Monthly Archives: August 2020

!Kung Hunter-gatherers: Gender roles, diet and…wait, what? Birth control?

by Sivanesan N. Dharmalingam 

There was a time when all humans lived as hunter-gatherers. Not that I’m about to detail the complex evolution of Homo sapiens, but let’s just say that we all have origins that trace back to a time long before city life. In this time our ancestors would trek across the African plains to hunt animals for meat, which they would bring back to camp and feed their families, along with vegetables, fruit and nuts foraged from around the camp. Now when we hunt, it’s for the best deals on the best brands and foraging is confined to the (sometimes) not-so-fresh produce from local supermarkets, all conveniently accessible at the shopping-mall closest to us.

Figure 1: Nomadic men leaving camp to hunt an animal, staple in their diet of the !Kung for ~11 000 years – the nocturnal springhare (2).

One of the few hunter-gatherer societies that still exist today are the !Kung, of south-west Africa.
Yes, that is where the exclamation mark is supposed to go – it indicates that there is an alveolar-palatal-click at the beginning of the word. Place the tip of your tongue on the roof of your mouth, behind your teeth and sharply draw it backwards… !Kung..!Kung. Awesome, lets continue:
For over 11 000 years most of the !Kung had hunter-gatherer lifestyles, hunting some of the same animals since the Pleistocene, until about 50 years ago. Now, less than 5% of ~30 000 !Kung people still practice this lifestyle in the 21stcentury. Most population groups have adopted an agrarian (practice cultivation of land for farming) lifestyle, having settled down near Bantu (pastoralists – cattle herders) villages. This rapid social change is accompanied by social, dietary and demographic changes. These changes are interesting, anthropologically, since they might possibly reflect some of the changes that occurred during the Neolithic revolution, which saw a wide-scale pattern of previously nomadic peoples establishing permanent settlements (transitioning from hunter-gatherers to agrarian lifestyles) and the development of social class and civilisation(~12 000 years ago).

Some of the most interesting differences between nomadic bands and the settled peoples are related to the changes in behavior, status and the role of !Kung women. In nomadic bands, men leave camp to hunt for meat, whilst women – responsible for foraging – are as mobile as the men and contribute ~50% of the food for the band from foraging. Their diet is widely acclaimed as being nutritional and well-balanced and is reported that very few nutritional and even old-age related deficiencies and disease (associated with complex societies) existed in these peoples. Both sexes equally contribute to sustenance of the group and as such, these women  are autonomous and they have higher egalitarian status, which give them the ability to directly influence group decisions. Some men and women stay behind everyday to care for children and maintain the camp.
YES!!! Finally, a society which treated both sexes equally!
However, with the transition to sedentary lifestyles, the !Kung women are losing their egalitarian status. The men of the sedentary !Kung leave their villages to work –  farming and herding cattle on Bantu farms. Women remain, preparing food (a shift to include cow’s milk and grain) and caring for the village and the children; not mobile, contributing less to the food supply and therefore are more reliant on the men. !Kung men learn the language(s) and practices of the Bantu when working on the farms. They echo the ideals of the male-dominated Bantu society into their own and the Bantu-people only deal with the !Kung men, creating increasingly subservient roles for the women.

Children are raised differently in settled !Kung villages. In nomadic bands, there aren’t groups based on age and sex. The children play together in a non-competitive environment, where distinct gender roles and aggression are discouraged and actively avoided.  In the settled villages there is an increase in population size (more children) and groups of same sex and similar ages for playing, which breeds competition. I must admit that last sentence quite accurately depicted my high-school experience. The boys are on their own, expected to herd cattle and learn farming.

Figure 2: group of nomadic !Kung children, depicting mixed ages (3).

The girls have no comparable experience and help women, in the village, with chores. The increase in population sizes are attributed to the increase in body size of the settled !Kung, which is due to the increase in food supply. The nomadic bands have a natural birth control – the menarche (first menstrual cycle) of girls occur later (~16 years old) and women have babies less frequently, with a woman’s first birth around 19-20 years old and an average birthing interval of 4 years. This is related to food supply – body fat percentage must exceed a minimum for onset, and maintenance after, menarche. Due to the lack of soft food, children are nursed for ~4 years and in those years the lactating woman may have too little body fat for ovulation to occur and she rarely falls pregnant in this time. Settled groups have 30% shorter birthing intervals and have more children, owing to the introduction of cow’s milk and grain meal into the infants’ diet.

