The Study of Geographical Distribution in the Analysis of Domestication as an Evolutionary Process: Tensions in Alphonse de Candolle's Approach.

Interest in the study of domesticated plants increased near the end of the 18th century, mainly because of their economic potential. In the 19th century, there was a new focus on the historical understanding of species, their origin, changes in their distribution, and their evolutionary history. Charles Darwin developed an extended interpretation of species domestication, considering variations, reproduction, inheritance, and modification as standard processes between wild and domesticated organisms. In this context, one relatively neglected aspect was the geographical distribution of domesticated species. Alphonse de Candolle addressed and developed in detail the question of the geographical origin of cultivated plants. Since 1836 Alphonse de Candolle had been studying the topic and obtained evidence that contributed to understanding aspects such as the center of origin, dispersion, competition, selection, and time of domestication. Although Darwin himself admitted that Géographie botanique raisonnée (de Candolle, Alphonse,de. Géographie botanique raisonnée; ou, exposition des faits principaux et des lois concernant la distribution géographique des plantes de l'epoque actuelle, 2ème tome. Paris: Masson.) was of great help to him in the development of his evolutionary theory, the importance of de Candolle's contribution is seldom recognized. Our purpose is to detail the dialogue between Alphonse de Candolle and Darwin on the geography of domesticated plants, to understand some of the most critical discussions that contributed to the reinterpretation of domestication under the Darwinian proposal of modified descent.

"From the Known to the Unknown:" Nature's Diversity, Materia Medica, and Analogy in 18th Century Botany, Through the Work of Tournefort, the Jussieu Brothers, and Linnaeus.

The growth of botany following European expansion and the consequent increase of plants necessitated significant development in classification methodology, during the key decades spanning the late 17th to the mid-18th century, leading to the emergence of a "natural method." Much of this development was driven by the need to accurately identify medicinal plants, and was founded on the principle of analogy, used particularly in relation to properties. Analogical reasoning established correlations (affinities) between plants, moreover between their external and internal characteristics (here, medicinal properties). The diversity of plants, names, and botanical information gathered worldwide amplified confusion. This triggered the systematisation of the collection and referencing of data, prioritizing the meticulous observation of plant characteristics and the recording of medicinal properties as established by tradition: it resulted in principled methods of natural classification and nomenclature, represented by the genus, to enhance reliability of plant knowledge, which was crucial in medical contexts. The scope of botany increased dramatically, with new methods broadening studies beyond traditional medicinal plants. The failure of chemical methods to predict properties, particularly of unknown flora, amplified the reliance on analogy and on natural affinities.

Ateleological propagation in Goethe's Metamorphosis of plants.

It was commonly accepted in Goethe's time that plants were equipped both to propagate themselves and to play a certain role in the natural economy as a result of God's beneficent and providential design. Goethe's identification of sexual propagation as the "summit of nature" in The Metamorphosis of Plants (1790) might suggest that he, too, drew strongly from this theological-metaphysical tradition that had given rise to Christian Wolff's science of teleology. Goethe, however, portrayed nature as inherently active and propagative, itself improvising into the future by multiple means, with no extrinsically pre-ordained goal or fixed end-point. Rooted in the nature philosophy of his friend and mentor Herder, Goethe's plants exhibit their own historically and environmentally conditioned drives and directionality in The Metamorphosis of Plants. In this paper I argue that conceiving of nature as active productivity-not merely a passive product-freed Goethe of the need to tie plants' forms and functions to a divine system of ends, and allowed him to consider possibilities for plants, and for nature, beyond the walls of teleology.

John Hill (1714?-1775) on 'Plant Sleep': experimental physiology and the limits of comparative analysis.

The phenomenon of 'plant sleep' - whereby vegetables rhythmically open and close their leaves or petals in daily cycles - has been a continual source of fascination for those with botanical interests, from the Portuguese physician Cristóbal Acosta and the Italian naturalist Prospero Alpini in the sixteenth century to Percy Bysshe Shelley and Charles Darwin in the nineteenth. But it was in 1757 that the topic received its earliest systemic treatment on English shores with the prodigious author, botanist, actor, and Royal Society critic John Hill's The Sleep of Plants, and Cause of Motion in the Sensitive Plant. As the present article aims to illustrate, Hill and his respondents used this remarkable behaviour, exhibited by certain plants, as a lens through which to reassess the nature of vegetables, and to address pressing questions of wider natural philosophical import, particularly the degree of continuity between the structures and functions of plants and animals and whether similar mechanisms necessarily account for related movements in different life forms. These disputes, this paper contends, also had profound methodological implications regarding the proper way to conduct experiments, the extent to which it was acceptable to extrapolate from observations, and the status of causal explanations.

