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?

1. The amount of available food may have increased

3. The squirrels of subsequent generations should show greater level of genetic variations than previous generations because squirrel that would not have survived in the past will now survive

Explanation:

1. The amount of available food may have increased

2. The parental generation of squirrels developed better eyesight due to improved diet; the subsequent generation inherited better eyesight

3. The squirrels of subsequent generations should show greater level of genetic variations than previous generations because squirrel that would not have survived in the past will now survive

4. This is probably a good example of natural selection

The illustration showed that a significantly larger percentage of squirrels produced in a particular generation survived compared to the previous generation. It means that there is a factor responsible for the sudden increase in the survival rate of the produced squirrels.

One of the factors that caused the previous generations to not survive much is competition for food. Hence, the availability of increased food will definitely cause more squirrels to survive.

As a result of increased in survival rates, the squirrels of subsequent generations should show more level of genetic variation when compared to the previous generation. This is because the increased in survival rate will lead to an increase in population and hence, an increase in the number of genes in the population.

Both options 1 and 3 can be deduced from the population.