Darwin And Natural Selection

7 Pages 1767 Words

ing of equal survival value compared to the parent gene structure, population fluctuations due to chance factors, geographical factors such as oceans or mountains which cause breeding isolation, gene flow, and changes in the length of reproduction and fertility periods. Each of these, separately and in combination though, are totally insufficient to account for evolution.
The best-known major rivals of the gradual evolution via natural selection model are vitalism, Lamarckism, mutationism, the neutralist’s theory (the theory of evolution by random walk) and Goldschmidt's hopeful monster theory, all of which have now been largely rejected; although occasionally books surface that defend one of these theories, especially vitalism and Lamarckism.
The major concern of evolutionists is to explain the incredible diversity in the living world. Pandas, elephants and mice are all biologically basically similar, yet manifest many differences. Even more different are the reptile, mammal, bird and insect and fish divisions. A viable theory of origins must explain this often unexplainable diversity, and the fact that literally millions of different species of animals and plants exist. The explanation that each living type was separately created by God in the creative week described by Genesis was historically accepted by most Westerners and probably most scientists as well, until the middle 1800's. Darwin believed that he had an answer w...