How the Ju|’hoan Make Poison Arrows

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A modified version of a map in a paper by Caroline S. Chaboo, Megan Biesele, Robert K. Hitchcock, Andrea Weeks

When I was a child, my grandmother taught me how to make arrows from the softwood of a poplar, a tree that was abundant in the woods that we could step into from my backyard. Later in adolescence, biased from the movies that I watched,  I perceived arrows to be “primitive”.

It is another case of truth differing from popular perception.

Human ancestors were hunter-gatherers millions of years ago, but archery appeared relatively late, around 65 000 years ago. To make arrows far more effective hunting weapons, humans have learned to extract poisons from plants, frogs and beetles. Unfortunately, indigenous communities across the planet who hunt with arrows are gradually becoming sedentary and are losing traditional knowledge. They include  some native North American Indians; Paraguay’s Ache; the Pumè in Venezuela; the Hadza in Tanzania and 113 000 people of various San communities (use “click” languages) from Angola to South Africa (see map). Some San groups are the only ones in the world who are known to use beetles to make their poison arrows. Based on their local conditions, these invariably isolated communities have developed their own specialized poison use and preparation.

Authors of a 2016 study, focused on two San groups from Namibia: the Ju|’hoan and Hai||om. The former who live near Nyae Nyae told researchers that, thanks to older hunters, they had learnt to locate plants of the genus Commiphora, which are host to the larvae of two beetle species shown below.

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At margin of the shrub, using either a metal stick or a traditional wooden one, the hunter either digs a new 1 meter ditch encircling the plant or extends that of a preexisting one. ( (1) in picture set below)  The hunter uses his finger to sift the loosened sand with his fingers, straining out the beetles’ oval-shaped cocoons . When enough cocoons have been collected into an ostrich egg shell or plastic container (2), the hunter heads home.  The hunter makes sure that the concave surface of an animal knuckle bone faces upwards in the sand in front of him, and he places the beetle cocoons nearby. A small fire is lit. He breaks open a cocoon and taps out the single larva (3), discarding any pupae and adult insects.  Using a stick as a pestle, he rubs hard against the skin to loosen tissue, then extracts it to mix on the bone mortar (4), using about 10 larvae for every arrow. He chews the bark of Acacia mellifera to produce saliva which is mixed with the larval tissue and their “blood”, hemolymph. A bean of the toxic snake bean plant (Bobgunnia madagascariensis)  is heated over the fire, cooled and added to the mixture. Ju|’hoan informants at|Xai|Xai in Botswana told one of the researchers that they use the juice of Sansevieria plants to improve the poison. Without touching the poisonous mix, the hunter applies the ‘beetle paste’ of D. nigroornata larva with a twig to the dried sinew that fastens the arrowhead to the shaft.  The arrows are then finally dried. Their poison becomes less potent with time and expires within a year.

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The poison is a  protein known as diamphotoxin. As far as proteins go, it is very small and simple structure. It’s a single chain polypeptide with a molecular weight of only 60000 grams per mole. The poison is a so-called ionophore, affecting the permeability of red blood cells. Many small ions, including those of calcium (Ca2+), enter indiscriminately. The wounded animal’s red bloods, about 75% of them, then burst.  This leads to a severe shortage of oxygen throughout the body. The release of ions from ruptured cells also wreaks havoc in kidneys. Convulsions, paralysis, and death ensue. As far as natural poisons go, diamphotoxin is highly potent. Whereas the lethal dose that kills 50% of animals (LD50) for chlorotoxin (scorpions), nicotine, amatoxin (amanita mushrooms) and frogs’ batrachotoxin (from poison dart) is 4.3, 3.3 , ~0.5 and ~0.002 mg/kg, respectively, diamphotoxin’s is only 0.000000025 mg/kg (25 picograms/kg) for mice. That implies that one gram of pure diamphotoxin would be enough to kill (50%)*(1012 pg/g)*(kg/25pg)*(mouse/0.020 kg) = one trillion twenty-gram mice. 

Although the San groups have no molecular explanations for their weapon of choice, in order to develop the method of preparation, they have performed a type of laboratory science, with all its trial and error. And just like with modern science, it took a leap of imagination to think of extracting the poison from an insect’s larvae in the first place. Unfortunately, unlike practitioners of  Western science, the San groups have not left any written records of how and what their previous generations have discovered.

