Biology District Common Assessment (Natural Selection)

Identify one pattern in the perch height data.

• With or without brown anoles, the green anoles' perch height increased.

• With or without the brown anoles, the green anoles' perch height decreased

• After the brown anoles invaded, over time, the green anoles' perch height increased.

• After the brown anoles invaded, over time, the green anoles' average perch height decreased.

When the brown anoles invaded, scientists noted that they ate similar food and lived in similar habitats as the green anoles. How do these similarities contribute to the green anoles’ population change over time? Select the TWO best answers.

• There was variation between the color of the brown and green anoles, which contributed to the anole population change over time.

• There was variation between the footpad sizes in the green anoles, which contributed to the green anole population change over time.

• Green anoles that were able to live higher in the trees were able to survive and reproduce, which contributed to the green anole population change over time.

• Brown and green anoles competed for the same food, which resulted in a decrease in the population size of the green anoles.

Why might being able to go higher in trees be an advantage for survival?

Select the TWO best answers.

Higher up in the trees, the green anoles

• experience less competition for resources.

• stay warmer.

• increase offspring survival.

• can see predators better.

Which one of the following sets of graphs best represent how you think the proportion of green anoles with larger footpads in the population changed over time on the invaded and uninvaded islands?

• 
• 
• 
• 

The scientists noted that the green anoles did adapt because of variation in footpads and sticky scales.

Which one of the following choices best describes the pattern of the average number of sticky scales and average footpad size traits of anoles on invaded and uninvaded islands?

• The anoles’ footpads are smaller and the anoles have less sticky scales on islands that were invaded by brown anoles.

• The anoles’ footpads are smaller and the anoles have more sticky scales on islands that were invaded by brown anoles.

• The anoles’ footpads are larger and the anoles have less sticky scales on islands that were invaded by brown anoles.

• The anoles’ footpads are larger and the anoles have more sticky scales on islands that were invaded by brown anoles.

Using your graphs and the data above, what explains the patterns you see between invaded and uninvaded islands?

Select the TWO best answers.

• The green anoles on the invaded islands survived if they were able to climb and perch at higher heights. They could do this because they had larger footpads and more sticky scales on their feet.

• The green anoles on the invaded islands were able to grow larger footpads and sticky scales in order to climb and perch at higher heights and survive.

• The population of green anoles did not show change over time, because the invasion of the brown anoles did not cause any changes.

• The population of green anoles that changed in order to survive reproduced at a higher rate and passed on their traits.

• The population of green anoles that survived and reproduced had a higher average footpad size and a larger number of sticky scales on their feet.

Sometimes rare diseases are introduced on islands when nonnative species are introduced. What if a rare fungal disease that only killed brown anoles was brought to an invaded island by researchers who were studying the anoles?

Using the data provided and what you know about natural selection, which one of the following predictions is most supported by evidence?

• The brown anole population size would decrease overall, because of the disease, but there would be no impact on the green anoles’ population characteristics, because there is no relationship between the two.

• The brown anole population size would decrease overall, which would result in less competition for resources for the green anoles, who would be able to survive and reproduce equally well at different perching heights. Without large footpads being selected for, there would be an increase in green anoles with normal footpads over time.

• The brown anole population size would decrease overall, which would result in less competition for resources for the green anoles, who would be able to survive and reproduce equally well at different perching heights. After one generation, the green anole population would be back to how it was before the brown anoles were introduced.

• The brown anole population would not decrease, because they would become immune to the disease and still be the stronger lizard species. This would mean that the introduction of this disease would have no impact on the green anoles’ population characteristic.

Constructed Response:

Using the information from the Anole scenario,

1. 1. Construct a scientific explanation for how natural selection led to the adaptation of the population of green anoles when the brown anoles invaded their habitats in Florida.

   3. 2. Support your claim with evidence provided in this assessment.

In your reasoning, describe how evolution occurs primarily as a result of four factors.