Log In | Register

Item SP002002: If individuals from two populations of birds (Meadowlarks) cannot reproduce with each other, that is evidence that they are two different species.

Meadowlarks are small birds that live across North America. Scientists studying these birds have identified two types of Meadowlarks that look alike but make different songs. They want to find out if these two types of Meadowlarks are different species. Which of the following is the most convincing evidence that the two types are actually different species?

  1. One type eats berries and the other type eats seeds.
  2. The two types cannot reproduce with each other.
  3. Genetic tests show that the two types have a common ancestor.
  4. One type lives mostly in eastern North America and the other type lives mostly in western North America.

Pre-Test

Distribution of responses (prior to studying evolution in high school)
Answer Choice
Overall
Grades
Gender
Primary Language
 
n = 558
6–8
n = 25
9–12
n = 498
Male
n = 243
Female
n = 274
English
n = 502
Other
n = 19
A. One type eats berries and the other type eats seeds. 11% 4% 12% 12% 11% 11% 11%
B. The two types cannot reproduce with each other. 51% 40% 51% 51% 52% 51% 53%
C. Genetic tests show that the two types have a common ancestor. 20% 24% 20% 21% 19% 20% 26%
D. One type lives mostly in eastern North America and the other type lives mostly in western North America. 17% 32% 17% 15% 18% 18% 11%

Post-Test (Control)

Distribution of responses (following typical high school instruction on evolution)
Answer Choice
Overall
Grades
Gender
Primary Language
 
n = 294
6–8
n = 23
9–12
n = 247
Male
n = 109
Female
n = 171
English
n = 264
Other
n = 9
A. One type eats berries and the other type eats seeds. 8% 9% 9% 8% 8% 8% 22%
B. The two types cannot reproduce with each other. 67% 78% 65% 69% 66% 67% 56%
C. Genetic tests show that the two types have a common ancestor. 15% 9% 15% 14% 16% 15% 11%
D. One type lives mostly in eastern North America and the other type lives mostly in western North America. 10% 4% 11% 9% 11% 10% 11%

Post-Test (Treatment)

Distribution of responses (following completion of an evolution curriculum module)
Answer Choice
Overall
Grades
Gender
Primary Language
 
n = 281
6–8
n = 3
9–12
n = 257
Male
n = 132
Female
n = 140
English
n = 254
Other
n = 11
A. One type eats berries and the other type eats seeds. 7% 0% 6% 8% 5% 6% 0%
B. The two types cannot reproduce with each other. 77% 67% 78% 72% 81% 78% 82%
C. Genetic tests show that the two types have a common ancestor. 8% 0% 8% 9% 8% 8% 0%
D. One type lives mostly in eastern North America and the other type lives mostly in western North America. 8% 33% 8% 11% 6% 7% 18%