South Dakota Science MS-LS4-2

ScienceGrades 6–8Life Science

The Standard

Apply scientific ideas to construct an explanation for similarities and differences among modern organisms and between modern and fossil organisms to infer evolutionary relationships. (SEP: 6; DCI: LS4.A; CCC: Patterns)

South Dakota Science Standards (2024) · Biological Unity and Diversity

Teacher's field guide

What This Standard Means

What Students Need to Do: Students compare body parts in living animals and fossils. They use shared features and differences to explain which organisms likely share a more recent ancestor.
What Mastery Looks Like: A student can identify matching features in a fossil and two living animals, then choose the likely closer relative. They can explain why one difference does not rule out shared ancestry.
Common Misconceptions: Students may treat a common trait, such as four legs, as strong evidence as a distinctive shared bone. They may assume a fossil is a direct ancestor or that one different body part rules out a relationship.
How to Assess It: Exit ticket: Archaeopteryx had feathered wings, a wishbone, teeth, and a long bony tail; a pigeon has feathered wings and a wishbone; a lizard has teeth and a long bony tail. Which living animal likely shares a more recent ancestor with Archaeopteryx, and which two traits support your answer?

Lesson moves

Ways to Teach It

Give groups diagrams of a three-toed fossil horse foot and a modern horse foot; students align toe bones and mark matching structures.
Show labeled skeletons of a fossil whale with hind legs and a modern whale; ask whether matching ear bones support a relationship despite the leg difference.
Play closest relative with Archaeopteryx, pigeon, and lizard trait cards; pairs choose a match and defend it using feathers and wishbones.
Print mammoth and elephant skull photos from a museum collection; students circle matching tusk sockets and explain what those features suggest.

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