Remembering Melvin Calvin (1911-1997), a highly versatile scientist of the 20th century.

Melvin Calvin (1911-1997) was the recipient of the 1961 Nobel Prize in Chemistry for the discovery of the canonical photosynthetic carbon reduction cycle. We present here a very brief glimpse of this extraordinary American scientist, who in his time was a preeminent force in physical and organic chemistry. Besides natural photosynthesis, Calvin's prolific career included artificial photosynthesis, colors of organic substances, the origin of life, cancer, moon rocks, molecular basis of learning, and plant lipids & algal hydrocarbons as potential renewable sources of transport fuels.

The Control of Cell Expansion, Cell Division, and Vascular Development by Brassinosteroids: A Historical Perspective.

Steroid hormones are important signaling molecules in plants and animals. The plant steroid hormone brassinosteroids were first isolated and characterized in the 1970s and have been studied since then for their functions in plant growth. Treatment of plants or plant cells with brassinosteroids revealed they play important roles during diverse developmental processes, including control of cell expansion, cell division, and vascular differentiation. Molecular genetic studies, primarily in Arabidopsis thaliana, but increasingly in many other plants, have identified many genes involved in brassinosteroid biosynthesis and responses. Here we review the roles of brassinosteroids in cell expansion, cell division, and vascular differentiation, comparing the early physiological studies with more recent results of the analysis of mutants in brassinosteroid biosynthesis and signaling genes. A few representative examples of other molecular pathways that share developmental roles with brassinosteroids are described, including pathways that share functional overlap or response components with the brassinosteroid pathway. We conclude by briefly discussing the origin and conservation of brassinosteroid signaling.

Of elephants and errors: naming and identity in Linnaean taxonomy.

What is it to make an error in the identification of a named taxonomic group? In this article we argue that the conditions for being in error about the identity of taxonomic groups through their names have a history, and that the possibility of committing such errors is contingent on the regime of institutions and conventions governing taxonomy and nomenclature at any given point in time. More specifically, we claim that taxonomists today can be in error about the identity of taxonomic groups in a way that Carl Linnaeus (1707-1778), who is routinely cited as the "founder" of modern taxonomy and nomenclature, simply could not be. Starting from a remarkable recent study into Linnaeus's naming of Elephas maximus that led to the (putative) discovery of a (putative) nomenclatural error by him, we reconsider what it could mean to discover that Linnaeus misidentified a biological taxon in applying his taxon names. Through a further case study in Linnaean botany, we show that his practices of (re)applying names in taxonomic revisions reveal a take on determining "which taxon is which" that is strikingly different from that of contemporary taxonomists. Linnaeus, we argue, adopted a practice-based, hands-on concept of taxa as "nominal spaces" that could continue to represent the same taxon even if all its former members had been reallocated to other taxa.

Darwinian Evolution's First 50 Years of Impact on Medicine and Botany at the University of Toronto, 1859 to 1909.

Prior to Darwin's masterworks, a university professor of medicine's purview generally included the professorship of botany and direction of the botanical gardens. Yet from the landmark 1876 Johns Hopkins model and especially after the 1910 Flexner Report, botany was limited at certain medical schools to (exaggerating somewhat) "decorating their lobbies!" Darwinian-era scientific paradigms spread from continental Europe through promulgators such as Huxley and Osler, transforming laboratory research, disease aetiology, biochemical therapeutics, and clinical "bedside" teaching. Unintended consequences at universities with medical schools might include altered loyalties and resources among competing disciplines. At the University of Toronto, botany vis-à-vis medicine was gradually treated as passé or secondary to zoology for modern, scientific platforms. This pattern was not universal; botany strongholds at universities such as Harvard continued to flourish. Where a negative perspective took hold with evolutionary impacts, botanists' careers became limited and the impetus for maintaining botanic research and teaching facilities such as a university botanical gardens was impaired.

An Historical Review of Phenylacetic Acid.

