edinburgh, made a compelling case against natural selection based on the fact of "blending inheritance" and the "swamping" of advantageous variations. Those themes, however, are strikingly absent from Jenkin's text. They were later read into Jenkin's text by scholars trying to explain how Darwinian selection was reconciled with Mendelian genes and the birth of the Modern Synthesis. While many scholars have tried to measure Jenkin's effect on Darwin, the value of the 1867 review remains unclear. This paper re-examines its content and concludes that Jenkin's "able review" was in fact written by an engineer whose competencies in biology were very low. Focusing on the figure of the shipwrecked white sailor isolated on an island inhabited by Black people, this paper also underlines the racial assumptions behind Jenkin's review. "Blending inheritance" is thus a theme linked to theoretical reworkings on the question of race and skin colors, taking its root in Galton's typology of heredity. Darwin was probably mostly unimpressed by Jenkin's review. The problems raised by the review were not so much "blending inheritance" and "swamping" but a conundrum of problems related to the effects of intercrossing on variation and reversion.

Invasion on So Grand a Scale: Darwin, Lyell, and Invasive Species.

The importance of naturalization-the establishment of species introduced into foreign places-to the early development of Darwin's theory of evolution deserves historical attention. Introduced and invasive European species presented Darwin with interpretive challenges during his service as naturalist on the HMS Beagle. Species naturalization and invasive species strained the geologist Charles Lyell's creationist view of the organic world, a view which Darwin adopted during the voyage of the Beagle but came to question afterward. I suggest that these phenomena primed Darwin to question the "stability of species." I then examine the role of introduced and invasive species in Darwin's early theorizing and negotiation with Lyell's ideas, recorded in his post-voyage "transmutation notebooks." Therein, the subject was an inflection point in his contention with Lyell's views and moreover, his theorizing on invasive species occasioned some of his earliest inklings of natural selection. Finally, I examine how naturalization was crucial to Lyell's own eventual conversion to evolutionism. I conclude with brief reflections on the implications of this narrative for our understanding of Darwin's reasoning, his intellectual relationship to Lyell, and the historical context that shaped his theory.

It Ain't Necessarily So: Ludwig Boltzmann's Darwinian Notion of Entropy.

Ludwig Boltzmann's move in his seminal paper of 1877, introducing a statistical understanding of entropy, was a watershed moment in the history of physics. The work not only introduced quantization and provided a new understanding of entropy, it challenged the understanding of what a law of nature could be. Traditionally, nomological necessity, that is, specifying the way in which a system must develop, was considered an essential element of proposed physical laws. Yet, here was a new understanding of the Second Law of Thermodynamics that no longer possessed this property. While it was a new direction in physics, in other important scientific discourses of that time-specifically Huttonian geology and Darwinian evolution, similar approaches were taken in which a system's development followed principles, but did so in a way that both provided a direction of time and allowed for non-deterministic, though rule-based, time evolution. Boltzmann referred to both of these theories, especially the work of Darwin, frequently. The possibility that Darwin influenced Boltzmann's thought in physics can be seen as being supported by Boltzmann's later writings.

Speciation by physiological selection of environmentally acquired traits.

A chance mutation affecting a single or extremely few individuals in a continuous population will be quickly diluted through interbreeding. Charles Darwin fully appreciated this difficulty with relying on natural selection alone, and suggested an enabling role for geographical isolation in the origin of species. However, Darwin also believed in evolution by the inheritance of acquired traits and in populations of interbreeding animals, both of which would need a different isolating mechanism to overcome dilution and play a role in animal evolution. Historically disputed, the inheritance of acquired characters is now increasingly accepted as a phenomenon, and Charles Darwin himself is acknowledged as closely pre-empting the type of physiology necessary to mediate it in his hypothesis of 'pangenesis'. In this article, we question how the inheritance of acquired traits might overcome the problem of dilution by interbreeding and contribute to evolution. Specifically, we describe how Darwin's young protégé, George Romanes, developed ideas he discussed with Darwin and extended pangenesis to include a conceivable solution published after Darwin's death: physiological selection of fertility. In light of the 'rediscovery' of pangenesis, here we recount physiological selection as a testable hypothesis to explain how environmentally acquired characteristics could become coupled to the generation of species.

A "Mean Quarrelsome Spirit:" Controversy in British Systematics, 1822-1836.

