Taxonomic Technology: Electrophoresis & Classification in Agricultural Botany (Part 1)

My second ever work-in-progress seminar at the University of Leeds introduced attendees to the second chapter of my PhD, which examines the use of laboratory machinery and biochemical methods to identify and analyse crop varieties at the National Institute of Agricultural Botany (NIAB) during the 1980s. By the late-twentieth century, classifying agricultural plants was a difficult task. More and more varieties were submitted to NIAB by plant breeders, while the distinguishing characteristics of varieties grew smaller and smaller. Identifying and classifying varieties had traditionally relied upon botanically-trained observers. Yet visual scrutiny of plants’ morphological characteristics was problematic, requiring both considerable expertise and grown specimens.

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The problem of classifying of agricultural plants is demonstrated by these images of celery varieties. Each column here represents a distinct variety: the correct classification of these samples by eye would be a near-impossible task for the untrained observer. From G.W. Horgan, M. Talbot and J.C. Davey, ‘Plant variety colour assessment using a still video camera’, Plant Varieties and Seeds (1995) 8: 161-169.

An escape route was provided to NIAB via a form of protein fingerprinting developed in biochemistry: electrophoresis. For historians of biology, electrophoresis is best known for its use by Lewontin and Hubby to break an impasse in population genetics during the 1960s. Electrophoresis was trialed at NIAB during the same period, to little avail. Matters changed during the early years of the 1980s, when staff at NIAB’s Chemistry and Quality Assessment Branch were able to apply electrophoresis to cereal varieties. Electrophoresis works by running an electric current through a gel in which a sample sits. As different proteins carry different charges, they separate into distinct “bands” (see below).

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An early image of a completed electrophoresis sample. The darker protein “bands” can be seen once the gel is chemically dyed. From R.P Ellis, ‘The identification of wheat varieties by the electrophoresis of grain proteins’, Journal of the National Institute of Agricultural Botany (1971) 12: 223-235.

Electrophoresis provided a new means of classifying agricultural plants and was promoted in NIAB’s publications as an efficient and modern technique of variety identification. The experience of the Institute during the 1980s chimes with what historians of science have termed the “molecularisation movement” in the life sciences. This movement is usually associated with genetics and the role of DNA and nucleic acids. Yet historians have called for broader studies under the theme of molecularisation, not least because of the broad use of terms such as “molecular biology” by scientists themselves. Financial gain and prestige came from NIAB’s research into electrophoresis; the technique still appears in guidelines issued by international agricultural bodies today, despite the rise of DNA sequencing. Yet electrophoresis was not the only method of classification investigated by NIAB during the 1980s, as future posts will explore…

 

 

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Gregor Mendel & Scientific Fraud: iHPS Workshop, University of Durham (Part 2 of 2)

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On the second day of the iHPS workshop at the University of Durham, Professor Greg Radick (University of Leeds) delivered his keynote address “Is Mendel’s Evidence “Too Good to Be True”? This year has seen the one hundred and fiftieth anniversary of Mendel’s two 1865 lectures “Experiments in Plant Hybridisation,” with many drawing a line directly from Mendel’s findings to modern biotechnology. Yet two ghosts exist at the Mendelian feast: the specter of eugenics and the accusation that Mendel fraudulently obtained data. Or as Ronald Fisher termed it, that Mendel’s results were “too good to be true.”

Mendel’s 1865 findings are known to many of us. Hybridising garden peas in his monastery garden revealed a reoccurring pattern of three-to-one in second-generation hybrids. In later generations, traits reversed, with gametes receiving heredity information randomly. If we flip a coin multiple times and always end up with an exact fifty-fifty split, eyebrows would be raised. In a 1902 paper by W.F.R. Weldon, statistical analysis of Mendel’s data revealed such a trend, as the latter’s result accorded remarkably with his hypothesis. The chances of Mendel arriving at his results by pure coincidence was placed by Weldon at sixteen-to-one. In 1911, Ronald Fisher spoke at the Cambridge University Eugenics Society on Weldon’s findings. By this time, Mendelian genetics has been established beyond controversy and integrated with Darwinian natural selection. At this talk and in a later 1936 paper, Fisher declared that Mendel regarded his experiments as an empirical demonstration of his conclusions. Mendel was no mere experimentalist – though his results were still fake. Fisher laid the blame at the feet of one of Mendel’s assistants, who had doctored experimental results to please his master.

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Drawing upon affair, Professor Radick noted that Mendel’s peas were not intended to be “true-to-nature,” but represented absolute qualities. For historians of science, the episode suggests that a more thoughtful, systematic approach to scientific fraud is needed. We should also be aware of different approaches to genetics offered by historical figures such as Weldon, who emphasised the interaction of genes with each and other and the environment. In fact, recent results from Leeds HPS Genetic Pedagogies Project suggest that students placed on a Weldonian-style genetics course emerge less convinced of genetic determinism than their Mendelian peers.

