Unit Overview

Students investigate evolution evidence discovering three types prove common ancestry across species. Through examining Evie Loo's Natural History Wing fossils or analyzing transitional form mysteries, rotating through stations comparing anatomical structures, embryological development, and fossil sequences, and engineering devices monitoring ongoing evolution like antibiotic-resistant bacteria, students master analyzing evolutionary relationships using fossil, embryological, and comparative anatomy evidence lines.

  • Lesson 1
    Lesson 1: Solve: Common Ancestor Mystery + Vocabulary Mind Map

    Solve: Common Ancestor Mystery + Vocabulary Mind Map

    Evie Loo's will names Pongo the orangutan, P-Jon the bird, and Lil' Swimmy the fish as her family. Lawyers declare it invalid—they're not related! Students follow Mosa through Evie's mansion's Natural History wing, gathering three types of evidence: fossil evidence (transitional forms showing evolutionary changes), embryological evidence (all vertebrate embryos look similar early on, sharing gill slits and tails), and comparative anatomy (homologous structures like human arms, bird wings, and whale flippers share the same bone arrangement). The verdict: all species share a common ancestor, making them technically family. The Will stands!

  • Lesson 2
    Lesson 2: Make: Gather Your Own Evidence

    Make: Gather Your Own Evidence

    Three evidence-gathering stations. Station 1: Anatomical Structures—Students compare bone arrangements in human arms, bird wings, whale flippers, and bat wings, discovering homologous structures that prove common ancestry despite different functions. Station 2: Embryos—Students examine vertebrate embryo cards (fish, birds, turtles, humans) at different developmental stages, identifying shared early features (pharyngeal arches/gill slits, tails, limb buds) that later diverge. Station 3: Fossils—Students arrange whale fossil sheets chronologically, reconstructing evolutionary history from land-dwelling ancestors with legs to modern aquatic whales. They complete Evidence Journals explaining how each evidence type supports evolution.

  • Lesson 3
    Lesson 3: Engineer: Engineer a Device that Monitors Evolution

    Engineer: Engineer a Device that Monitors Evolution

    Design a device to monitor that evolution is still happening within a species right now. Students research modern examples of observable evolution (antibiotic-resistant bacteria? pesticide-resistant insects? climate-adapted animals?), identify traits that are changing, then engineer monitoring devices—maybe automated cameras tracking beak sizes in finch populations, sensors measuring wing length changes in moths, or sample collectors tracking bacterial resistance rates. They present designs explaining how their devices gather data proving evolution continues in real time, not just ancient history.

  • Next Generation Science Standards
    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 of life on Earth under the assumption that natural laws operate today as in the past. [Clarification Statement: Emphasis is on finding patterns of changes in the level of complexity of anatomical structures in organisms and the chronological order of fossil appearance in the rock layers.] [Assessment Boundary: Assessment does not include the names of individual species or geological eras in the fossil record.]
    MS-LS4-2
    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. [Clarification Statement: Emphasis is on explanations of the evolutionary relationships among organisms in terms of similarity or differences of the gross appearance of anatomical structures.]
    MS-LS4-3
    Analyze displays of pictorial data to compare patterns of similarities in the embryological development across multiple species to identify relationships not evident in the fully formed anatomy. [Clarification Statement: Emphasis is on inferring general patterns of relatedness among embryos of different organisms by comparing the macroscopic appearance of diagrams or pictures.] [Assessment Boundary: Assessment of comparisons is limited to gross appearance of anatomical structures in embryological development.]
  • Inquiry Scale
    • Each lesson in the unit has an Inquiry Scale that provides directions on how to implement the lesson at the level that works best for you and your students.
    • “Level 1” is the most teacher-driven, and recommended for students in 4th-5th grades. “Level 4” is the most student-driven, and recommended for students in 7th-8th grades.
    • For differentiation within the same grade or class, use different inquiry levels for different groups of students who may require additional support or an extra challenge.
  • Common Misconceptions
    • In everyday language, the word “theory” means a “hunch” or “idea.” Students therefore tend to think the word “theory” has the same meaning in science. Encourage students throughout the unit to recognize that the word “theory” in science means something much different: in science, “theory” means a well-tested hypothesis that has lots of data to support it.
    • Students tend to think that species can “choose” to evolve in order to meet the needs of different environments. Emphasize that this is not possible. Evolution is not a process that occurs at the “individual” level, but rather at the level of the population. Evolution is a passive process driven by the combination of environmental changes and mutations. In conditions where an environmental change occurs (drought, volcanic eruption, new predator, disease in the population), those species with beneficial mutations that cause favorable traits survive and pass on these traits to their offspring. Those that do not have beneficial traits will die, thus creating a shift in the population, leading to a change in the species over time.
    • Students may think that evolution is a process that can occur quickly, even overnight. Emphasize once again that evolution is a process that usually occurs over many generations and is dependent upon beneficial mutations and the specific environment. Note: Evolution is typically a slow, gradual process - but there are examples of rapid evolutionary change.
  • Vocabulary
      • Evolution
      • Fossil Record
      • Embryology
      • Anatomy
      • Vertebrate
  • Content Expert
    • Mohamed Noor
      Professor of Biology Duke University
  • Leveled Reading

    * To give our users the most comprehensive science resource, Mosa Mack is piloting a partnership with RocketLit, a provider of leveled science articles.

    • Evidence for Evolution: Analogous and Homologous Structures

      The fossil record provides a wealth of evidence for evolution, both in organisms who've evolved similar structures in the same environment and organisms who are genetically related that share similar traits. This article give a few examples of each and explains the difference between the two.

    • Speciation - How Evolution Happens

      How does a new species form? In this rigorous article, we look at famous examples (such as Darwin's Finches!) and explain a few different factors that can lead one population to separate and diverge into independent species that can no longer have offspring.

    • How Do Birds Stay Warm?

      Birds have many behavioral adaptations that allow them to stay warm in the coldest regions on Earth. This article reviews a few of the behaviors of birds that help them to survive and also explains how countercurrent blood flow works.