British systematics was distinctly marked by a raft of vituperative controversies around the turn of the 1830s. After the local collapse of broad consensus in the Linnaean system by 1820, the emergence of new schemes of classification-most notably, the "quinarian" system of William Sharp Macleay-brought with it an unprecedented register of public debate among zoologists in Britain, one which a young Charles Darwin would bitterly describe to his friend John Stevens Henslow in October 1836 as possessing a "mean quarrelsome spirit," conducted in "a manner anything but like that of gentlemen." This article aims to provide a social and conceptual account of the remarkable tenor of zoological discourse in Britain in the late 1820s and early 1830s, with joint attention to the philosophical and interpersonal commitments at play. In doing so, it analyzes the three of the period's most striking public controversies, each of which counted key advocates of the quinarian system as central participants.

Bubbling beyond the barrier: exosomal RNA as a vehicle for soma-germline communication.

'Weismann's barrier' has restricted theories of heredity to the transmission of genomic variation for the better part of a century. However, the discovery and elucidation of epigenetic mechanisms of gene regulation such as DNA methylation and histone modifications has renewed interest in studies on the inheritance of acquired traits and given them mechanistic plausibility. Although it is now clear that these mechanisms allow many environmentally acquired traits to be transmitted to the offspring, how phenotypic information is communicated from the body to its gametes has remained a mystery. Here, we discuss recent evidence that such communication is mediated by somatic RNAs that travel inside extracellular vesicles to the gametes where they reprogram the offspring epigenome and phenotype. How gametes learn about bodily changes has implications not only for the clinic, but also for evolutionary theory by bringing together intra- and intergenerational mechanisms of phenotypic plasticity and adaptation.

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.

Darwin's dark matter: utter extinction.

Species that died without leaving descendants Darwin called 'utterly extinct'. They far outnumber the ancestors of all living things, so they resemble the dark matter of modern cosmology, which far outweighs visible matter. He realized in 1837 that their absence is what creates the groups in a natural classification. In his Notebook B he combined the idea that species multiply with the idea that ancestors' relatives must mostly be extinct. The fossil Megatherium was utterly extinct. The iconic branching 'I think' diagram shows extinction causing the origin of genera by eliminating intermediate species. Darwin's concept of taxonomic ranks, starting with the genus, was informed by his interaction with taxonomists. Based on his familiarity with demography, Darwin reasoned that the survival of transitional forms was unlikely, which helped him decide to focus at the species level. When drafting his theory in the 1840s, he left out these speculative ideas, but they emerged again in the 1850s when he realized his theory needed a cause for branches to diverge. His ecological answer worked at the species level, but his Principle of Divergence was unconvincing at higher taxonomic levels. In the Origin, Darwin repeatedly insisted on the importance of utter extinction.

Breeding origins of a uniquely regular migrant songbird in the Galápagos Islands.

Little is known about the causes and consequences of alternative pathways flown by long-distance migratory birds. Bobolinks (Dolichonyx oryzivorus) breed in grasslands across northern North America and migrate from their breeding grounds toward the eastern Atlantic Coast and then proceed through the Caribbean to South America. However, a small but regular number of Bobolinks have been recorded on the Galapagos Islands. We collected genetic samples from nine Galapagos Bobolinks and performed double-digest restriction site-associated sequencing. We compared them with samples from seven locations across their breeding distribution to determine their population of origin. Galapagos Bobolinks shared the genetic structure of a cluster in the eastern portion of the breeding range that includes New Brunswick and Ontario, Canada, and Vermont, United States. Genetic assignment tests largely corroborated this finding, although slightly different results were obtained for the two methods. All individuals were assigned to the Ontario breeding population using AssignPop, while Rubias assigned six of the migrants to Ontario and three to a Midwest breeding population. Low average relatedness among Galapagos individuals indicates that they are not more related to one another than to individuals within a breeding population and are therefore likely not from a single, small isolated population. Our results do not support the probability hypothesis-that Galapagos Bobolinks originated from the region that includes the greatest proportion of their breeding range (Great Plains)-or the vagrant hypothesis-that migrants are displaced onto Galapagos due to weather events. Instead, our findings support the proximity hypothesis, where migrants originate from the geographically closest-breeding populations.

Diagnoses for Charles Darwin's Illness: A Wealth of Inaccurate Differential Diagnoses.

Charles Darwin suffered from a relapsing, debilitating illness for much of his adult life with numerous, differing symptoms. His occasional problems as a student, his seasickness throughout the voyage of the HMS Beagle, and his brief illnesses when ashore in South America and Australia were all early expressions of this illness. Diagnoses for Darwin's illness are as numerous as his symptoms and are equally variable. Many diagnoses reflect the medical fashion of their time; psychological and psychogenic diagnoses once flourished. These diagnoses have recently been comprehensively reviewed in an uncritical and unbiased account. Rather than a repeat review of diagnoses this paper aims to critique and make a critical appraisal of the diagnoses given. As stated, they are not all right. Some are not wrong but are simply incomplete. Pathological mitochondrial DNA (mtDNA) mutations are the cause of a variety of childhood diseases and more recently have been recognized as the cause of some adult-onset conditions with a plethora of presenting symptoms. The diagnosis favored here is that Darwin suffered from such a disorder due in his case to a maternally inherited pathological mtDNA mutation. This proposal should be seen in the context of self-certainty and subject to similar critical appraisal. Diagnosing Darwin may have a unique, correct solution, a solution that would benefit those who suffer from a similar disorder today and who, like Darwin, are misdiagnosed, misunderstood, and inappropriately treated.