Field & Laboratory – Darwin in the Ottoman Empire – Chinese Biology & Goldfish

Other associates of Leeds HPS also presented well received papers on the history of biology. Cultivating Innovations (http://www.cultivatinginnovation.org/) postdoc Dominic Berry (@HPSGlonk) spoke on the historical division of field and laboratory, drawing upon randomised control trials at the National Institute of Agricultural Botany (NIAB). Visiting fellow Alper Bilgili (@BilgiliEnglish) described the reception of Darwinism in the Ottoman Empire. Darwin was enthusiastically embraced by some westward-leaning Turkish intellectuals who greatly admired the scientific method – while others sought to integrate Darwinism with traditional religious beliefs. Lijing Jiang (@LijingJiang), who (all too briefly) visited Leeds for some weeks, spoke on Chinese biologists’ investigations into genetics and evolution from the early-twentieth century. In contrast to the experimental cultures of many Western universities, Chinese biologists who studied native goldfish drew upon historical accounts to reconstruct the animals’ evolutionary past.

Laboratory to Field: Agriculture & the Practical Applications of Botany in 1946

In 1946, a textbook aimed at agricultural students was published, entitled Principles of Agricultural Botany. The author was Alexander Nelson, Lecturer in Plant Physiological and Agricultural Botany at the University of Edinburgh. Nelson brought the principles of plant science to bear on agriculture, a process which he believed would in turn shape farming practice. Nelson’s textbook emerged from a much older scientific tradition, which had closely linked training in practical botany with the raising and identification of crops.

Of course, the marriage between botany and agriculture had been a long-standing affair. European naturalists had routinely recorded the utilitarian aspects of exotic plants, whether for agriculture, horticulture or medicine. The formation of botanical laboratories during the second half of the nineteenth century, particularly in Germany, would seem to mark a separation of  the theoretical and practical in botany. But this was not the case – Cittadino (2009) has noted that figures such as Marshall Ward (1854-1906), chair of botany at Cambridge, obtained laboratory training in Germany before accepting a colonial post in Ceylon to study diseases on coffee plantations.

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A study on the inflorescence of different crops in Nelson’s textbook, p. 227.

Across the Atlantic, a move from botanical training to agriculture was equally apparent. Since the mid-nineteenth century, university-trained botanists had taken up posts at agricultural colleges and experimental stations. In the United States, the relationship between plant ecologists and agricultural scientists was especially close. Ecological principles were a useful tool in identifying new lands suitable for cultivation. Nelson’s textbook stated the principle as recognising that “the plants occurring naturally in any area will tend to be the types most suited to the environment there.” Grasping this basic axiom of species distribution could inform botanists which crops would be likely to succeed where. A wider understanding of biological communities also had a utilitarian role, in terms of combating pests (or at least those animals considered as such).

Nelson’s 1946 textbook certainly seemed to bridge the divide between laboratory and field. On the one hand, the book was illustrated with numerous photographs of microscope slides. However, in an address aimed at student readers, Nelson also cautioned against book learning. Instead, readers were informed “You yourself must see, draw, describe, and as far as possible experiment until you recognize a specimen or phenomenon in the same way as you recognize an acquaintance – by familiarity.” Beside individual acquaintance with plant life, the tacit knowledge of growers was another valuable resource:

“In all your reading and study be critical. When statements made by authorities appear to conflict with one another or with observations or your own, you should refer to the object itself, to experimentation, or to the practical man on the land, who often has the facts though perhaps not the scientific explanation.”

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Cell division under the microscope in Nelson’s textbook, Plate 4.

As my PhD focuses on goings-on at the National Institute of Agricultural Botany on the eve of the so-called “biological revolution,” these developments are particularly pertinent. Many of the principle skills outlined in Nelson’s textbook were apparently rendered unnecessary by new technology. One example was the identification methods to distinguish crop varieties, which by the 1970s could be conducted via protein analysis. It will be interesting to find out what changes occurred in botanical training as these new technologies emerged. Of equal importance shall be the distinction between laboratory and field work, or at least the perception of this distinction.

Considering the importance of agriculture to the development of botany (and vice versa), this seems like a theme ripe (pardon the pun) for examination.

Further Reading

Cittadino, Eugene, “Botany,” in Peter J. Bowler and John V. Pickstone (eds.) The Cambridge History of Science: The Modern Biological and Earth Sciences, Vol. 6. (Cambridge: Cambridge University Press, 2009): 227-242.

Hersey, Mark D., “What We Need is a Crop Ecologist”: Ecology and Agricultural Science in Progressive-Era America,” Agricultural History 85 (2011): 297-321.

Nelson, Alexander, Principles of Agricultural Botany, London: Thomas Nelson and Sons, 1946.

How Agricultural Science Struggled to Defuse the Population Bomb

Another talk! So many talks recently… But this time I was back with the welcoming home crowd at the University of Leeds, finally presenting on my PhD thesis! I began this seminar by recounting an extraordinary speech at the National Institute of Agricultural Botany’s (NIAB’s) 1972 Seed Analyst Conference. Presented by the then vice-president of the National Farmer’s Union (NFU) D.H Darbishire, the keynote address was littered with poignant phrases. The “undernourished of all mankind” were suffering as the “Doom debate” raged in industrialised nations, which were in turn a facilitator of the dichotomy between the “affluent minority and disinherited majority” of the global population.