There is no confirmation that the !Kung peoples transition from hunter-gatherers into agrarian societies are an accurate representation of the events of the Neolithic revolution. However, I personally find the social egalitarianism and equality of gender roles portrayed by the nomadic bands of the !Kung fascinating! The idea that a simple lifestyle revolving around basic needs had, and – in the few societies that remain – have equality of sexes brings to attention that social classes, and a gender biased society are not “a thing of the past”, but rather completely out of place in the progression of our species. In our society today, where women and men have equal potential, the opportunity to contribute to our advancement should be afforded to all.


  1. Kolata, G.B., 1974. ! Kung hunter-gatherers: feminism, diet, and birth control. Science185(4155), pp.932-934.
  2. Lee, R.B., Lee, R.B. and DeVore, I. eds., 1976. Kalahari hunter-gatherers: Studies of the! Kung San and their neighbors. Harvard University Press.
  3. Hawkes, K., O’Connell, J. and Blurton Jones, N., 2018. Hunter‐gatherer studies and human evolution: A very selective review. American journal of physical anthropology165(4), pp.777-800.

Guard your heart, it’s Covid-19

By Kutlwisiso Setlogelo

Covid-19 is a severe disease that has claimed the lives of millions across the world without the development of effective treatment to stop it.  It has been reported that comorbidities increase the likelihood of developing serious and fatal outcomes. Particularly, cardiovascular disease (CVD) which is a group of heart and blood vessel disease including diabetes and high blood pressure, have featured most commonly in Covid-19 patients who have been in critical care or have demised. It is thus suggested that there is a link between a history of CVD and the outcome of Covid-19. However, this is deeply concerning because CVD in itself is the leading cause of death and disability globally. Therefore, urgent investigations need to be done to understand how SARS-Cov-2 further threatens the health of those with CVD.

A study by Nishiga et. al looked into several investigations that has been done up to this point. Research shows that Sars-Cov-2 exacerbates heart disease by causing further heart damage, giving rise to a heart attack. In fact, the rate of death due to Covid related-heart attacks is doubled in patients with a history of heart disease. So, what exactly is the mechanism? ACE2 is a receptor found on heart cells that allows for the invasion of Sars-CoV-2. With this said, samples were taken from the heart to assess if the heart damage was because of direct invasion of the virus. Only some studies found the virus in the heart cells as well as some immune cells which was suggestive of direct attack. Other studies suggest that the progression of heart attacks may be due to the reduction of ACE2 that happens after the cells are infected. The loss of ACE2 has been attributed with the narrowing of blood vessels, which compromises the supply of nutrients to the heart, leading to heart attack. The narrowing of the blood vessels is accelerated in the patients with uncontrolled diabetes and high blood pressure which explains why the rate of death is highest among these patients infected with SARS-Cov-2. Furthermore, other studies show that the immune response against Sars-Cov-2 may also contribute to affecting the flow of blood to the heart. With this said, if you are known to have a history of heart problems or have diabetes and high blood pressure, it is preferable that you stay at home. Given the fact that health resources are limited and a cure is unavailable, the only safe thing to do for oneself is to diligently follow regulations and restrictions because your life may depend on it.


Wu, J. C. (2020) ‘COVID-19 and cardiovascular disease: from basic mechanisms to clinical perspectives’, Nature Reviews Cardiology. Springer US. doi: 10.1038/s41569-020-0413-9.

Fitzmaurice, C. et al. (2019) ‘Global, regional, and national cancer incidence, mortality, years of life lost, years lived with disability, and disability-Adjusted life-years for 29 cancer groups, 1990 to 2017: A systematic analysis for the global burden of disease study’, JAMA Oncology, 5(12), pp. 1749–1768. doi: 10.1001/jamaoncol.2019.2996.










Bringing dead myocardium back to life

by Megan Rajah

Myocardial Infarction (MI) refers to the irreversible death of cardiomyocytes (specialized cardiac muscle cells) secondary to ischaemia; which is usually caused by an atherosclerotic obstruction in one or many coronary arteries that supplies oxygen and nutrients to the heart muscle. The illness has found itself under the global spotlight for the last few decades as it has taken the wheel in driving morbidity and mortality in a significant proportion of the population in both developing and developed countries (1).