Alexander Dalrymple, the Utility of Coral Reefs, and Charles Darwin's Structure and Distribution of Coral Reefs.

This paper aims to establish the connection between the theoretical and practical aims of the Office of the Hydrographer of the British Admiralty and Charles Darwin's (1809-1882) work on coral reefs from 1835 to 1842. I also emphasize the consistent zoological as well as geological reasoning contained in these texts. The Office's influences have been previously overlooked, despite the Admiralty's interest in using coral reefs as natural instruments. I elaborate on this by introducing the work of Alexander Dalrymple (1737-1808), the first hydrographer of the Admiralty and a figure who has flown under the radar of the history of coral reef theories. I show that Dalrymple introduced a unified account of coral reefs in which multiple features of the coral reefs, such as their shape, slope of the sides, ridges, channels, and elevation relative to the water, were all explained by the action of the winds and waves-and proposed that one could use these features to predict seafaring conditions around the islands. Then, I show that Darwin's "Coral Islands" (1835) and his Coral Reefs monograph (1842) spoke to these hydrographical issues and did so, at times, by way of zoological reasoning. It was, for instance, the coral behavior and the related notion of a zoological or botanical station that ultimately proved the biggest blow to the Admiralty's aim to use the coral reefs as instruments because it eroded many uniform predictions regarding the past or future of a coral reef. Connecting these themes leads us to a surprising conclusion: that Darwin's theory of coral reefs, long a model instance of Darwin making uniform predictable inferences, was, in actuality, also his first formal encounter with something at times the entire opposite.

Modern physiology vindicates Darwin's dream.

NEW FINDINGS: What is the topic of this review? Revisiting the 2013 article 'Physiology is rocking the foundations of evolutionary biology'. What advances does it highlight? The discovery that the genome is not isolated from the soma and the environment, and that there is no barrier preventing somatic characteristics being transmitted to the germline, means that Darwin's pangenetic ideas become relevant again. ABSTRACT: Charles Darwin spent the last decade of his life collaborating with physiologists in search of the biological processes of evolution. He viewed physiology as the way forward in answering fundamental questions about inheritance, acquired characteristics, and the mechanisms by which organisms could achieve their ends and survival. He collaborated with 19th century physiologists, notably John Burdon-Sanderson and George Romanes, in his search for the mechanisms of transgenerational inheritance. The discovery that the genome is not isolated from the soma and the environment, and that there is no barrier preventing somatic characteristics being transmitted to the germline, means that Darwin's pangenetic ideas become relevant again. It is time for 21st century physiology to come to the rescue of evolutionary biology. This article outlines research lines by which this could be achieved.

Floral evolution and pollinator diversification in Hedychium: Revisiting Darwin's predictions using an integrative taxonomic approach.

PREMISE: Hedychium J. Koenig (Zingiberaceae) is endemic to the Indo-Malayan Realm and is known for its colorful and fragrant flowers. Historically, two different pollination syndromes characterize Hedychium: diurnal or bird pollination, and nocturnal or moth pollination. In this study, we aim to understand the evolution of nocturnal and diurnal flowers, and to test its putative association with lineage diversification in Hedychium. METHODS: A molecular tree of Hedychium was used as a scaffold upon which we estimated ancestral character states, phylogenetic signals, and correlations for certain categorical and continuous floral traits. Furthermore, we used phylomorphospace and trait-dependent diversification rate estimation analyses to understand phenotypic evolution and associated lineage diversification in Hedychium. RESULTS: Although floral color and size lacked any association with specific pollinators, white or pale flowers were most common in the early branching clades when compared to bright-colored flowers, which were more widely represented in the most-derived clade IV. Five categorical and two continuous characters were identified to have informative evolutionary patterns, which also emphasized that ecology may have played a critical role in the diversification of Hedychium. CONCLUSIONS: From our phylogenetic analyses and ecological observations, we conclude that specializations in pollinator interactions are rare in the hyperdiverse clade IV, thus challenging the role of both moth-specialization and bird-specialization as central factors in the diversification of Hedychium. However, our results also suggest that clade III (predominantly island clade) may show specializations, and future studies should investigate ecological and pollinator interactions, along with inclusion of new traits such as floral fragrance and anthesis time.

