The sun provides a tremendous amount of energy to the Earth every day, far more than is currently used. Given this fact, why is the acquisition of energy a constant task for organisms? Why do so many creatures starve?
Well, although it is true that the Sun provides more energy to the Earth in a day than can be used in this short 24-hour period, not all organisms can turn sunlight into direct energy; this means that while there is a surplus of energy from sunlight, there may be a lack of energy available through consuming other organisms. (If there are no organisms to be consumed, the consumer may starve and die within a fairly short amount of time due to lack of energy and ability to carry out any internal process in the cells.) Organisms such as plants, for example, have chloroplasts in their cells that are able to harness the energy of light waves, and using chlorophyll they can turn this energy into carbohydrates; this process is called photosynthesis (Bear, Lesson 7). This means that, as long as they have water for basic sustenance, they are able to directly convert sunlight into energy; organisms at this level of the pyramid are referred to as producers. Animals, and humans on the other hand unfortunately do not have this ability. We must consume other plants or animals to receive energy, and when an organism is consumed only about 10% of it’s energy will be carried to the next level of the pyramid. This means that the higher up the food chain you reside, the harder it will be to obtain the amount of energy you need to survive. Humans who consume meat (in this pyramid) are referred to as tertiary (or sometimes secondary) consumers. ‘Top level carnivores’ if you will. If energy becomes scarce on even the lowest levels of the pyramid, it will negatively affect all those above it, causing starvation, sickness, or death.
Pyramid of Biomass. Digital image. Cheatography. Cheatography.com, n.d. Web. 18 Sept. 2014. <http://www.cheatography.com/wkcheezy/cheat-sheets/science-ecology-review/>.
Biology Lesson 7: Introduction to the Cell. Prod. Jacob Bear. Perf. Jacob Bear. The Ron Paul Curriculum. The Ron Paul Curriculum, 2013. Web. 18 Sept. 2014