In a perfect world, everything would be in balance and each member of the food chain would be happily supplied with enough food from the group below and so forth. But it’s not a perfect world.
From a young age, we are presented with the image of the food chain : a nice, clear diagram depicting who eats whom and pictorially describing ecological cycles such as photosynthesis.
Traditionally, humans have always been at the top of the list, followed by larger carnivores, herbivores and flora. More recent versions show the sun at the top feeding producers (green plants), which in turn feed consumers (humans and animals), who then feed decomposers (bacteria and fungi).
From either viewpoint, history has shown that a change in the size of one population impacts other populations. All it takes is the depletion or expansion of one member of the food chain for the entire system to be affected.
For example, when the coyote population grows, populations of prey, such as prairie dogs, decrease. Fewer prairie dogs mean less food for coyotes, so their numbers stop increasing. Eventually a kind of balance is reached.
Similarly, healthy oceans need a balance of sharks, fish and plankton. The populations keep one another in check, neither too large nor too small to break the chain.
On the other hand, the complete extinction of numerous species within a group—say, a large majority of the herbivore population—has the potential to cause the extinction, due to lack of food, of other predatory groups.
This is especially worrisome when it comes to humans.
With a world population now over 7 billion, humans are the group most likely to wipe out one or more branches of the food web. We’ve already hunted certain species to extinction, such as Moas, Do-dos, several species of whales and birds. Many others are endangered .
As an apex predator, humans have the responsibility to make sure that other apex predators (sharks, bears, big cats, etc.) do not run out of their own resources.
In a perfect world, every species would have a constantly replenishing food supply but, alas, this is not the case. Only by balancing our consumption of food resources can we hope to preserve the natural order and make sure the chain does not break. It is within our power to be the chain’s strongest link, not its weakest.
As the Dalai Lama has said, “It is essential that we re-examine ethically what we have inherited, what we are responsible for, and what we will pass on to coming generations.”
Alfablue, February 2013