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AP Biology 7.6: Evidence of Evolution

Practise AP Biology 7.6 questions by evaluating statistical, fossil, geological, morphological, DNA and protein evidence for evolutionary change.

Syllabus
Effective Fall 2025
Course
AP Biology

Exam points

  • identify geological, fossil, morphological, biochemical and statistical evidence relevant to evolution
  • use rock layers, extinction markers, homologous structures and transitional fossils to infer change over time
  • compare DNA and conserved-protein sequences to infer relatedness and common ancestry
  • calculate molecular divergence rates and evaluate evolutionary hypotheses with quantitative evidence

Covered syllabus points

7.6.A—Describe the types of data that provide evidence for evolution7.6.B—Explain how morphological, biochemical, and geological data provide evidence that organisms have changed over time

7.6 Evidence of Evolution question 1

[Maximum number: 1]

Questions 14-17
Stickleback fish are found in both marine and freshwater habitats. The marine fish have no scales but have
hardened, armorlike plates along their sides. The plates are thought to protect sticklebacks from certain predators.
In the late 1980s, sticklebacks from a marine population colonized Loberg Lake, a freshwater lake in Alaska.
Starting in 1990, researchers sampled fish from the lake every four years and recorded the armor-plate phenotypes of
the male sticklebacks in each sample. The armor-plate phenotypes were categorized as either complete (plates
extending from head to tail), partial (plates extending from head to abdomen), or low (a few plates near the head
only). The results are shown in the table below.

ARMOR-PLATE VARIATION IN THE STICKLEBACK POPULATION OF LOBERG LAKE

ARMOR-PLATE VARIATION IN THE STICKLEBACK POPULATION OF LOBERG LAKE

To evaluate the reliability of the results, it would
be best to know which of the following?

A

The surface area of Loberg Lake

B

The number of males in each sample

C

The average daily temperature of
Loberg Lake

D

The age of the sticklebacks in each sample

7.6 Evidence of Evolution question 2

[Maximum number: 1]

Scientists are interested in determining the evolution of seven lizard species found on different islands of the Canary Island group. They isolated DNA from individuals of each species and sequenced the mitochondrial gene that encodes cytochrome b. The numbers of genetic differences between species are shown in the table below.

Table for Question 7.6 Evidence of Evolution question 2 — AP Biology

Based on the data in the table, which of the following lizard species are most closely related?

Figure 1. A model of an endocrine signaling pathway showing involved body parts and hormones. GnRH = gonadotropin-releasing hormone, LH = luteinizing hormone, and FSH = follicle-stimulating hormone.

Figure 1. A model of an endocrine signaling pathway showing involved body parts and hormones. GnRH = gonadotropin-releasing hormone, LH = luteinizing hormone, and FSH = follicle-stimulating hormone.

A

Species C and species B

B

Species E and species D

C

Species F and species B

D

Species G and species A

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