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Figure 1: Simple Photosynthesis
Figure 2: The Process of Making ATP
Figure 3: The Electron Transport Chain
Humans are quite a bit more than what they eat, but surely what they eat has a significant effect on their lives. All living organisms need energy to live, and that is obtained from food. It also supplies the essential building blocks of the body, enabling growth from infancy to adulthood and beyond. It is both a complex and fascinating story about how the physical features and the developmental history of humans have been shaped by what, and how early man consumed.
The time line of history is a long one, but for mankind, it is relatively short, depending on who you believe. Two million years is a good estimate, with Homo sapiens going back a million years.1 Others say it should be only about 500,000 years.2 Because man is a primate, he is a predator who looks for prey. Prey are animals that mainly eat grass and have eyes on the sides of their heads, usually with long necks and skulls to reach the ground, chopping, chewing teeth—but no canine teeth—and a very long and complex digestive system. Predators who feed on prey have short necks, powerful jaws for killing and ripping, crushing teeth and eyes that face forward. Both types of animals have acute senses of smell and hearing. Man can be both predator and prey.
Primitive man was mainly a meat eater. Small animals at first, such as bugs and mice, but as he developed, he chose larger animals. Of course, before the discovery of fire, all food was eaten raw. There were advantages and disadvantages to this practice. The upside was that he needed no supplements; all the vitamins and minerals were supplied courtesy of his victim. The downside was the meat did not last long because it decayed quickly and contained bacteria, parasites and heaven only knows what else. Primitive man also ate grass, tubers, nuts and berries. His digestive tract most likely could not handle uncooked grains, but the advent of fire solved that problem.
Approximately 40,000–50,000 years ago, a few smart early people noticed that if they put seeds into the ground, they no longer needed to go gather seeds far from home. Farming started as a primitive practice, but rapidly grew during the next 20,000–30,000 years. Animals were domesticated and houses were built, first as crude huts, but later as more elaborate dwellings. Society was born—all that was lacking was the invention of politics, which surely came with early civilization. Notice the flow of time and the decreased need for maximum effort on the part of mankind. With abundant food, clothing and shelter, life changed and with it, so did man’s need to adapt to a new lifestyle.
Mankind originally may have roasted food, and later used a boiling technique.Possibly the net result of plentiful cooked food was the onset of arterial disease and associated obesity. The human diet today includes overeating and many junk foods. Because of this, metabolic diseases have hit humans pretty hard, especially cancer and atherosclerosis, which is often linked to diabetesa.