We in the biological sciences seldom turn to concepts of social sciences. However, there are many things which can be interlinked to other sciences. One such concept is what is called the tragedy of commons. Let me explain.

It is easier for me to think in small numbers. Imagine a village which has just four villagers. There is agricultural land near the village which can be cultivated to yield 8 kilograms of rice every week. The trouble is, the rice takes a week to grow, and one kilogram of rice can be grown to yield two kilograms again. In addition to this, if they eat their fill, one kilogram lasts only for a week. The villagers can't grow any other food, and they can't live on anything else. How do they share the food?

The best way to do this is for each of them to take one kilogram of rice to eat, and use the four remaining kilograms of rice to grow eight kilograms of rice again. This way, the land is always with 8 kgs of rice at the end of every week and the villagers are also well fed.

Let's say that one person becomes a little more cautious, or selfish, or anything that makes him want to take more than he needs. Let's say he just takes 500 grams more. What happens then?

At the end of the first week, they have only 3.5 kilograms left to sow, that is only 7 kilograms at the end of the second week. Now even if he doesn't take any more extras, the damage is done. If the four kilograms are taken, there will only be three kilograms left, meaning only six at the end of week three. And four at the end of week four. Zero after week five. There is a way to reverse this, of course. They can eat lesser for some time until the rice to sow comes to 4 kilograms again, but who would do it unless ask of them decide together.

This is not a realistic situation, I know that. In real life, the resource isn't only one, there are many. The input to output isn't 1:2, it is greater, fortunately. The resources used don't deplete as easily. But the number of people who take in excess is higher, and the number of times they do it is also higher, not just once.

The tragedy of commons presents a bleak picture of the consequences of gluttony and hoarding.