Evolution (Evolution)

by whitecraw, Sunday, March 30, 2008, 20:13 (5869 days ago) @ David Turell

Randomness is certainly a factor in evolution, but there are also non-random evolutionary mechanisms. Random mutation is the ultimate source of genetic variation in nature (as opposed to the laboratory). However natural selection, the process by which some variants survive and others do not, is not random but is determined by the environment in which the competition among individuals to survive and reproduce takes place. - For example, individuals within populations of some aquatic animals are more likely to survive and reproduce if they can move more quickly than their fellows through water. Speed helps them to capture prey and to escape danger. Given this situation, individuals with more streamlined bodies are more likely to survive and reproduce than those with less streamlined bodies. Individuals that survive and reproduce better in their environment will tend to have more offspring (displaying the same traits) in the next generation. Natural selection, unlike mutations in DNA sequences, which occur entirely by accident in nature and according to no rule or method but entirely by mistake, is thus a non-random process. To say that evolution happens 'by chance' ignores half the picture.