Tuesday, March 9, 2010
"Random change in the frequency of genes over time is called genetic drift," (Coyne, 123). The line between genetic drift evolution and natural selection evolution to me seems very blurred. How can gene interactions be labeled random when the people mixing their genes to create a child may still exist because they have traits that helped them in natural selection? How can genes become "fixed" in a population to the point where there is 100 percent frequency of the gene, isn't there too much variation in the world to make that happen? What information can be found that verifies that genetic drift is a random process; that there is no possible reason that it happens? Also, genetic drift is said that it cannot cause adaptations then why is it considered evolution if evolution is a process that leads to adaptation? The book says that "What drift can do is cause the evolution of features that are neither useful or harmful to the organism," (Coyne, 123). This is saying that genetic drift does not help or hurt the organism but on the next page it contradicts itself by saying that it can "Raise the frequency of harmful genes even though selection is working in the opposite direction," (Coyne, 124). If genetic drift can raise the frequency of harmful genes than it is hurting the organism correct? Overall, what is the point of genetic drift and where is the line between genetic drift and natural selection?