Zebra Finches At a STEM Conference

In the spring of 2016, I attended a STEM conference. Expanding the acronym as science, technology, engineering and math doesn’t shed too much light on the intentions and philosophy of STEM.  The premise is that math, science and technology subjects should not be taught in isolation; there should be more integration and emphasis on applications. All of this is largely inspired by the job market’s need for a larger number of better-trained people in these specialised fields. It all seems reasonable as long as the approach is not taken to an extreme.

A society, regardless of its bent, functions best when a wide range of talents are cultivated, even if they seem to serve no practical purpose. Similarly, we have a healthier situation in schools and colleges when educators don’t sail on the same ship. There was at least one organiser at the conference who shared my views because a particular lecture went against the grain of STEM.  95% of the auditorium featuring the lecture was empty and attended mostly by the speaker’s university students, a couple of bird-lovers and a little cluster of Canada Wide Science Fair attendees. Rudely, the latter group even walked out before it ended. But if you stick to the premise that attendance at public events is very often inversely proportional to its quality, you don’t worry about numbers.

Parentese or “baby talk“ is far from being just indulgence on the part of parents. In humans it helps draw attention from babies and promotes the learning of speech. Regardless of language, there are universal characteristics of parentese. Voice pitch is modulated; speech is slower, more repetitive and more attention-grabbing than adult-talk.

Image of baby zebra finch from http://www.singing-wings-aviary.com/zebrafinches.htm

A similar situation arises in a small Australian bird known as the zebra finch. For those of you unfamiliar with the small bird, one of its distinguishing characteristics is its song, which is reminiscent of the squeaky sound of a rubber duckie. With their form of baby talk, adult zebra finches change their vocalisations when singing to young birds. They slow them down and use more repetition. The juvenile finches in return pay more attention to such songs than to those used between adults.In their young lives, they the simpler versions. With time, in the physical presence of adults, the chick’s song converges with that of their tutor. When zebra finches were isolated and exposed to mere recordings, they developed different songs.

The social interaction between tutor and chick stimulates communication between the midbrain’s ventra legmental area (VLA) and regions of the cerebrum. The VLA is partly a reward centre and uses dopamine.  When humans acquire language, neural bridges of that type are also made. In case of the finch, the evidence for such a pathway comes from the fact that in the absence of tutor’s physical presence, a marker for gene expression of catecholamines (which include dopamine) remained inactive.

Another revelation which made my morning was that the zebra finch researcher had originally majored in economics, reinforcing my notion that to get to an island you don’t have to board any specific boat.


The History of DDT Through an Ellulian Lens

We rarely see the word technique used in the Ellullian sense of the word. Coined by Jacques Ellul in the 1950s when Technological Society was first published, technique refers to an ensemble of methods embedded in every field of human activity. These methods are rationally arrived at and seek efficiency. By such a definition, technique does not only include machines, robots and electronic technology but also economic systems, military and advertising strategies, human resources and management of government departments, corporations and research labs. In technique, spontaneity and tradition are replaced by a complex set of acts with the aim to achieve some kind of quantifiable goal. While technical progress grows irreversibly and exponentially, its far-reaching effects on the human psyche, physiology, culture and environment cannot all be foreseen. It’s through this lens that we’ll examine the history of the pesticide dichlorodiphenyltrichloroethane, abbreviated as DDT.

ddt-spray-beach.jpgIn order to encourage living scientists to continue their excellent work, Nobel Prizes are never awarded posthumously. The problem with that restriction is that a discovery’s full impact on its field and society is usually not immediately apparent. And unfortunately there is no minimum time that has to elapse between publication of the achievement and the granting of the award. One year before the Nobel committee committed its biggest blunder by awarding the 1949 Prize for Medicine for the lobotomy, the 1948 Prize for Medicine was awarded to Paul Müller “for his discovery of the high efficiency of DDT as a contact poison against several arthropods.” DDT had been first synthesized back in 1874 by Zeidler, but Müller found uses for the compound in the 1930s while searching for a contact poison against clothes moths and carpet beetles.  In his acceptance speech, Müller mentioned the heavy World War II outbreak of typhus in Naples in October 1943. Three months later, 1.3 million people were sprayed with DDT over a period of 3 weeks.

