Which of the following are causes of the evolutionary change? Select all that apply.

Which of the following are causes of the evolutionary change? Select all that apply.

a. Gene flow

b. Genetic drift

c. Mutation

d. Natural selection

Answer: The correct options are a,b, c and d.

These are the four fundamental ways in which evolution occurs within a population. Migration transfers new alleles or genes from one population to another through the movement of organisms or reproductive cells. Genetic drift is also defined by random change of allele frequency and this mainly occurs in small population groups such as isolated islands, etc. Mutations are basic to evolutionary theories for they create new alleles which may be transmitted through the whole population. By shaping the frequency distribution of alleles in a population, natural selection promotes the increases in the frequency of beneficial alleles and the decrease in the frequency of detrimental alleles, which give impetus to adaptational evolution. As such, these mechanisms influence the genetic dynamics of the population over time, thus causing changes that may culminate in the evolution of new traits and ultimately, the evolution of a new species.