ANSWER: (E) All OF THE ABOVE
EXPLANATION:
Change in the Allele frequencies of a population is called EVOLUTION. This change in the Allele frequencies can be caused by the following evolutionary mechanism:
A. NATURAL SELECTION;
B. GENETIC DRIFT;
C. MUTATIONS IN THE GENE POOL; and
D. FOUNDER EFFECT.
NATURAL SELECTION occurs when one allele or sometimes the combination of alleles of different genes, makes an organism less or more fit, which is then able to survive and reproduce in a particular environment. However, If there is reduction in the fitness of an allele, its frequency tends to drop/reduce from one generation to the next generation.
GENETIC DRIFT refers to the change in allele frequencies in a population from generation to generation which is a direct result of sampling error or chance events. The sampling error ensues during the process of selecting the alleles for from the gene pool of the present generation for the next generation. However, this evolutionary mechanism occurs in populations of all sizes, but posses a stronger effects in populations of small size.
MUTATION is a change in the DNA (genetic sequence) in an organism at a particular locus. Mutation are often environmentally induced. Mutation can change allele frequencies and also capable of introducing new alleles.
FOUNDER EFFECT is seen when a small group of organisms or individuals breaks off from a larger population to establish a new colony. However, the newly established colony is isolated from the parent (original) population, and the individuals creating this new colony may not carry the full genetic diversity of the parent population.
Answer:
E. All of the above.
Explanation:
Natural selection is a process in which individuals with certain characteristics that makes them better fitted to survive in an environment become selected for and reproduce those changes in subsequent generations, which become more established than those individuals with characteristics that do not make them better adapted to the environment.
Genetic drift, by definition, is a change in the allele frequencies of a population over time due to evolutionary forces that selects individuals by chance. Founder effect, for example, is a factor that can increase the genetic drift in a population. Founder effect occurs when a new colony is established by a small number of a population that have come isolated from their original large population, and as a result of this, genetic variation is lost over time, as this new sub population becomes quite different from the original population.
Mutations in the gene pool of a population, is another evolutionary force that causes a change in allele frequencies as new alleles are introduced, or some alleles are taken away from a population.
Allele frequency, which refers to how common an allele of a trait is in a population, can be changed by natural selection, genetic drift, mutation, and also founder effect.
