Apr 252018
 

Today is sometimes called World DNA Day although it is not an official holiday for any organization. It commemorates the day in 1953 when James Watson, Francis Crick, Maurice Wilkins, Rosalind Franklin and colleagues published papers in the journal Nature on the structure of DNA. Furthermore, on this date in 2003 (the 50th anniversary) it was declared that the Human Genome Project was very close to complete, and “the remaining tiny gaps” were considered too costly to fill. I have often used the first paper on DNA published by Crick and Watson (originally 2 handwritten pages), as a caution to my students that a paper does not have to be long to be good. Of course, Crick and Watson were not anthropology undergraduates. Some scientific or mathematical discoveries can be put on paper briefly, because that is one of the hallmarks of science itself – reducing complex datasets to elegant and simple equations or formulae. At one level, the structure of DNA is simple to understand; it is the ramifications of that structure that are so wondrously complex and fascinating.

With an “alphabet” of just four nucleotides that form pairs at the center of the DNA molecule – cytosine [C], guanine [G], adenine [A] and thymine [T] – we can “spell” the genetic code of every living thing on earth. The implications of this fact completely revolutionized biology (and allied sciences) in my lifetime. DNA analysis changed the way we think about species and evolution for starters.  With DNA analysis we can plot the exact lines of the development of species and the relationships between them. Both old taxonomic systems of species and the lines of their evolution have been upended by the introduction of DNA analysis. The broad strokes remain the same, of course, but there has been an enormous amount of shuffling around inside those broad strokes. DNA has also confirmed what anthropologists have known for a long time: race is not a biological fact. Human biological variation exists on a continuum and, therefore, there are no biological markers – DNA or otherwise – for specific races. Race is a cultural, not a biological, classification system.

DNA analysis was as important an additional to the criminal forensic science toolkit as fingerprinting was 100 years ago. In fact, DNA matching is much more accurate that fingerprinting and has been used, not only to convict criminals, but also to free the wrongly convicted (including from death row). Analysis of DNA can be used to identify potential medical hazards for an individual, and some methods are available now for repairing DNA. Without doubt, the identification of the structure of the DNA molecule was the single biggest step forward in the biological sciences in the 20th century. What was known very well by the scientific community, but less well known by the general public, is that Crick and Watson should be given a great deal of credit, but by no means all of it, for the discovery.

Isaac Newton was not being very original when he said, “If I have seen further than others, it is by standing upon the shoulders of giants,” but he was displaying suitable humility. James Watson was not quite so humble when he wrote The Double Helix: A Personal Account of the Discovery of the Structure of DNA, published in 1968. When I read it, shortly after it was published, I was struck by Watson’s arrogance, not to mention his obvious sexism. Since then I have noted that I was far from alone in that opinion. As Watson notes, repeatedly, the race was on in the early 1950s to be the first to publish an accurate account of the structure of DNA, and this was not a particular priority for Crick. The race to be the first in certain scientific fields can be intense because the rewards, in terms of money, prestige, and influence, are so high. Great minds can disagree as to whether competition is the best road to discovery. It is certainly the norm in Western science, deriving from cultures that seem to thrive on competition.

In The Double Helix, Watson acknowledges, but downplays, the contributions of others in the search for the structure of DNA, and occasionally makes egregious, and unwarranted, remarks, such as his comment that Rosalind Franklin, whose research was vital for Crick and Watson’s final discovery, was not quite attractive enough to be called “pretty.” What does that remotely have to do with anything? He never says anything about the appearance of male colleagues. I could say that Francis Crick has the appearance of a bad Spike Milligan impersonator, but you would not, on the basis of that remark, think I had keen insight into anything – scientific or otherwise.

The Nobel committee was, thankfully, more open minded than Watson in awarding the prize jointly to Crick, Watson, and Maurice Wilkins. Nobels may be shared by no more than three scientists, and they must be living at the time of the award. These conditions excluded Rosalind Franklin (who had died) and Raymond Gosling, her graduate assistant, whose X-ray diffraction imagery of the DNA molecule was fundamental to Crick and Watson’s breakthrough. Today’s anniversary celebration in this post is not of the original announcement of the discovery, which was made in the Eagle pub in Cambridge on 28th February, but of the publication in Nature of related papers by Crick and Watson, Maurice Wilkins, Rosalind Franklin and Raymond Gosling, and others, acknowledging the need for collaborative effort to achieve significant results.

Understanding the structure of DNA has led to genetic engineering technologies in a variety of fields. One of the best-known and controversial applications of genetic engineering is the creation and use of genetically modified crops or genetically modified livestock to produce genetically modified food. Crops have been developed to increase production, increase tolerance to abiotic stresses, alter the composition of the food, or to produce novel products.

The first genetically modified crops to be grown commercially on a large scale provided protection from insect pests or tolerance to herbicides. Fungal and virus resistant crops have also being developed or are in development. This make the insect and weed management of crops easier and can therby increase crop yield. GM (genetically modified) crops that directly improve yield by accelerating growth or making the plant hardier (by improving salt, cold or drought tolerance) are also under development. In 2016, salmon were genetically modified with growth hormones to reach normal adult size much faster.

GMOs (genetically modified organisms) have been developed that modify the quality of produce by increasing the nutritional value or providing more industrially useful qualities or quantities.] The Amflora potato produces a more industrially useful blend of starches. Soybeans and canola have been genetically modified to produce healthier oils. The first commercialized GM food was a tomato that had delayed ripening, increasing its shelf life.

This site fascinates me, although its claims seem a bit far-fetched, and they could use a decent copy editor: https://thespoon.tech/personalizing-food-directed-by-your-dna/  The Commonwealth Scientific and Industrial Research Organization (CSIRO), has just launched a three-year study into the personalized fabrication of smart food systems. The basic idea is to examine a person’s DNA, find any flaws in it, and then – via technology not yet invented – create foods that are optimal in restoring that person’s DNA to health. Imagine that you have a machine, perhaps rather like a refrigerator, that takes a blood sample, analyzes it, than manufactures foods for your next meal that are perfectly matched to your current genetic needs. This machine would be something like a 3-D printer, except that instead of making objects it would make foods. Sounds like something out of the Jetsons, I know, and I expect that the technology is still some way in the future despite the optimism of the writers.

There are 2 things that trouble me about this sci-fi scenario. First, I do not trust biochemical engineers to come up with the right food for me from a machine. Bioengineering does not have a great track record, and there are countless mistakes that have been made. Second, rather related to the first, I cannot imagine a machine-made food product more satisfying – nor healthier –  than the food I buy from markets and cook for myself. I may be unusual, but I do not believe I am unique in paying attention to my day-to-day appetites for finding the foods that are the best choices for my body at that moment. Surely everyone at one time or another has had the experience of getting sick, hankering after specific things (or nothing at all) and, it turns out, those foods are what the body needs in those circumstances to get better. I am well aware that this is not a trustworthy system by any means, but I believe we could do a lot better by uncovering natural physiological solutions to our dietary needs, than dreaming of a food-making machine.

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