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A Salute to Sir John Burdon-Sanderson and Mr. Charles Darwin on the Centennial of the Discovery of Nerve-like Activity in the Venus' Flytrap
Abstract
http://www.carnivorousplants.org/cpn/articles/CPNv02n3p41_43.pdf
Supplementary resource (1)
... Darwin was not only one of the first Honorary Members of the Physiological Society, he was an enthusiastic supporter of physiological experimentation and collaborated with the cardiac physiologist John Burdon Sanderson on experiments using the Venus fly trap (Williams, 1973) published in 1873 (Burdon Sanderson, 1873) and with George John Romanes, described in the history of the Society (Sharpey-Schafer, 1927) as 'Of all the young men who helped to launch the Society, Romanes was unquestionably the most brilliant.' Romanes bravely tried to resist the tide of Weismannism. ...
Life is purposefully creative in a continuous process of maintaining integrity; it adapts to counteract change. This is an ongoing, iterative process. Its actions are essentially directed to this purpose. Life exists to exist. Physiology is the study of purposeful living function. Function necessarily implies purpose. This was accepted all the way from William Harvey in the 17th century, who identified the purpose of the heart to pump blood and so feed the organs and tissues of the body, through many 19th and early 20th century examples. But late 20th century physiology was obliged to hide these ideas in shame. Teleology became the ‘lady who no physiologist could do without, but who could not be acknowledged in public.’ This emasculation of the discipline accelerated once the Central Dogma of molecular biology was formulated, and once physiology had become sidelined as concerned only with the disposable vehicle of evolution. This development has to be reversed. Even on the practical criterion of relevance to health care, gene-centrism has been a disaster, since prediction from elements to the whole system only rarely succeeds, whereas identifying whole system functions invariably makes testable predictions at an elemental level.
... Darwin was not only one of the first Honorary Members of the Physiological Society, he was an enthusiastic supporter of physiological experimentation and collaborated with the cardiac physiologist John Burdon Sanderson on experiments using the Venus fly trap (Williams, 1973) published in 1873 (Burdon Sanderson, 1873) and with George John Romanes, described in the history of the Society (Sharpey-Schafer, 1927) as 'Of all the young men who helped to launch the Society, Romanes was unquestionably the most brilliant.' Romanes bravely tried to resist the tide of Weismannism. ...
Life is purposefully creative in a continuous process of maintaining integrity; it adapts to counteract change. This is an ongoing, iterative process. Its actions are essentially directed to this purpose. Life exists to exist. Physiology is the study of purposeful living function. Function necessarily implies purpose. This was accepted all the way from William Harvey in the 17 th century, who identified the purpose of the heart to pump blood and so feed the organs and tissues of the body, through many 19 th and early 20 th century examples. But late 20 th century physiology was obliged to hide these ideas in shame. Teleology became the 'lady who no physiologist could do without, but who could not be acknowledged in public.' This emasculation of the discipline accelerated once the Central Dogma of molecular biology was formulated, and once physiology had become sidelined as concerned only with the disposable vehicle of evolution. This development has to be reversed. Even on the practical criterion of relevance to health care, gene-centrism has been a disaster, since prediction from elements to the whole system only rarely succeeds, whereas identifying whole system functions invariably makes testable predictions at an elemental level. ADDITIONAL KEYWORDS: biological function-Central Dogma-purpose in biology-teleology. FUNCTION IN PHYSIOLOGY Physiology is concerned with function in living organisms. It is from this study of function that teleology, the study of purpose, emerges as an equally necessary tool of analysis. We begin this paper with some examples of quantitative functional analysis in order to demonstrate how understanding the physiological functions of life leads to predictions concerning molecular and other lower-level processes, whereas the reverse is rarely true.
... Darwin hypothesized that action potentials were involved as he could paralyze a tentacle in Drosera by cutting its 'nerve.' He sent flytraps to the eminent physiologist Sir John Burdon-Sanderson who confirmed nerve-like rapid depolarization in Dionaea (Burdon-Sanderson, 1873;Williams, 1973). Although Darwin faced opposition and controversy for advancing notions (based on simple 'country house experiments') that plants transmit and respond to stimuli like animals (Morton, 1981;de Chadarevian, 1996), we witness here the emergence of experimental plant physiology. ...
Among carnivorous plants, Darwin was particularly fascinated by the speed and sensitivity of snap-traps in Dionaea and Aldrovanda. Recent molecular work confirms Darwin's conjecture that these monotypic taxa are sister to Drosera, meaning that snap-traps evolved from a 'flypaper' trap. Transitions include tentacles being modified into trigger hairs and marginal 'teeth', the loss of sticky tentacles, depressed digestive glands, and rapid leaf movement. Pre-adaptations are known for all these traits in Drosera yet snap-traps only evolved once. We hypothesize that selection to catch and retain large insects favored the evolution of elongate leaves and snap-tentacles in Drosera and snap-traps. Although sticky traps efficiently capture small prey, they allow larger prey to escape and may lose nutrients. Dionaea's snap-trap efficiently captures and processes larger prey providing higher, but variable, rewards. We develop a size-selective model and parametrize it with field data to demonstrate how selection to capture larger prey strongly favors snap-traps. As prey become larger, they also become rarer and gain the power to rip leaves, causing returns to larger snap-traps to plateau. We propose testing these hypotheses with specific field data and Darwin-like experiments. The complexity of snap-traps, competition with pitfall traps, and their association with ephemeral habitats all help to explain why this curious adaptation only evolved once.
New findings:
What is the topic of this review? To revisit 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 trans-generational 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. The article outlines research lines by which this could be achieved. This article is protected by copyright. All rights reserved.
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