Science Assessment

A class of students is visiting the primate room of a natural history museum. Some of the students are looking at the skeleton of a chimpanzee next to the skeleton of a gorilla.

 A sign next to the skeletons reads:

“Do chimpanzees and gorillas share a common ancestor?”

The teacher asks the students to think about that question and then to write an argument to justify their answer. This is what one of the students writes:

Common ancestors are a topic in evolution. Similar skeletal features likely indicate a common ancestor.  Chimpanzees and gorillas have similar anatomical features. For example, chimpanzees and gorillas both have opposable thumbs and their ribcages are very similar. Chimpanzees and gorillas may have a common ancestor.

Identify the claim, evidence, and reasoning statement in the student’s argument.

1. Claim: Similar skeletal features likely indicate a common ancestor.

   Evidence: Chimpanzees and gorillas both have opposable thumbs and similar ribcages.

   Reasoning: Chimpanzees and gorillas have similar skeletal features.

2. Claim: Similar skeletal features likely indicate a common ancestor.

   Evidence: Chimpanzees and gorillas have similar skeletal features.

   Reasoning: Chimpanzees and gorillas both have opposable thumbs and similar ribcages.

3. Claim: Chimpanzees and gorillas may have a common ancestor.

   Evidence: Similar skeletal features likely indicate a common ancestor.

   Reasoning: Chimpanzees and gorillas both have opposable thumbs and similar ribcages.

4. Claim: Chimpanzees and gorillas may have a common ancestor.

   Evidence: Chimpanzees and gorillas both have opposable thumbs and similar ribcages.

   Reasoning: Similar skeletal features likely indicate a common ancestor.