Charles Bell's (1774-1842) contribution to our understanding of facial expression.

The human face reflects a person's character and emotions, both in health and disease. Charles Bell, published in 1806 Essays on the Anatomy of Expression in Painting in which he stressed the importance of understanding anatomy when studying art. He concluded that emotions were revealed in facial expression and that these expressions were only to be found in humans, not in lower animals. Charles Darwin in 1872 published The Expression of the Emotions in Man and Animals, where he acknowledged Bell's contribution to facial expression especially the role of the nervous system, but questioned Bell's conclusion, that animals were incapable of showing emotions through facial expression. Darwin reasoned that human facial expressions reflected emotions, some from our primeval state, some from habit but most were universal and controlled by an involuntary nervous system, described by Bell, and now known as the parasympathetic system. This paper explores Bell's contribution to the understanding of facial expression. We conclude that his understanding of neuroanatomy along with his artistic ability enhanced our comprehension of human facial expressions, although his theological interpretation of the reason for facial expressions and emotions needs to be seen more in the context of nineteenth century Natural Theology.

Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-Like Episodes (MELAS) in the 18th Century: Mitochondrial Disorders Are Not of Recent Origin.

Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome was one of the first mitochondrial disorders to be identified and characterized, being described as early as 1984. The clinical manifestations of MELAS vary but stroke-like episodes are a defining feature. Mutations in at least 17 mitochondrial DNA (mtDNA) located genes have been shown to be associated with this disorder. Mary Ann, the youngest child of Josiah and Sarah Wedgwood, was born in August 1778 when Sarah was aged 44 years. Mary Ann was of short stature and was physically and mentally retarded. She suffered from partial and generalized seizures and episodes of cortical blindness. She died at the age of eight years. Descriptions of her illness remain and she is depicted with disabilities as can be seen in a family portrait. Her illness is consistent with MELAS. The illnesses of her elder siblings and of their mother are in keeping with a maternally inherited pathological mtDNA mutation, supporting this diagnosis. Her illness is the key to the remarkable illnesses that affected the Wedgwood family. Through her eldest sibling, Susannah, married to Robert Darwin, the disorder was passed to the next generation, a generation that included Charles Darwin and his elder brother, Erasmus.

Whatever happened to reversion?

The idea of 'reversion' or 'atavism' has a peculiar history. For many authors in the late-nineteenth and early-twentieth centuries - including Darwin, Galton, Pearson, Weismann, and Spencer, among others - reversion was one of the central phenomena which a theory of heredity ought to explain. By only a few decades later, however, Fisher and others could look back upon reversion as a historical curiosity, a non-problem, or even an impediment to clear theorizing. I explore various reasons that reversion might have appeared to be a central problem for this first group of figures, focusing on their commitment to a variety of conceptual features of evolutionary theory; discuss why reversion might have then ceased to be an interesting phenomenon; and, finally, close with some more general thoughts about the death of scientific problems.

Evolution and ethics viewed from within two metaphors: machine and organism.

How is moral thinking, ethics, related to evolutionary theorizing? There are two approaches, epitomized by Charles Darwin who works under the metaphor of the world as a machine, and by Herbert Spencer who works under the metaphor of the world as an organism. Although the author prefers the first approach, the aim of this paper is to give a disinterested account of both approaches.

Charles Darwin's Mitochondrial Disorder: Possible Neuroendocrine Involvement.

Charles Darwin, the famous naturalist, suffered relapsing, debilitating illness for most of his adult life with a plethora of symptoms. The diagnosis favoured here for this illness is that of an adult-onset mitochondrial disorder due to a maternally inherited, pathological mitochondrial DNA mutation clinically manifesting as MELAS (mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes) syndrome. This diagnosis accounts for Darwin's primary symptoms; in addition, it accounts for the various unusual illnesses that afflicted his siblings and maternal (Wedgwood) ancestors. Symptoms of Darwin's illness may be related to dysfunction of cells with high energy requirements; this includes cells constituting the cardiac conduction system, cerebral endothelial cells, neurons, neuroepithelial cells of the vestibular apparatus, and, as proposed here, central and peripheral neuroendocrine cells. Although Darwin's episodes of sudden facial flushing, his nocturnal panic attacks, and his severe gastrointestinal symptoms are not readily explained, these symptoms may relate to neuroendocrine dysfunction, either an uncontrolled release of stimulatory hormone or impaired inhibitory control. It is also conceivable that the autonomic system had been involved. A study of Darwin's illness may benefit those who suffer from similar symptoms today.