CKSci Unit 6: Natural Selection and Common Ancestry
Focus:
In this unit, students investigate the phenomenon of similarities among organisms that seem to be related and ask questions about how these organisms are the same and different from fossils that have similar structures. What can explain the interconnectedness of these organisms? The subtitle of this unit is How could living things today be connected to things that lived long ago? Starting with an examination of extant and fossil penguins, students observe morphological similarities and differences. Then, by examining horses and horseshoe crabs, students expand their understanding of connections between things that lived in the past and those that are living now. Step by step, students develop a model that might explain how organisms change over time. They examine the possible role of environment as they develop models of natural selection and possible common ancestry. This unit allows students to observe the phenomena of a force acting through a distance in detail and then spend time working with classmates to analyze their shared experience, formulate new questions, and develop new strategies for answering them. Students explore concepts that include the following:
- How could penguins and other things living today be connected to things that lived long ago?
- Why are there similarities and differences in the body structures of modern and ancient penguins?
- How could organisms living today be connected to organisms that lived long ago?
- How do traits found in a population change over a shorter amount of time?
- How well does our General Model predict and explain the changes happening over time in a different population?
- Can we apply the General Model for Natural Selection over millions of years to explain how all the ancient and modern penguins are connected?
As students move through their day-to-day activities, they will also read Core Knowledge literacy selections. These include factual articles, history of the sciences, art and literature, spotting bad science in the media and advertisements, graphics comprehension, research-type articles, reliability of sources, and other areas of science literacy.
Number of Lessons:
- Teacher Guide: 15 Lessons
- Student Reader: 4 Collections
Instruction Time (Student Reader):
- Lessons are designed to be completed in one or more class periods.
- A Pacing Guide found in Online Resources offers a suggested time to complete the entire unit if class is held each day.
- The entire unit should take about 31 days to complete if class is held each day.
- A complete list of Materials needed to complete the unit is provided in Online Resources.
Additional Search Terms:
science literacy • evolution • natural selection • common ancestry • fossil record • species • mass extinction • convergence • phylogeny • adaptation • artificial selection • speciation • nonfiction • informational text
