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... t species and that they were native to the islands but to neither of the American continents. After Darwin received these reports, his doubts about the species turned into a belief in transmutation. In March 1837 he wrote in his notebook that species changed from one place to another or from one age to the next. He continued analyzing his data, searching for a system for this process. Darwin in his Autobiography remembered his realization that given the struggle for existence everywhere, "favorable variations would tend to be preserved, and unfavorable ones to be destroyed. " The result of this would be the formation of new species.
This is how he came to the principle of natural selection. Darwin saw competition between individuals of a single species. He recognized that within a local population the individual with, the sharper beak, the longer horn, or the brighter feather might have a better chance to survive and reproduce than other individuals. If useful traits were passed on to new generations, they would eventually be predominant in future populations. Darwin changed the focus of evolutionary study from between to within species. He saw natural selection as the system by which advantageous variations passed on to succeeding generations and by which the traits of individuals that were less competitive gradually disappeared from populations.
After he discovered natural selection, Darwin then had to verify it, he made various inquires to plant and animal breeders. He hoped to learn from their experience with artificial selection to how natural selection worked. He had discovered during his voyage, different species appeared on different landmasses. Darwin solved this question of geographic distribution by assigning the spreading of populations of ocean islands to the power of wind and water. The theory of the evolution of species thus solved many questions in relative anatomy and paleontology. The idea of organic evolution was not new.
It had been suggested a generation earlier by Erasmus Darwin and by various other naturalists. But none of these earlier naturalists had presented either a system or evidence for the process. Though lack of an apparent system of inheritance eventually encouraged him to accept the latter idea, Darwin's theory was fixed in direct observation and an attempt to discover universal laws. Darwin rejected the popular view that organisms are perfectly adapted to their environment. He viewed the natural world as caught in a constant struggle between competing individuals that have different degrees of fitness. Others had seen struggles but always between species, never within them.
He recognized that it is the competition within a species leading to the survival of individuals with advantageous traits that eventually brings about the evolution of a new species. By 1842 Darwin was sure enough in his theory to write a short rough copy. Then in 1844 he wrote a longer version, which he showed to his friend, the botanist Joseph Dalton Hooker. Cautious of presenting his theory to the public, Darwin spent the next decade concentrating on a paper on barnacles.
During this time the intellectual environment in England changed and discussions about evolution became ordinary. Darwin still withheld publishing his theory. But he waited to long because on June 18, 1858, Alfred Russell Wallace, published a paper that summarized the theory that Darwin had been working on for 20 years. Darwin then began work on a summary of the larger document that he had begun two years earlier. This paper, On the Origin of Species by Means of Natural Selection, or The Preservation of Favored Races in the Struggle for Life, was published on Nov. 24, 1859.
The first edition sold out immediately, and by 1872 the work had run through six editions. The theory was accepted in most scientific circles, with the exception of a few holdouts. After the publication of the Origin, Darwin continued to write. While friends, defended the theory before the public. Darwin completed the clarification of his theory in his next three books, which all added on to of the Origin. Darwin discussed human evolution in The Descent of Man, and Selection in Relation to Sex, in which he detailed the controversial subject.
He expanded the range of evolution to include moral and spiritual as well as physical traits and indicated man's psychological as well as physiological similarities to the great apes. The second half of the book elaborated upon the theory of sexual selection. Darwin observed that in some species males battle other males for access to certain females. But in other species, such as peacocks, there is a system in which the females select males according to such traits as strength. Although most scientists rejected Darwin's description of female choice at the time, he defended this view until the end of his life. While not unanimously accepted today, the theory of female choice has many supporters among evolutionary biologists.
The last of Darwin's sequels to the Origin, The Expression of the Emotions in Man and Animals (1872), was an attempt to remove the last barrier supposed to exist between human and nonhuman animals. The idea that the expressions of such feelings as suffering, anxiety, grief, despair, joy, love, devotion, hatred, and anger are unique to human beings. Darwin linked studies of facial muscles and the release of sounds with the matching emotional states in man and then argued that the same facial movements and sounds in nonhuman animals express similar emotional states. This book laid the base for the study of ethnology, neurobiology, and communication theory in psychology.
Throughout his life his interests changed over the years from geology to zoology to botany. In his later works he included hypothetical analysis, while in his earlier works had contained mostly data. In explaining the interdependence of bees and orchids, Darwin noted that flowers that are pollinated by the wind have little color, while those that need to attract insects have brightly colored petals and sweet-smelling nectarines. He continued experiments for another 12 years on 57 species and described his results in The Effects of Cross and Self Fertilization in the Vegetable Kingdom (1876). Here he developed the idea that there are genetic advantages in having two sexes in both the plant and animal kingdoms.
To ensure cross-fertilization, which, as he knew from experiments, produced healthier, stronger offspring. Darwin worked alone at home, leading the life of an independent scientist. Money from his father made it unnecessary for Charles to seek employment. After his return from the voyage Darwin knew he would never become a clergyman like his mentor, Henslow. He proposed to his first cousin Emma Wedgwood, which he married on Jan. 29, 1839. She brought fortune, devotion, and considerable skills that allowed him to work for the next 40 years.
Newly married, the Darwin's moved into a house in London, but within a few years Darwin's increasingly poor health made them to move to the country. In 1842 the Darwin's moved into a house in the village of Downe, Kent, only 16 miles from London. Charles and Emma Darwin had 10 children; two died in infancy and a third, Anne, died at age 10. The surviving five sons went away to school.
George, Francis, and Horace became distinguished scientists, and Leonard, a major in the royal army, was an engineer. William Erasmus was not noteworthy, as were his sisters, who prepared at home to follow their mother into marriage. Henrietta married while Elizabeth remained single. Darwin was devoted to his wife and daughters but treated them as children. Over the course of his life he made important contributions to biology and many of his theories are still strongly supported even today.
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Research essay sample on The Life Of Charles Darwin