The Food Movement, Rising | by Michael Pollan | The …
Since the most dramatic instances of speciation seem to have happened in the aftermath of mass extinctions, this essay will survey extinction first. A corollary to is that if any critical nutrient falls low enough, the nutrient deficiency will not only limit growth, but the organism will be stressed. If the nutrient level falls far enough, the organism will die. A human can generally survive between one and two months without food, ten days without water, and about three minutes without oxygen. For nearly all animals, all the food and water in the world are meaningless without oxygen. Some microbes can switch between aerobic respiration and fermentation, depending on the environment (which might be a very old talent), but complex life generally does not have that ability; nearly all aerobic complex life is oxygen dependent. The only exceptions are marine life which has adapted to . Birds can go where mammals cannot, , for instance, or being , due to their . If oxygen levels rise or fall very fast, many organisms will not be able to adapt, and will die.
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Economics is the study of humanity’s material well-being, but humans have rarely thought past their immediate economic self-interest, even when the long-term prospects were obviously suicidal, such as today’s global energy paradigm. Because environmental issues affect humanity’s material well-being, they are economic in nature. As can be seen so far in this essay, there was little awareness or seeming caring in early civilizations whether they were destroying the very foundations of their civilizations. Even if they did not care how much other life forms suffered, they did not seem to realize that it also meant that those oppressed and exterminated organisms and wrecked environments would not provide much benefit to humanity in the future, especially energy, whether it was food or wood.
As will become a familiar theme in this essay, the rise and fall of species and ecosystems is always primarily an energy issue. The Ediacaran extinction is a good example: Ediacaran fauna either an energy source for early Cambrian predators, ran out of food energy, ran out of the oxygen necessary to power their metabolisms, or lacked some other energy-delivered nutrient. After the extinction events, biomes were often cleared for new species to dominate, which were often descended from species that were marginal ecosystem members before the extinction event. They then enjoyed a of relative energy abundance as their competitors were removed via the extinction event.