The clinical implication of a MI is an impairment in the cardiac contrac- tility that eventually culminates in cardiac failure. Currently, the only available treatment for cardiac failure is the use of a combination of commercially available drugs that control symptoms but fail to address or reverse the physical damage to the myocardium (1). This has sparked a generation of scientists to investigate the potential offered by Stem Cells and Biomaterials to regenerate the damaged myocardium (4)

A recent study by Kashiyama et al, has been accepted for publication in the Journal of Thoracic and Cardiovascular Surgery and shows promise in this area of research. The study investigated two different materials that have previously been described: Cell sheets and cardiac (scaffold) patches. What they did differently, however, was that they combined the two techniques and compared its efficacy to each method alone (4).

How did they do it? Adult stem cells were isolated from the adipose located in the Inguinal region of mice. After 10 days of standard stem cell culture, the cell aggregates were plated into wells and given 48 hours to form a cell sheet. For the cardiac patches, porcine hearts were decellularized and the extracellular matrix components were extracted and then electrosprayed onto a biodegradable polymer scaffold. The left anterior descending (LAD) coronary artery was surgically ligated in mice to induce MI. The mice were then treated with either (i) cell sheet (ii) cardiac patch (iii) cell sheet + cardiac patch and (iv) sham surgery (4).

An illustration summarizing the important steps taken to generate the therapeutic materials. Illustration created in BioRender.

What were their findings? After 8 weeks, mice treated with cardiac patches alone or in combination with cell sheets had a significantly smaller area of fibrosis in the damaged myocardium compared to the sham group and mice treated with cell sheets alone. A functional assessment by echocardiography (cardiac ultrasonographic investigation) showed that the three treatment groups had significantly im- proved their left ventricular ejection fraction (LVEF) compared to the sham group. Furthermore, of the three, the improvement was great- est in the arm treated with combination therapy (LVEF improved from roughly 30 to 50%). This group also demonstrated signs of better angiogenesis (and hence, reperfusion), therefore allowing for oxygen and nutrient supply to the repairing myocardium (4).

For science and medicine, this holds great promise. Both materials alone were capable of improving outcomes and when combined, those improvements were even more significant. As promising as this sounds, it is important to bear in mind that the long term benefits and risks have yet to be established. In the past, human trials involving cardiac regeneration have not always produced sustainable improvements and the immunogenicity of these materials has yet to be completely characterized.

The underlying mechanism of this therapy is also still up for debate. Potentially, myocardial regeneration occurs therefore replacing the damaged tissue or the constructs contain important molecular factors that save/protect the existing tissue from severe ischaemic damage. While it may take several years to understand and perfect the therapy, its likely to revolutionize the field and change patient lives while re- ducing drug costs and drug burdens. It certainly is exciting and I look forward to watching it progress!


  1. Myocardial Infarction: Practice Essentials, Background, Definitions. 2020.
  2. Cardiovascular diseases. World Health Organisation. 2020.
  3. Cardiovascular Disease Statistics Reference Document. 2016.
  4. Kashiyama, N., Kormos, R., Matsumura, Y., D’Amore, A., Miyagawa, S., Sawa, Y., & Wagner, W. R. (2020). Adipose derived stem cell sheet under an elastic patch to improve cardiac function in rats after myocardial infarction. The Journal of Thoracic and Cardiovascular Surgery.

“To Be or Not to Be” (To Do): That is the Question

by Mbalentle Madlala

I’m sure many of us have heard the quote in the above title sometime in our lives, regardless of whether we can specifically pinpoint when and from where we did. The quote actually comes from the famous William Shakespeare’s Hamlet, one of his many so-called “tragedies”, or plays. Perhaps you may have noticed my brief addition to the quote, indicated in brackets. I trust my reason for this will be evident later in the text.

Being able to start off this reflection with this quote makes me feel really philosophical and reflective indeed, haha. But trust me, starting off this way is not just for the sake of being dramatic, oh no. As I begun to formulate my thoughts in order to write this piece, I found that this is a statement that is relevant and that summates my experiences as an honours student during these unprecedented times we currently find ourselves in.

