Microevolution is a change in gene frequency within a population. Though it does not create new species. This variation is due to 3 different processes which are mutations, natural selection, and genetic drift. Mutations are random changes in the composition or number of DNA molecules in a cell. Mutations occur due to inherent reasons, such as replication errors in DNA. Mutations are completely random and do not occur because they help an organism's ability to adapt to to its environment. Cases where mutations do help are rare, and such mutations are known as adaptations. Genetic drift occurs when a group of organisms within a population, happens to have a higher frequency of an allele than the surrounding organisms. Slowly the group starts to drift away from the gene pool of the main population by selectively mating within this group. In many ways, genetic drift is pretty much the same as nonrandom mating. Natural Selection determines the chances of survival for an organism and its reproductive capability. This process works with mutations to determine which organisms survive and pass their traits to their offspring.
No comments:
Post a Comment