Thoeries Of Evolution Essay -- essays research papers fc

Thoeries of EvolutionEvolution is the process by which living organisms originated on earthand have changed their forms to aline to the changing environment. The earliestknown fossil organisms are the single-celled forms resembling modern bacteriathey date from about 3.4 billion years ago. Evolution has resulted in in series(p) radiations of new types of organisms, many of which have becomeextinct, but some of which have developed into the present fauna and flora ofthe world (Wilson 17).Evolution has been studied for roughly two centuries. One of theearliest evolutionists was Jean Baptiste de Lamarck, who argued that thepatterns of resemblance found in various creatures arose through evolutionarymodifications of a common lineage. Naturalists had already established that diverse animals are adapted to different modes of life and environmentalconditions Lamarck believed that environmental changes evoked in individualanimals direct adaptive responses that could be passed on to their offspring asinheritable traits. This generalized hypothesis of evolution by acquiredcharacteristics was not tested scientifically during Lamarcks lifetime.A successful explanation of evolutionary processes was proposed byCharles Darwin. His most historied book, On the Origin of Species by Means ofNatural Selection (1859), is a landmark in human understanding of nature.Pointing to variability within species, Darwin observed that turn offspringinherit a resemblance to their parents, they are not identical to them. Hefurther noted that some of the differences between offspring and parents werenot collectable soley to the environment but were themselves often inheritable. Animalbreeders were often able to change the characteristics of domestic animals byselecting for reproduction those individuals with the most desirable qualities.Darwin reasoned that, in nature, individuals with qualities that do thembetter adjusted to their environments or gave them higher reproductivecapacities w ould tend to leave more offspring such individuals were said tohave higher fitness. Beca manipulation more individuals are born than survive to breed,constant winnowing of the less fit-a natural selection-should occur, leading toa population that is well adapted to the environment it inhabits. Whenenvironmental conditions change, po... ...le in the ill-consideredterm have broad tolerances, which may better enable them to survive extensivechanges. Human beings are uniquely adapted in that they make and use tools anddevices and invent and propogate procedures that give them extended control overtheir environments. Humans are significantly changing the environment itself.The effects are most complex and cannot be predicted, and yet like thelikelihood is that evolutionary patterns in the future will reflect theinfluence of the human species(Microsoft96).Works CitedArdrey, Robert. The Hunting Hypothesis A person-to-person ConclusionConcerning the Evolutionary Nature of Man. New YorkAn theneum, 1976.Encarta 96. Computer Software. Microsoft, 1995.Gribbon, John and Cherfas, Jeremy. The Monkey Puzzle Reshaping theEvolutionary Tree. Philly Pantheon, 1982.Reader, John. Missing links The Hunt for Earliest Man. Boston Little,1981Schwartz, Jeffery H. The flushed Ape Orang-Utans and Human Origins.San Francisco Houghton, 1987.Wilson, Peter J. The Domestication of the Human Species. OxfordYale, 1991.