The Polar Bear (Ursus maritimus) is a bear native largely within the Arctic Circle encircling the Arctic Ocean, its surrounding seas and land masses. Although it is closely related to the Brown Bear, it has evolved to occupy a narrower ecological forte, with many body characteristics adapted for cold temperatures, for moving across snow, ice, and open water, and for hunting the seals which make up most of its diet. Though there are many theories surrounding evolution, the two stand outstanding hypotheses applying to the modification from Brown Bear to Polar Bear are Lamarck’s theory of Use and Disuse, and Darwin’s theory of Natural Selection. The intention of this paper is to compare these thesis and determine the most appropriate in relation this event.
According to Lamarck’s theory, features can be strengthened or rid of completely through use or disuse over generations. For example, Jean Baptise Lamarck believed that the giraffe's long neck was an "acquired characteristic". After a lifetime of straining to reach up to eat leaves, a giraffe’s neck would elongate. Baptise thought that the offspring of these giraffes would then be born with longer necks. Lamarck’s theory has widely been disproved, especially with the discovery of heredity genetics. If the theory were correct, a man who works hard to get large muscles, would father naturally strong children. Though the physical side of the idea may be dismissed, many researchers are studying whether behavioural traits can be passed down from a parent to their young.
Charles Darwin’s theory of Natural Selection is the process by which biological traits become either more or less regular in a species and is a key component of evolution. Natural Selection occurs when a subject has a feature that enables to be able to survive more easily than those without it. Take for example the Galapagos Finches (Darwin’s Finches). Found on the Galapagos Islands in the Pacific Ocean are a group of about 13 types of finches...
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