Why can't food chains go on forever?
1 Answer
They must have a "start" point - the lowest organisms - and the laws of energy mean that the "chain" must really be a "pyramid", with a very small peak.
Explanation:
The Second Law of Thermodynamics says that entropy (disorder) is always increasing. So, the "peak" cannot continue on forever, nor can it get "taller" without an increase in the whole pyramid size - again, limited by the available energy.
A “food chain” is the mechanism by which higher-ordered organisms are developed and sustained by the production of more disorder – the decomposition/digestion of other organisms.
The “Chain” starts with the lowest organism forms – but may be extended in the energy sense to the solar energy received – to the highest organic forms in humans and animals.
The chain currently has “ends” because simple plant life is as close to the original energy as an organism can get, and so far there aren’t any consumers at a “higher” level than humans.
Even theoretically, the chain cannot go on forever because each higher level requires increasing the disorder in the lower level by orders of magnitude. Very soon, the total available energy in the universe would have reached maximum entropy, and it would end.
