Question

According to fossil records and recent published observations, two species of leaf-eating beetles (species A and B) have existed on an isolated Island in the Pacific Ocean for over 100, 000 years. In 1964 a third species of leaf eating beetle (species ) was accidentally introduced on the island. The population size of each species has been regularly monitored. What is the independent variable in this experiment?

A. Patient A has diabetes because the patient's initial blood sugar levels dropped over time.
B. Patients has diabetes because the patient's initial blood sugar levels increased over time.
C. Patient A has diabetes because the patient's initial blood sugar levels increased over time.
D. Patients B has diabetes because the patient's initial blood sugar levels decreased over time.

Answer 1

The correct independent variable in this experiment is the accidental introduction of a third species of leaf-eating beetle (species C) to the isolated island in the Pacific Ocean in 1964.

Step-by-step explanation:

The independent variable is the factor intentionally manipulated in an experiment to observe its effect on the dependent variable. In this case, the accidental introduction of species C in 1964 is the independent variable because it was not controlled by the researchers but has the potential to influence the population dynamics of leaf-eating beetles on the isolated island.

The dependent variable, in this case, would be the population sizes of species A, B, and C, which are monitored over time. The accidental introduction of a new species serves as a natural experiment, allowing scientists to observe how the presence of species C affects the established populations of species A and B. The identification of the independent variable is crucial for understanding the causal relationship and potential ecological impacts of the introduction of a new species on the island.

Answer 2

The independent variable in this experiment is the introduction of the third species of leaf-eating beetle (species C) to the isolated island.

Step-by-step explanation:

The introduction of the third species of leaf-eating beetle (species C) in 1964 represents the independent variable in this experiment.

In scientific experiments, the independent variable is the factor that is deliberately manipulated or introduced to observe its effect on the dependent variable.

In this case, the population dynamics of the leaf-eating beetles (species A, B, and C) are being studied, and the deliberate introduction of species C is the independent variable.

This intentional introduction allows researchers to observe and measure the impact of the new species on the existing ecosystem and the populations of species A and B.

The monitoring of population sizes over time serves as the dependent variable, as it depends on the introduced species C.

The independent variable, being the introduced species, is the causal factor that may influence changes in the population sizes of the existing species on the isolated island.

In summary, the correct answer is the introduction of the third species of leaf-eating beetle (species C) as the independent variable in this experiment.