#8/15 What is food?
How does planet Earth work?
Food is a container for the energy we eat. In a food pyramid, animals are arranged by size and the amount of energy they eat.
At the base, are plants that extract the Sun’s energy in the process we call ‘photosynthesis’. This creates a surplus of waste energy that is rich carbon molecules which we call ‘nutrients’. It’s a small fraction but still enough to collapse the world’s ecosystems.
Herbivores like caterpillars and worms evolved to eat this surplus and emit their own. Birds evolved to eat their surplus and so on. By the time you get to top predators, almost all the waste energy is consumed. That is why there are few carnivores and many more small animals.
Once balanced, there is little waste energy left and ecosystems become steady. The structure is stable enough, as long as there are both big and small animals in the right proportions.
Humans live about half way up the pyramid, so to survive, we need to be surrounded by lots of creatures similar to us.
Plants and bacteria don’t mind if we go extinct. Past mass extinctions teach us it can crumble to the base and they will rebuild from there.
By understanding the need for diversity and structure, we begin to see where humans fit in. To exist, we need to be surrounded by other animals.