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Edward S. Deevey, Jr. “The Human Population,” in Paul R. Ehrlich, John P. Holdren & Richard D. Holm, Man and the Ecosphere (San Francisco: W.H. Freeman and Company, 1971), p. 49. Original printing in Scientific American, 1960.

Why was Darbishire using a Seed Analysts Conference organised by a Cambridge-based agricultural institute to espouse these views with such urgency? Well, in the same year that Darbishire spoke out, the Club of Rome’s The Limits to Growth published a computer simulation of human society and the environment, declaring that the growing world population was living beyond its means. This was only the latest in a series of “neo-Malthusian” themed texts, all of which declared that the globe was fast approaching its human carrying capacity.

Such a claim was by no means new in the post-war era. In 1948 ecologist William Vogt’s Road to Survival predicted that world population would crash under the weight of its own numbers, subsequently wiping out three-quarters of humanity. This claim was given new urgency by the 1968 publication of Paul Ehrlich’s The Population Bomb. Here, the claim was made that in agricultural terms, “the stork had passed the plough.” In 1966 world population had increased by seventy million, with no compensatory increase in food production.

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Ecology teaching slides from the University of Wisconsin-Madison Archives, Robert McCabe Papers, 1971.

Agricultural science could clearly respond to this (perceived) crisis by endeavoring to increase global crop yields. Steps had been made in the right direction with the “Green Revolution,” high-yielding hybrid crops being passed onto developing nations – albeit with the associated package of chemicals, intensive irrigation and management. However, tracts like The Limits to Growth predicted these gains would soon be overrun by an exponentially growing human population. Higher yielding varieties had to become better, while regulatory institutions like NIAB had to test and promote them faster.

However, intensive monocultures of high-yielding crop varieties had vulnerabilities. Ehrlich had classed these setups as prone to ecological collapse, an opinion shared by many ecologists. Industrialised agriculture was certainly susceptible to common plant diseases like rusts and mildew. Darbishire blamed the practices of plant breeders, who sought to overcome pathogens by focusing on single, major genes. Instead, it might be better to concentrate on “a number of more humble genes.” A genetics arms race with disease strains would bring few benefits.

Clearly, the world faced problems in agriculture, genetics and the environment. How could one institution like NIAB go about responding to these problems? The Institute’s journal certainly carried multiple articles applauding increases in domestic food production across the 1970s. But actions speak louder than words. While NIAB was able to recommend crop varieties with high yields or disease resistance, its work was hindered by the increasing need for disease testing and changing regulatory standards via Britain’s 1973 entry into the European Economic Community (EEC).

At NIAB, cereal yields were portrayed as falling from their peak in the 1950s, due to a mysterious “soil microbiological interaction.” presumably the 1970s equivalent of vital forces or phlogiston theory. Later in the decade, yields were considered to be rising, but at a slow pace. On the disease front, more progress was made, with genetic solutions stepping in for pesticide use (which had taken a battering since the 1962 publication of Rachel Carson’s Silent Spring). Genetic diversity was urged in fields by NIAB officers in a 1979 newsletter, the same year seeing the publication of geneticist Norman Simmond’s textbook Principles of Crop Improvement, which also called for genetic diversity and conservation.

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NIAB at work today! The 2014 Cereals Event, Cambridgeshire. Shoddy photography courtesy of the blogger.

In the event, an imminent Malthusian catastrophe turned out to be a false alarm. Although, such concerns continue to crop up (pardon the pun) in modern fears over food security – after all, the global community is still no stranger to famine. From the perspective of an environmentalist, the trend towards crop diversity and genetic conservation as the 1980s approached certainly sounds promising. However, against the background of all this, recombinant DNA  technology was making great strides. On June 16th 1980, in the case of Diamond vs. Chakrabarty, the US Supreme Court ruled five to four that manmade microorganisms were patentable inventions. Later that year, the prototype biotech company Genentech went public, experiencing a huge demand for its stock on Wall Street. A new chapter on food and environmental controversy was just opening…

Further Reading:

Ainsworth, G.C., Introduction to the History of Plant Pathology (Cambridge: Cambridge University Press, 1981).

Ehrlich, Paul R., The Population Bomb (New York: Buccaneer Books, 1968).

Meadows, Donella H. Dennis L. Meadows, Jørgen Randers and William W. Behrens, The Limits to Growth: A Report for the Club of Rome’s Project on the Predicament of Mankind (London, Pan Books Ltd, 1972).

Schoijet, Mauricio, “Limits to Growth and the Rise of Catastrophism,” Environmental History 4 (1999): 515-530.

Silvey, Valerie and P.S. Wellington, Crop and Seed Improvement: A History of the National Institute of Agricultural Botany 1919 to 1996 (Cambridge: National Institute of Agricultural Botany, 1997).

Simmonds, Norman W. Principles of Crop Improvement (New York: Longman, 1979).