Measure Evolutionary Change Practice Test

In a population of rock pocket mice living on dark lava, scientists tracked fur-color trait frequency over 5 generations. Evolutionary change can be measured by shifts in trait frequency (the proportion of individuals with a trait) across generations.

Data (same population each generation):

• Generation 1: 20 out of 100 mice have dark fur
• Generation 2: 35 out of 100 mice have dark fur
• Generation 3: 50 out of 100 mice have dark fur
• Generation 4: 65 out of 100 mice have dark fur
• Generation 5: 80 out of 100 mice have dark fur

Which statement about evolutionary change is supported by the evidence?

A population of snails on the same shoreline has two shell patterns: banded and unbanded. Scientists recorded trait frequency for 4 generations. Evolutionary change can be measured by shifts in trait frequency across generations.

Data (out of 100 snails each generation):

• Gen 1: 70 banded, 30 unbanded
• Gen 2: 55 banded, 45 unbanded
• Gen 3: 45 banded, 55 unbanded
• Gen 4: 35 banded, 65 unbanded

Which claim about evolution is incorrect based on the data?