So 2020 was going to be MY year. My year to live in the city and experience all the adventure it holds whilst pursuing scientific knowledge and experience in the form of an honours degree at the prestigious University of Cape Town. My life would evolve around this – it would be high up on my list of “Important things Mbali does in life”. A significant pursuit to tick off before attending to any other thing I wish to do, any other pursuit of the soul. Make sure I “secure the bag” and all the things. That was the expectation.

But that’s not how the story actually played out. Don’t get me wrong – my experience at UCT, although brief, has exceeded my expectation. I honestly feel like it was the springboard to why I’ve come this far in my science, my writing, my world view, my occupational confidence, my current way of thinking. But I digress.

No one could’ve imagined how the year subsequently played out (as I’m sure you’ve heard several times). Who knew I’d be living the life I described above at home? I mean, how does one continue to “live in the city + experience it + pursue science at UCT”, a pursuit that my life was supposed to evolve around, at home?

Exactly. One doesn’t.

I wasn’t devastated though. My “free bird” nature, as I like to call it, allows me to go with the Spirit and be at peace with things I can’t change. Rather, I was challenged. Like I had to ask myself, “what is life now?” “What am I within life?” And with all the more time on my hands, “what do I do?” “Who do I be?” “How shall I be, and subsequently, do?”

These questions led me on a journey of questioning whether what “I do” gives more meaning to me than what “I be”. At the beginning of the year, my “being” – Mbali – translated to my “doing” – pursuing science at UCT. That time Mbali has many other facets and many other parts to her. Many other interests and many other loves. But, perhaps unknowingly, I was willing to put it all on hold to secure the bag. Which isn’t entirely a bad thing – stay with me. BUT, now that I know that that is what I was going to do, is it really what I wanted? Do I still want that? Was this forced time at home about to teach me a thing or two about Being, apart from just Doing (Not Being) ?

And then issues concerning privilege and position, poverty, injustice, racism, xenophobia, heart conditions and corruption, violence and classism etc. started being highlighted more deeply in society because of the circumstances. All of it played massive roles in the above described journey I now consciously found myself in. Whilst pursuing my love for science and health care and taking care of my responsibilities during the journey, I would now pursue other issues I care about more intently. With a wholistic approach. Doing the necessary heart work and introspection required to challenge my internal biases. Challenge my world view. Reflect on why I’m actually on this earth and why I chose to pursue the current occupation I find myself in. BE better so that I could DO better. Not just one or the other.

Disclaimer: it’s pretty hard. Like it’s weird and challenging and humbling and requires vulnerability and openness and embarrassment and a heart to learn with the possibility of being wrong. But dang! I really be liking the girl I’m learning about in the process (AKA me) and because of this, I can be a better contribution to society, to my research, to my people, to my country.

I’ve found myself joining leadership courses, learning about expression at writing labs and even running (I say “running” very cautiously) a whole entire comrades marathon (like the most randomest things) as a result of this journey. Consequently, I’ve been impacted by so many random people and places and things and webinars and phone calls and zoom meetings, all from my dining room table/bed at home. I’ve stepped out and collaborated and created and shared and asked for help and helped others. I’ve given time to things my soul enjoys (though feeling guilty, then proceeding to ask myself why) and things I haven’t done in a minute. I’ve prioritised others. I’ve dug deep and remembered what’s important to me and how important people are – way more than anything I could ever simply do. I’ve done things that scare me. I’ve spoken to my mama about things I never thought I ever would. I could go on.

All this, in itself, is a privilege, I see that. I take responsibility for that. And it never would have happened had all this madness not happened. Wild.

Basically the message I guess I’m trying to get across to YOU (well done for getting this far in reading some of my crazy reflections on paper) is to check again – Who are you and what do you stand for? What is important to you – do you do it? Will you be it? And from this place, how can you live a more integrated balanced life? In all you do. Then, relate these thoughts to your purpose. How best you can contribute to this world. On the daily and in the long term. And lastly, stay learning and stay challenging your world view whilst staying true to yourself and your convictions of love. I mean, what kind of scientists would we be if we didn’t stay malleable, flexible, open to learn, discover, change?

So “To Be or To Do (Not To Be)?” A beautiful tragedy – I say both. Be you → Do you.


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