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.

d concave shape of wave rock

explanation:

the concave shape of wave rock is a very good evidence that supports the evolution of earth due to chemical weathering. if we talk about structure of   wave rock, studies have estimated that it is around 2.7 billion years old. it also serves as the foundation of evidence that it was the place where australian continent began to form.

how the structure of wave rock was created?

studies suggest that structure of wave rock was created when the surrounded area was started to weather due to which deposition of material started on the part of land which now contains wave rock.

the structure of wave rock is considered to be one of the best-known landforms in australia. at the height of around 15 cm, there can be found flared slopes which formulate the margins of hyden rock. it is now assumed by geologists that wave rock was created by subsurface water-induced weathering and not by glaciers, waves or wind.

due to deposition of material over the period of long time, the wave rock became tougher and tougher due to weathering from surrounding terrain. this makes it a physical evidence that supports   the evolution of earth due to chemical weathering.

hope it !

answer: national resource conservation services

national resource conservation services is the us. based approach that provides technical and financial assistance for natural resource management. nrcs society in conservation of resources by involving in activities like farmland protection, flood prevention, watershed protection, urban conservation, conserves economic and environmental conditions. it conducts soil surveys and implements the policy of natural resources management on the society.