Final answer:
Evolution consists of b.changes in allele frequencies within a population, driven by mechanisms such as genetic drift, gene flow, and natural selection.
Step-by-step explanation:
The unit upon which evolution consists is b) Changes in allele frequencies. This concept is fundamental in the study of population genetics, where evolution is defined as the change in the frequency of an allele within a population. For instance, using the ABO blood type system, if the frequency of the IA allele in a population shifts, this indicates evolutionary change. Factors such as genetic drift, gene flow, mutations, and natural selection can all cause allele frequencies to change, thereby driving the evolutionary process.
In biology, evolution consists of changes in allele frequencies. Allele frequency refers to the proportion of a specific allele within a population, relative to all other alleles of that gene present in the population. For example, in the ABO blood type system, the frequency of the IA allele would be the number of copies of that allele divided by all the copies of the ABO gene in the population. A change in allele frequencies over time indicates evolution in the population.