An Epidemic Typhus species, the type of louse that was killed by DDT.

The poison was not absorbed through human skin but killed body lice which were infected with the cause of typhus fever, Rickettsia prowazekii. The disease, which otherwise would have had about a 40% mortality rate, was brought under control. Hundreds of thousands of lives were saved.

Once technique was involved in war, with its tentacles spread over weaponry, strategy, propaganda and economics, the effects became devastating on an unprecedented scale.  Typhus was more likely to develop in an already poor area impacted by such a war. And often the only way to deal with problems exacerbated by technique is with more technique, which in this case was, again in Müller ‘s words, “an introduction by General Fox of DDT with total exclusion of the old, slow methods of treatment.”

After the war, DDT also became an effective way of fighting malaria by attacking their vector, the Anopheles mosquito. By 1967 endemic malaria was wiped out in Greece, Italy and in many subtropical Asian and Latin American countries. It should be pointed out that draining breeding grounds in those areas also played a key role in eradicating the disease. This wasn’t possible in tropical areas in Africa where, in addition, the necessary infrastructure for a spraying program was often lacking. Consequently only a few African countries participated. A couple of years later, it was learned that some mosquito populations were becoming resistant to DDT.

Insect resistance should not have come as a complete surprise. In accepting his prize almost twenty years earlier, Muller had stated:

Generally speaking the housefly is very susceptible to DDT; unfortunately some fairly resistant species of fly have lately been observed. 

It turns out that within any species being treated with any insecticide, there will always be a few individuals who escape death. These survivors are the ones who continue to reproduce, so they will leave behind more of the genes that made them less vulnerable. (Some recent evidence suggests that only a single gene may be required.) After many generations—and it doesn’t take very long; in a single year mosquitoes can go through 25 to 70 life cycles—a once-rare trait becomes the norm.

C14H9Cl5 : 1,1′-(2,2,2-trichloroethane-1,1-diyl)bis(4-chlorobenzene) aka dichlorodiphenyltrichloroethane aka DDT

That wasn’t the only issue with DDT.  It’s highly resistant to light and oxygen and to organisms’ mixed-function oxidase
enzymes (MFOs), which normally oxidize and break down fat-soluble toxic substances. Other enzymes can convert DDT to DDE by replacing a chlorine and a hydrogen from the middle of the DDT molecule with a double bond. But DDE is still toxic and is  even more resistant to the action of MFO enzymes. In other words we can consider DDT not to be biodegradable overall. Moreover DDT’s and DDE’s strong tendency to dissolve  in lipids(100 g/L for DDT at room temperature) and not in water (only 2μg/L for DDT) means that fat tissue can act as a sponge: an organism’s intake of DDT will exceed the amount excreted. This mechanism repeatedly increases concentration of the toxin as one organism eats another. The higher the organism is in the food chain, the more DDT it will have in its fat tissue. Populations of high trophic predators such as eagles and falcons were affected when DDT was used heavily as a pesticide. The accumulated poison in their tissue interfered with steroid metabolism. Affected birds became incapable of moving enough calcium into their eggshells.  As the thin shells cracked, their embryos were killed by the entry of bacteria. Along with unrelated pressures that had been placed on the birds, DDT led to their precipitous decline.

Although written in the 1950s Ellul’s Technological Society already mentioned DDT’s unforeseen effects on mammals—there was research revealing DDT’s impact on bones of newborn calves. I couldn’t find any later work that corroborated such a claim, but DDT is eliminated far more slowly in cattle than in humans. Without further input, the half life of DDT in humans is 69 days but 335 days in cattle based on lactation studies in 1965 by RC Laben. More recently (2011), adults with high serum concentrations of organochlorine pesticides such as DDT have been found to have lower vitamin D levels. Although DDT is not a category 1 carcinogen, it is classified as a probable carcinogen based on animal studies. And there are other serious health concerns to be considered. A few years ago, a Lancet review study of the health risks and benefits of DDT stated that indoor application of DDT could be effective in some settings of malaria-infested areas. But they also pointed out that through continuous spraying, mothers could carry a body burden of DDT, which raises the risk of preterm birth and early weaning. Other risks such as neurological effects could also affect mothers and workers receiving and applying the spray, respectively.

