MS-LS4-2
The standard
Apply scientific ideas to construct an explanation for the anatomical similarities and differences among modern organisms and between modern and fossil organisms to infer evolutionary relationships.
Next Generation Science Standards
What this standard means
Students need to compare body structures in living and fossil organisms, then use those comparisons to explain likely evolutionary relationships. They should notice patterns in bones, limbs, shells, teeth, or other visible anatomy, not just say organisms “look alike.” They need to connect evidence to a claim.
Mastery looks like a clear explanation: “These organisms are likely related because they share this structure, but they differ in this way.” Students often get stuck by comparing size, habitat, or behavior instead of anatomy. They may also assume every similarity means close relationship, without weighing differences or fossil evidence.
Ways to teach it
- Give groups printed skeleton diagrams of a whale, bat, cat, human, and fossil mammal, then have them color matching limb bones.
- Ask students to write: Which two organisms are most closely related, and what anatomical evidence supports your claim?
- Show three organism images and ask students to circle one shared structure and write one relationship claim using it as evidence.
- Compare a modern horse hoof and fossil horse toes, then discuss how anatomy can show change across time.
Plan a lesson for MS-LS4-2
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Related standards
- 1-LS3-1
Make observations to construct an evidence-based account that young plants and animals are like, but not exactly like, their parents.
- MS-LS4-1
Analyze and interpret data for patterns in the fossil record that document the existence, diversity, extinction, and change of life forms throughout the history...
- MS-LS4-3
Analyze displays of pictorial data to compare patterns of similarities in the embryological development across multiple species to identify relationships not ev...
- 3-LS4-1
Analyze and interpret data from fossils to provide evidence of the organisms and the environments in which they lived long ago.