Sources: 

Chaboo and Al. Beetle and plant arrow poisons of the Ju|’hoan and Hai||om San peoples of Namibia. Zookeys Feb 01, 2016 958: 154

Harpe and Al. Diamphotoxin. The arrow poison of the !Kung Bushmen. Journal of Biological Chemistry. October 10, 1983 258, 11924-11931.

Jacobsen and al. Effect of Diamphidia toxin, a bushman arrow poison, on ionic permeability in nucleated cells. Toxicon Volume 28, Issue 4, 1990, Pages 435-444

 

Other LD50 data: https://web.archive.org/web/20150412045434/http://biology.unm.edu/toolson/biotox/representative_LD50_values.pdf

 

Economics Vs. Environment: A False Dichotomy

mid-globeThe false dichotomy of economics versus environment has long existed because it is unfortunately too easy to sweep health and environmental costs under the rug or to have government consistently pick up the bill for consequences of short-sighted “growth”.

Here’s a letter sent to the Economist by former World Bank, senior vice president, Vinod Thomas, specifically arguing that by addressing climate change we are really safeguarding the economy in the long run.

It is true that climate change is not just an environmental problem; it cuts across all activities. Yet the recipe for economic growth from mainstream economists, including those of the The Economist newspaper, disregards climate change.  Yes economic textbooks cover externalities or spillover effects, but these have not been integral to growth analysis. A search finds abundant climate studies, but less than 0.5% of the numerous growth articles over the past 50 years seem to factor climate effects.

That allows politicians such as Jair Bolsonaro, Brazil’s president, to argue that environmental protection is inimical to growth,even as the emerging reality is the opposite. American policy too, sees any deregulation, including policy that mortgages the environment, as pro growth. Yes environmental destruction may boost short term growth, but the climate outcomes hurt long term growth and welfare.

So changing the conduct of growth economics is essential if we are to avert a climate catastrophe.Unless the economics profession stops ranking and rewarding countries based primarily on how much they deregulate and boost short term GDP, the climate action that you rightly call for will continue to lag dangerously.

Here is another discussion from the journal Nature that is more detailed and broader in scope:

The cost of a warming climate

 

Storks and the Biological Facts of Life

Many years ago, I got into the good habit of keeping a journal while my kids were growing up. Here’s one of my favorite entries. 

My daughter, who is in the first grade, went to an art museum with her class today. She told her Mom that lots of statues were showing their private parts. In the morning she had also showered with her mother, so not surprisingly, my daughter came out of it saying she wants breasts.

284613678011211Kids, of course, occasionally think of precocious thoughts that simply float away. But I cannot help contrast her childhood to mine. I never showered with the parent of my own sex; in fact, luckily, I have yet to see my parents naked. When my mother was pregnant with my brother, I was my daughter’s age, and I had seen a picture of a stork that held, from its beak, a sling with a baby. There were fluffy clouds in the background, and that’s where my brother was coming from—the sky.

One day, our tenant’s daughter, Manon, claimed that my baby brother was in my mother’s belly. I remember exactly what crack of the sidewalk I was about to step on when she said that. Manon had made the world stop. I recall looking across the street at the front entrance, expecting my mother to magically open the door and promptly deny the absurdity. It was like being told that the milk came out of the milkman’s ear.

Luckily, later that evening, after laughing and realizing that I was not ready for the truth, my mother assured me that a stork would indeed bring the baby home. Astonishingly, even though I know from recent accounts that my mother had apparently remained relatively thin throughout the pregnancy, I had never noticed her belly. My brother was not exactly born hamster-sized, so I must have never looked below her face.

Five years later in the sixth grade, my friend, whose first name was the same as mine, came to school with a shocking piece of news. As we walked past the nun’s residence, he quoted a World Book Encyclopaedia article on reproduction. It claimed the process started when a male part of the anatomy was placed in the female counterpart. How could that lead to a baby? Could unscrewing the back of a TV and sticking a prosciutto ( ham) into it create a cooking show? But half the boys in our class seemed to confirm what was in print, and the encyclopaedia had never lied to me. I wrestled with the idea for a week, considering the possibility that a secret had been kept from me. But accepting the idea became more difficult when the same friend had concluded that this was only one way of reproducing. Surely, our parents had used some other means.

A few weeks ago my daughter, who has a fascination with bones, was looking at some anatomy drawings in one of our medical books. She turned the pages and came across a diagram of a scrotum and asked what it was for. It produces seed needed to make a baby, I told her. “That’s how babies are made?” she asked, grimacing. I realized that I had told her too much.

Our children need their childhood.

 

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