Question

Which statement describes an instance of speciation in gerbils?

A. Two gerbil populations become isolated, reducing the gene flow,
and over time the populations diverge genetically to a point at
which they can no longer interbreed.
B. Individuals from different gerbil populations are free to mate,
resulting in high gene flow and greater genetic variation in the
gerbils.
C. Natural selection favors certain traits in gerbil populations, and
over time the individuals with more favorable traits form new
populations.
D. Evolution produces new traits that are advantageous to one
population of gerbils, allowing them to outcompete other
populations.

Answer 1

Allopatric speciation occurs when two populations of the same species become geographically isolated, leading to genetic divergence and the formation of new species.

Step-by-step explanation:

The statement that describes an instance of speciation in gerbils is: 'Two gerbil populations become isolated, reducing the gene flow, and over time the populations diverge genetically to a point at which they can no longer interbreed.' This process is known as allopatric speciation, which occurs when a population is geographically separated into two or more isolated groups that cannot mate with one another. Due to the independent evolution of these groups, driven by different environmental pressures, natural selection, mutation, and genetic drift, they become distinct species.

For instance, if a new river forms and divides a gerbil population, the two groups will no longer be able to interbreed. Over time, as the isolated populations adapt to their own unique environments, they accumulate genetic differences. If the split persists long enough, these changes can lead to the emergence of new gerbil species that can no longer interbreed even if they come back into contact.