2. A new predator arrived that preferred birds with medium-length talls. A
population of a certain species of birds based on their tail length. Initially, most of the birds had
medium-length tails, but tail lengths ranged within the species from short to long. Two years
later, the study was performed again on the same species of birds. An illustration of the birds
with different tail lengths and graphs of the data are shown below.
Number of Birds
Initial Data
Tail Length
Number of Birds
Data Collected 2 Years After
Initial Study
Tail Length
Based on the above data, what inference
can most likely be made about this
species of birds over the 2 year period
between studies?
A. A new predator arrived that preferred
birds with medium-length tails.
B. Birds with long-length tails did not have
the genetic variation to survive.
C. A disease afflicted the birds causing
the birds with short-length tails to die out.
D. An evolutionary change occurred
where birds with short-length and
medium-length tails grew long-length tails.
4.
ar
ill
C