Organizations currently dedicated to abating malaria seem to be using a variety of strategies. Non-DDT alternatives have been used in eave tubes, which cause mosquitoes to get fooled into entering the tubes as they follow the CO2 trail coming from human inhabitants inside the homes. Along with better built houses, these have helped control malaria in Tanzania. Elsewhere this approach is being combined with sugar traps and sterilisation of male mosquitoes.

After the second world war, clothes sprays contained a 5% solution of DDT to kill moths. The same compound was included in moth balls.

What made DDT a serious problem was the scale of its application, a recurring theme when it comes to technique. First used as an insecticide in 1939, it eventually became one of the most ubiquitous pesticides on the planet from 1946 to 1972. It was used on cotton, fruits, potatoes and corn to kill worms, moths, beetles and borers, respectively. Aside from its use against life-threatening diseases such as malaria and typhus, it also served as an agent against far less serious pests such as moths in clothes and insects in museum specimens. With such overzealous applications it’s no surprise that by the mid 1960s human breast milk across the planet suddenly contained twice the maximum levels set by WHO (World Health Organization). These levels were equal to the concentrations needed to cause biochemical changes in rats. Soon after, Sweden issued a two-year moratorium of DDT. The eventual cancellation of DDT’s registration by the USA’s Environmental Protection Agency in 1972 was based on human health concerns, not directly on ecological grounds. From Public Health Reports:

Hayes, a witness for the state, declared DDT safe on the grounds that soldiers sprayed with it in the 1940s and prisoners who swallowed it in studies performed in the 1950s had suffered no adverse effects. Lawyers and witnesses for the petitioners dismantled Hayes’ testimony by focusing on the human health questions left unanswered by such studies: DDT’s long-term toxicity; its effects on the endocrine system and liver; and its effects on newborns, children, and women.

DDT also inspired the synthesis of similar organochlorine pesticides, most of which are fortunately banned today due their toxicity and environmental persistence. The worst of the bunch were the cyclodiene pesticides, which unlike DDT, were absorbed through the skin. Even at low doses these compounds induced convulsions. Meanwhile in a reasonable position, the World Health Organisation supports the ban on DDT in most countries while concluding:

that countries that are relying on DDT for disease vector control may need to continue such use until locally safe, effective, affordable and environmentally sound alternatives are available for a sustainable transition away from DDT.

Needless to say there are many influential people who disagree with Ellul’s analysis of technique. They find the concept too fuzzy and his tone excessively pessimistic. His dismissers include those who believe that DDT should never have been banned anywhere, even if the countries were malaria-free. Oddly some DDT-enthusiasts even villify Rachel Carson, author of Silent Spring, even though, as we mentioned previously, the decision to deregister DDT in the United States was not directly based on environmental concerns. Like Hayes, they are “couched in a political view that remained faithful to a vision of the U.S. as the superpower and global protector it became in the years after WWII.” While not acknowledging the existence of technique’s web, they also feel society does more harm than good by trying to stifle or regulate technology. (Ironically the regulating bureaucracies are part of Ellul-defined technique.) Ellul was not at the opposite end of the spectrum. He was apolitical and certainly never felt that we should get rid of technology; he realised that its abandonment would be suicide for our species. Instead he expressed the need to transcend it. How could that happen? If we remain scientific while letting more than just a trickle of ecological and spiritual sense flow through our beings, we will be on more benign and autonomous tracks.*

*The fact that the word “track” initially came to my mind in the singular, is one of so many reminders of how narrow our points of view can be when contemplating our futures. There was a time, not too long ago, when different civilisations coexisted, unaware of the others’ existence and travelling a variety of paths.

Continue reading “The History of DDT Through an Ellulian Lens”

From Playing Cards to Clover

If we keep looking at the same thing over a period of time with an uncritical, non-curious or distracted mind, attenuation sets in. And not only do our nervous systems tune out what’s commonplace, we also develop a false sense of history. We act as if things always were as they currently appear to be, and as if they will continue to be immune from flux.

