What can Nature teach us about stress management?
By Darja Dubravcic
"What do the ecology, the economic system, the company, the city, the organization, the cell have in common? Nothing if we examine them with the usual instrument, the analytical approach. But many, if we highlight the great organizational rules and regulations of all these systems. "
So what principles do biology and economy share? The main principle that drives both disciplines is the maximization of profit in economy or fitness in case of biological organisms. If one organism produces more offspring it will outcompete the other one. If one company has higher profit than its competitors it will expand and take over the market. The difference is in terminology we use, not in processes that are happening. Thinking in these terms we can ask how do organisms like plants, animals and even bacteria deal with stressful situations and can we learn something out of it?
Very often stress and risk is caused by decision making in imperfect environment. For example, investing into a startup without knowing how market will respond to it. How does this relate to organisms? What is a financial market to an economist, an environment is to an organism. When a desert plant seed needs to decide weather it will germinate or not it is making the same decision as an agriculturist that needs to choose the timing of wheat sowing or an economist deciding the timing for an investment. If the seed germinates but there is not enough rain in the future days the desert plant seed will die, the agriculturist will have low wheat production and economist will have low investment return. So how does one decide when uncertainty is the only reliable information?
Human strategies are mainly based on predictions. We do not know how the future market will look like, so we build complex mathematical models to predict it. But nature does not have big computers that predict future. That's why it has developed an array of strategies that deal with the change and uncertainty. The basic principle behind all of them is « you fight change with change » (2). If you are a swan it means that you will migrate to the south when its starts being too cold. If you are a chameleon you will develop the ability to change colors. If you are a tree you will make sure than your seeds do not germinate at the same time. And if you are an immune systems you will produce around 10^6 different antibodies, hoping that a least one of them will work against the pathogen. (Figure 1).
Figure 1. Nature has developed an array of strategies to fight with change and uncertainty. a) swans migrate to the south (5), b) chameleons change color of their skin (6), c) human immune systems produces 106 different antibodies in hope that one will kill the pathogen (7), d) amoebas create social groups protect them during starvation periods (8)
My PhD project focused on understanding stress management in amoeba Dictyostelium discoideum. It's an unicellular organisms that lives under the soil where it eats bacteria. When there is no food anymore, the famine period arrives. It can last 10h or 10 days, the amoebas do not know. They have therefore developed 2 strategies to overcome this deadly periods (3,4). The social strategy that is successful if the famine is long and the non social strategy that pays off if famine period is short. Since they do not know how long the famine will last one part of the population plays one strategy and the other part the other one. What they are doing is no different that betting. They invest into both strategies and hope that one will work.
Environment is a constantly changing battlefield. In order to deal with this change animals, plants, fungi and bacteria have developed strategies to deal with stress and risks. Some bet, some mutate, some cheat, some socialize. At the end is it really so different from what we do? Looking into other living systems enables us to discover other means of adaptation, their costs and benefits. And than maybe we can learn some things out of them. At the end they are the successful result of millions years long evolution.
References
Joel de Rosnay, Le macroscope - Vers une vision globale, 1975, Seul, Paris
Meyers LA and Bull JJ, 2002, Fighting change with change, TRENDS in Ecology & Evolution, Vol 17, No 12, 551-557
Kaushik S and Nanjundiah V, 2003, Evolutionary questions raised by cellular slime molds, Proc. Indian natn SciAcad., B69, No.5, 825-852
Dhaulsky G and Kessin RH, 2007, The cold war of the social amoebae, Current Biology, 17, 684-692
http://www.kwic.com/~pagodavista/schoolhouse/species/birds/migrate.htm
http://www.treknature.com/gallery/photo195625.htm
http://www.scienceclarified.com/Al-As/Antibody-and-Antigen.html#b
http://puruggananlab.bio.nyu.edu/research.php?action=research