Charles Darwin was a man of incomprehensible genius. He proposed theories that changed the views of the origin of mankind, as well as, the beginning of life on earth and the continual evolution of advanced forms of life. Other great scientists such as Galileo and Aristotle influenced many of Darwin’s theories and statements. With the publication of Darwin’s “Origin of Species” in 1859 and the subsequent acceptance of evolution by natural selection, patterns in nature were recognized as the outcome of common descent, not divine creation. Darwin wrote to his friend and colleague Thomas Huxely: “The time will come, I believe, though I shall not live to see it, when we shall have fairly true genealogical trees (metaphor on human evolution often discussed by Darwin) of each great kingdom of nature.” Darwin’s dream remained just that, a dream but is without doubt, beginning to take tangible form, with current genetic studies.
According to Oparin’s hypothesis (hypothesis formulated about the creation of life on earth) the first simple cell, emerged about four billion years ago. How can that hypothesis be extended to explain the variety of life forms that exist on earth today? (Question formed by scholars in an attempt to stump Darwin)
“As many more individuals are produced than can possibly survive, there must be in every case, a struggle for existence, either one individual with another of the same species, or with individuals of distinct species, or with physical conditions of life. Can it be thought improbable, seeing that variations useful to man have undoubtedly occurred, that other variations useful in some way to each being in the great and complex battle of life, should sometimes occur in the course of a thousand generations?”
Darwin answered the baffling question in the form of another question and hypothesis. His response to the question of diversification complicated matters further as many more scholars came to support the theory of probable existence (life forms simply just appearing – possibly an act of God). Darwin responded to these claims against his theories with a series of hypotheses concerning differential evolution (differential evolution is the separation of cells at the beginning of life on earth creating different species from those primordial cells); Darwin’s claims were against the theory of probable existence. Darwin’s responses were regarded as too far-fetched to be true; or more simply, lies.
In nature, both plant and animal life forms adapt to their surroundings in order to survive. Adaptation is crucial to the success of a particular species. Adaptation has allowed humans to digest certain foods. Another example would be that certain species of animals grow fat prior to the winter so that the cold will not overcome them and cause them to freeze.
When Charles Darwin was twenty-two years old, perhaps the most significant event in his life took place. The year was 1851 and the young scientist was invited to become a member of an expedition to explore natural phenomena around the world. It was this trip that would produce his most significant theoretical contributions to the biological sciences. Ports of call, which included the Falkland and Galapagos Islands, were destined to change our understanding of the process of evolution. His vessel, “The Beagle”(a ketch sailboat), had been used to mount other expeditions to places around the world such as Africa and India. Captain George Peacock, a fellow scientist who took to the sea after his life’s thesis on evolution was rejected by the national science academy, invited Darwin to the vessel. Darwin’s close associate, Robert Fitzroy, accompanied him on the voyage and served as a crewmember aboard the Beagle.
Darwin derived one of his most significant theories from the Galapagos Islands. Darwin noted that several species of finches dominated the few islands he observed. As Darwin traveled from island to island he noticed that groups of birds on certain islands had evolved specialized beaks for collecting food. He observed that an entire species of the birds fed on one particular food source However, as the food source became less abundant, groups of finches turned to alternate food sources on each island. Some birds developed short heavy beaks suited to breaking open the husks of seeds. Others developed long thin beaks that were adapted to picking food from bark or crevices in rocks. With specialized beaks, the birds were able to survive in different ecological niches. As they bred with other birds in their niche, they evolved into completely different species – no longer able to interbreed with other finches. The interesting part of this phenomenon is that all the finches had been subject to the same living conditions (Climate, food source, structure, etc.).”The principal of adaptation is perfectly proven in life “(Charles Darwin).
Darwin and Glick express the principal of divergence as follows:
“The long over looked problem was “The tendency of Organic beings descended from the same stock to diverge in character as they become modified.’ The joyful solution was “That the modified off-spring of all dominant and increasing forms tend to become adapted to many and highly diversified places in the economy of nature.” The essence of this principal is that natural selection not only provides adaptation of organisms to their environment, but also selects for divergence. In other words, divergence can be adaptive under certain instances; hence there is selection in nature for ecological complexity”
(Darwin and Thomas F. Glick) “Charles Darwin on Evolution” Indianapolis, Indiana. Hackett Publishing Company, 1996: Chapter 6
Darwin’s work on the origin and evolution of all species of plants and animals can be divided into two major issues: a) to prove that modern species were revised descendants of earlier species -that species had evolved; b) to show how this process of “descent with modification” had occurred. If Darwin hadn’t had a vision of a mechanism, natural selection, by which this inconceivable historical transformation could have been accomplished, he would probably not have had the motivation to assemble all the circumstantial evidence that it had actually occurred.
Ultimately, the study of evolution, natural selection, mutation, and adaptation, is directed toward answering a basic mystery-where do we(humans) come from? Prior to Darwin’s studies, philosophers and naturalists believed in a divine scheme which directed itself toward “perfectionism” with mankind as the pinnacle of the evolutionary track; one step down from the angels which were, in turn, one step down from the divine being (God). However, it was Darwin’s theory of common descent, which left no escape from the conclusion that humans had indeed descended from ape-like ancestors ( beings most similar to us). There was nothing supernatural about the origin of Human Beings.