Plant hormone biology is an ever-evolving field and as such, novel avenues of research must always be sought. Technological and theoretical advancement can also allow for previously dismissed research to yield equally interesting insights into processes now that they are better understood. The auxin phenylacetic acid (PAA) is an excellent example of this. PAA is a plant auxin that also possesses substantial antimicrobial activity. It has a broad distribution and has been studied in bacteria, fungi, algae and land plants. Research on this compound in plants was prominent in the 1980s, where its bioactivity and broad distribution were frequently examined. Unfortunately, due to the strong interest in the quintessential auxin, indole-3-acetic acid (IAA), research on PAA quickly petered out. Recently, several groups have resumed investigations on this hormone in plants, yet, little is known about PAA biology and its physiological role is unclear. PAA biosynthesis from the amino acid Phe invites direct comparisons with previously studied IAA biosynthesis pathways, and recent work has shown that PAA metabolism and signaling appears to be similar to that of IAA. However, given the large gap between previous work and recent investigations, a historical review of this auxin is required to renew our understanding of PAA. Here, previous work on PAA is reassessed in light of recent research in plants and serves as a synthesis of current knowledge on PAA biology.

The phyllotaxis of the aortic valve.

Biological systems ubiquitously and inevitably exhibit stochasticity in traits from the molecular level to the multicellular and morphological level. However, there are several examples of natural events that might be described in mathematical terms. Plants grow in a structured and geometric way to maximize their sun exposure for photosynthesis while reducing the stress. The 'Fibonacci sequence' and its 'golden ratio' are considered a mathematical regularity and model that is one of the corner-stone of the 'phyllotaxis', the part of the botany that studies how plants branch. Nevertheless, we currently do not know if such mathematical model can be applied to humans. Different authors have hypothesized that 'fractal' might be identified along with the 'golden-ratio' in the human body (coronary artery, heart valves etc.). The aortic valve and the aortic root might represent an interesting model of human fractal geometry, where the phyllotactic rules can be reasonably applied, and where deviation from normality might results in dysfunction. However, in the absence of scientific validations, such report represents only the authors' perceptions of a beautiful shape.

Networked names: synonyms in eighteenth-century botany.

This paper addresses early modern botanical nomenclature, the practices of identifying and publishing synonyms in particular, as a collaborative "information science". Before Linnaean nomenclature became the lingua franca of botany, it was inevitable that, over time, the same plant was given several names by different people, which created confusion and made communication among botanists increasingly difficult. What names counted as synonyms and actually referred to the same plant had to be identified by meticulously comparing living and dried specimens of this and similar plants as well as relevant illustrations und descriptions in the botanical literature. Identifying synonyms required and generated an ever-expanding mass of data, which was used continuously to adjust and rearrange plant names. Despite the greatest care, judgements on synonyms were not definitive, which meant that published lists of synonyms for individual species of plants were in a state of flux and had to be constantly updated, corrected, and rewritten. This required long-term international collaborations, the accumulated results of which were not published once but consecutively, in augmented and corrected editions of a book. As a result of this networked approach, synonyms are networked names that reflect the epistemic interconnectedness of the botanical community. These questions will be discussed with a focus on the Dutch botanist Johannes Burman (1706-1779), who placed synonyms at the centre of his work as posthumous editor-and co-author-of the botanical manuscripts that were left behind by other botanists.

'And Eden from the Chaos rose': utopian order and rebellion in the Oxford Physick Garden.

Abel Evans's poem Vertumnus (1713) celebrates Jacob Bobart the Younger, second keeper of the Oxford Physick Garden (now the Oxford University Botanic Garden), as a model monarch to his botanical subjects. This paper takes Vertumnus as a point of departure from which to explore the early history of the Physick Garden (founded 1621), situating botanical collections and collecting spaces within utopian visions and projects as well as debates about order more widely in the turbulent seventeenth-century. Three perspectives on the Physick Garden as an ordered collection are explored: the architecture of the quadripartite Garden, with particular attention to the iconography of the Danby Gate; the particular challenges involved in managing living collections, whose survival depends on the spatial order regulating the microclimates in which they grow; and the taxonomic ordering associated with the hortus siccus collections. A final section on the ideal 'Botanick throne' focuses on the metaphor of the state as a garden in the period, as human and botanical subjects resist being order and can rebel, but also respond to right rule and wise cultivation. However, the political metaphor is Evans's; there is little to suggest that Bobart himself was driven by utopian, theological and political visions.

An interview with Caroline Dean.

Caroline Dean is a plant biologist based at the John Innes Centre in Norwich, UK. She helped to establish Arabidopsis as a model plant organism, and has worked for many years on the epigenetic mechanisms that regulate vernalisation, the process by which plants accelerate their flowering after periods of prolonged cold. We met Caroline at the recent Spring Meeting of the British Society for Developmental Biology. We asked her about her career, her thoughts on the plant field and being awarded this year's FEBS EMBO Women in Science Award.