consist of body plans, which scientists have used to classify all life forms, and all significant animal phyla had appeared by the Cambrian Period’s end. The Cambrian Explosion has been difficult to explain and there is still great controversy and many unanswered questions, and it has also been difficult to explain why significant change stopped the explosion. Once the basic body plans appeared and biomes were filled, new plans never appeared again. Why did all fundamental change stop? The emerging view is the same for why complex life with and never changed since then. Not only could innovation confer great benefits, but , further travel along the developmental path made it continually less feasible to backtrack, start over, and take another path, or choose a fundamentally different path. The history of life’s choices was reflected in organisms in several ways, and the source of that inertia began to be understood when biology and chemistry at the cellular and subcellular levels were investigated, particularly after DNA was sequenced and studied. The fact that have not significantly changed in several hundred million years points to the issue. Hox genes have not changed because they control key developmental steps in embryonic development. Not only do Hox genes work, there are no practical ways to significantly change them, as they lay the animal’s structural foundation. Hox genes are called regulatory genes, and the nature of seems to be why animals have not fundamentally changed since the Cambrian Explosion.
In a striking similarity to the of evolutionary innovations, many human traits are vestiges of our history but have yet to disappear, but various social managers have used them to exploit the masses. For instance, the has a and developed because those were the most energy-rich foods that existed. But the incredibly high sugar and fat content of processed food vended by Western agribusiness companies plays to those biological proclivities in the name of profit. Diets based on such foods are disastrous for human health, and industrialized peoples, led by the USA, are the . Similarly, in-group "loyalty" (to fight the out-group) is a that arose to ensure survival. Ever since the , a goal of social managers has been forming that in-group cohesion to battle the out-group. There is not much sentient about it. As the and have made clear, people can be arbitrarily split along almost any lines and form an in-group and out-group, and the out-group will then be treated terribly. Darwin's "from the war of nature" comes "higher animals" conclusion in his is mirrored in the work of Marx and Hitler, in that they believed that human "progress" was produced by one social group violently prevailing over another. Hitler avidly read Marx, and may be how he received his "revolutionary" ideas.
Human biology research paper topics - CRESS SP
Imagine a family having a custom home built and, after it was built, they decided that they wanted a basement, four extra stories, central gas heating rather than baseboard electric heating, and a swimming pool on the third floor. It would not be feasible to renovate the home to give it those new features, especially if the family was already living in it. They would need to build a new house from scratch, with a new foundation, and they would have to find a temporary home during the construction period. But an animal has to live in its body all the time. There is no way to redesign and rebuild an animal’s foundation while it lives in its body, and the biological superstructure built on the foundation was designed for foundation. A new superstructure would also have to be designed and built on the new foundation. A six-chambered heart, for instance, could not just be invented and put into a human chest and work, or a second brain, or a third arm. The kinds of changes that feasible have to adhere to the basic structural and biochemical foundations that the phyla represent.