Question

If the original finches that had been blown over to the Galápagos from South America had already been genetically different from the parental population of South American finches, even before adapting to the Galápagos, this would have been an example of

A) genetic drift.
B) bottleneck effect.
C) founder effect.
D) all three of these.
E) both the first and third of these.

Answer 1

The correct answer to the question is C) founder effect, which occurs when a new population is established by a subset of the original population, carrying with it an unrepresentative set of alleles. Genetic drift includes both the bottleneck and founder effects, but they occur under different conditions. The scenario described is not a bottleneck event but rather represents the founder effect.

Step-by-step explanation:

If the original finches that had been blown over to the Galápagos from South America had already been genetically different from the parental population of South American finches, even before adapting to the Galápagos, this would have been an example of the founder effect. The founder effect is a form of genetic drift where a few individuals establish a new population that is not genetically representative of the original population. Since this scenario involves a new population being established by a subset of the original population and carrying with it an unrepresentative set of alleles, it matches the definition of the founder effect.

Genetic drift is the effect of chance on a population's gene pool and it can manifest in special cases such as the bottleneck effect and the founder effect. The bottleneck effect occurs when a population's size is significantly reduced due to a catastrophic event, leading to a random alteration in allele frequencies that is not based on the organisms' traits. However, since the finches in question were not subjected to a catastrophe that reduced their numbers, but rather were part of a group that started a new population, the bottleneck effect is not applicable in this case.

Therefore, option C, the founder effect, is the accurate answer. It is important to note that while both bottleneck and founder effects are examples of genetic drift, they occur under different conditions and are not interchangeable terms. The correct answer is C) founder effect.

Answer 2

If the original finches that had been blown over to the Galápagos from South America had already been genetically different from the parental population of South American finches, even before adapting to the Galápagos, this would have been an example of

E) both the first and third of these.

Step-by-step explanation:

Genetic drift was the process of changing of allele frequencies over generations in a random fashion.

Founder effect is closely linked with the genetic drift. In this case, a few individuals of the original population start a new colony isolated from the other members of the species.

A founder effect happens when a new colony started from few members of the original population. The small size of population means that the colony may have a small variation of the genes in the original population.

A founder effect event happens when a small group of individuals was separated from the rest of the population, whereas a bottleneck effect occurs when most of the population is destroyed.