Question

A biologist studied a population of squirrels for 15 years. During that time, the population was never fewer than 30 squirrels and never more than 45. Her data showed that over half of the squirrels born did not survive to reproduce, because of both competition for food and predation. In a single generation, 90% of the squirrels that were born lived to reproduce, and the population increased to 80. Which inference(s) about this population might be true?A) The amount of available food may have increased.B) The parental generation of squirrels developed better eyesight due to improved diet; the subsequent squirrel generation inherited better eyesight.C) The squirrels of subsequent generations should show greater levels of genetic variation than previous generations, because squirrels that would not have survived in the past will now survive.D) Three of the statements above are correct.E) Two of the statements above are correct.

Answer 1

Given the increase in squirrel population, it's reasonable to infer that the amount of available food might have increased (A), whereas the inheritance of improved eyesight due to diet (B) is incorrect, and the genetic variation (C) cannot be assured based on a single generation's data.

Step-by-step explanation:

To infer about the population change in squirrels due to genetic variation, environmental resources, and predation, we must analyze the biological concepts that apply to the scenario described. First, let's address the inferences one by one:

• A) The amount of available food may have increased. - If more offspring are surviving, it could indicate that there has been an increase in resources such as food, which reduces the competition and allows more squirrels to reach reproductive age.
• B) The parental generation of squirrels developed better eyesight due to improved diet; the subsequent squirrel generation inherited better eyesight. - This inference suggests a Lamarckian view of evolution, which is not supported by modern genetics. Traits acquired during one's lifetime are not inherited by offspring.
• C) The squirrels of subsequent generations should show greater levels of genetic variation than previous generations, because squirrels that would not have survived in the past will now survive. - This is possible if more offspring are surviving to reproduce, but this single change in one generation does not guarantee a long-term increase in genetic diversity.
• E) Two of the statements above are correct. - Statement A seems plausible, but B is incorrect, so option E is not valid.

Therefore, we can choose the correct option, which in this case would be A, as it is reasonable to assume that better survival rates could be due to increased food availability, influencing the population dynamics. However, this doesn't necessarily lead to the conclusion that future squirrel generations will exhibit greater genetic variation (C), nor does it support the notion that improved diet provides heritable better eyesight (B).

Answer 2

The correct answer is option E, that is, two of the above statements are true.

Step-by-step explanation:

In the given case of squirrels, the population would have generally increased due to a reduction in the number of predators, or production of variants among the progenies because of recombination, and also due to increased food availability.

The events of recombination might have led to the generation of characters that are better suited for survival. Thus, of the given statements the correct statements are A and C.