Question

a population of western skinks, a type of lizard, lives in a grassland habitat along the base of a mountain range. the construction of a multi - lane highway will divide the habitat into two separate regions. how will the construction of the highway most likely affect the western skink population?
a. the western skink population size would decrease by half, reducing the probability that the population will evolve and speciate.
b. western skinks would become better able to find unrelated mates, decreasing the population’s susceptibility to diseases.
c. western skinks would become an invasive species in one of the two regions, so the total population size would increase.
d. the western skink population would be separated into two groups, and genetic diversity would decline in each group.

Explanation:

When a habitat is split by a highway, the skink population is geographically isolated into two groups. This prevents gene flow between the groups. Over time, each small, isolated group will experience a decline in genetic diversity due to genetic drift, inbreeding, and limited mating pools. Option A is incorrect because population size halving does not directly drive speciation quickly, and the probability of speciation is not tied to this simple size reduction. Option B is wrong because isolation reduces access to mates from the broader population, increasing inbreeding and disease susceptibility, not decreasing it. Option C is incorrect as the skinks are native to the area, not invasive, and habitat splitting does not make them invasive.

Answer:

D. The western skink population would be separated into two groups, and genetic diversity would decline in each group.