Threads Of Life :: essays research papers

Thread of flavourThis book covers the patterns of evolution and how each species and time era had an effect on Earths history. It covers the world from the beginning to the present times telling us all that has happened in between. The book begins by introducing us to geology and how it is utilise in telling time and finding fossils. The Grand canyon is a good place to begin because it is the worlds greatest geological gash. Sediment was deposited here layer upon layer and eventually the layers were cut through by the atomic number 27 River. The time covered by the layers of rock in the Grand Canyon represent about two billion years of earths history. The next chapter introduces to us how life began. Many scientists believe that life began as soon as the earth cooled sufficiently after just forming. It is believed that the first life on earth emerged some four billion years ago. The author goes on to say that the beginning of life can be organized into cardinal stages first, t he earth forms from materials in our solar system second, chemicals such as sugars, phosphates, and aminic acids are formed third, these building blocks link together to form nucleic acids, proteins, carbohydrates, and fats fourth, these plication into proto-organisms and last, these organisms gain the ability to replicate.This explains how life begins.Soon the organisms of the water begin to uprise legs and lungs and start to venture out of the water onto the land. This brings about the era of the dinosaurs. Dinosaurs command the earth for about 185 million years and then their macrocosms began to decline. About 65 million years ago there is evidence that an asteroid afflicted the earth and caused the extinction of many species of marine plankton. The last of the dying dinosaur population may have died out before this.After the dinosaurs died off, then came the manage of the mammals. Mammals were more equipped for survival because of more intelligence and the development of a lower jaw comprised of one bone. Upper and lower molars helped mammals survive better. Mammals would besides stay with there young and nurture them until they were fit to fend for themselves. Mammals were able to survive a very long time and are unsounded evolving in present times. In the present, there is evidence that our human ancestors walked arouse some 3.75 million years ago.