Take playing cards as an example. If one was raised in North America and was not in contact with recent Spanish, Moroccan or Italian immigrants, it’s likely that the person has a fixed image of playing cards: 52 cards, 13 in each of four suits: clubs (clover), hearts, spades and diamonds with three of the cards being a king, queen and a jack.

The four suits of Neapolitan playing cards like those of other Spanish and Italian cards differ from French ones.  The former’s suits are far more similar to those of the first cards imported into Europe from Egypt in the 14th century. Pic by the author.

But these familiar cards are just one version, one that originated under the rule of  King Charles VI of France between 1380 and 1422. They continued to evolve a little later in the 15th century into their current forms which are neither unique nor static.  Take a tour of  cafes in Italy and you will see people playing with variations upon the theme of Italian-Spanish cards:  the king is still present, but there is a cavalier and a servant instead of the queen and jack, respectively. And there are only 40 cards with suits of clubs (large sticks), cups, swords and coins. These strike more of a resemblance to the first cards that were imported into Europe by Italian merchants around 1360. They discovered them while trading with Mamluks in Egypt. The cards had the same suits like those of contemporary Spanish and Italian cards, except that they featured a wand instead of a club.  Regional cards in Northeastern Italy still include a wand as a suit.

I often wondered why the word “club” is used for the clover leaf, one of the four suits of French cards. One hypothesis is that the suit was associated with commoners who grew clover alternately with their crops for fodder and in order to enrich the soil. But wooden clubs were also commoners’ weapon of choice, so the name “clubs” stuck to clover.

Clover is a legume whose roots include a mutualistic relationship between bacteria and plant cells.

The arrows point to white clover’s root- nodules, the site of nitrogen fixation by mutualistic bacteria. (The scale is in inches. 1 inch = 2.54 cm) Picture from NC State Extension Publications – NC State University

Thanks to bacterial enzymatic action, valuable nitrogen compounds are made from otherwise unusable nitrogen air molecules. In exchange, the bacteria receive shelter and sugars. Before many people developed the bad habit of adding herbicide to lawn grass, white clover seed  was often mixed with grass seed. Clover, when coexistent, helps grass by adding nitrogen compounds to the soil.

Like playing cards, not all clovers are alike. White clover is adapted to moist conditions. It should not be the only companion of lawn grass. Especially where grass grows on slopes where water drains easily, it makes more sense to grow bird’s foot trefoil. Scientifically known as Lotus corniculatus , it is another leguminous plant which does better in arid conditions and which will help abate dandelions. These unpopular relatives of the lettuce in turn out-compete grass when less water is available. A smaller legume with smaller yellow flowers, black medic, can do well in both moist and more arid soils. And of course there is a common origin to the genera of the bird’s foot (Lotus), to medic (Medicago) and to that of at least 238 Trifolium species, including red and white clover—-we see it in the similarity of leaflet shape, small pea-like flowers and to the all-important and welcome infection in their productive roots.

Clover and clover-like plants belonging to 3 different genera of the legume family: from left to right, Trifolium repens (white clover), Lotus corniculatus (bird foot’s trefoil) and Medicago lupulina (black medic). Just about all Trifolium species are bee-pollinated. All pics from wikipedia commons.

Their family Leguminosae evolved about 56 million years ago, 9 million years after large dinosaurs went extinct. A few million years later, their most important clades separated. From genetic analyses, it’s been determined that their evolution occurred quickly, reminiscent of  the way playing cards quickly branched out in Europe. And like the latter,  the 18000 species of legumes are now spread all over the planet. They are being used for food, oil, lumber, fiber, medicines, aesthetic purposes and not least of all, for a vital role in the Earth’s nitrogen cycle.


Lavin, et al. 2004. Evolutionary Rates Analysis of Leguminosae Implicates a Rapid Diversification of Lineages during the Tertiary. Systematic Biology 54 (4): 530-549 http://sysbio.oxfordjournals.org/content/54/4/575.full

The Botanical Garden. Phillips and Rix

The Mediterranean and Mediterranean World. Francois Braudel

The four suits of a pack of cards www.theguardian.com/books/booksblog/2013/dec/04/books-advent-calendar-4-four-card-suits

Have you ever wondered why the symbols on playing cards are called…. http://www.brierfieldbridgeclub.org.uk/themes/Have%20you%20ever%20wondered.htm


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