Highlighted Phenomena from Integrated Grade 8
- Mass extinctions and species diversification events happen repeatedly in Earth’s history.
- Many impact craters on Earth show evidence that rock melted at the impact site.
- A volcano on Saturn’s moon, Io, has massive eruptions that repeat about once every 1.5 Earth years.
- Very few dinosaur fossils are found in rock layers slightly below the K-T impact boundary (implying that they may have declined before the major impact).
- Satellite observations of net primary productivity show that plants go through seasonal cycles where productivity peaks in the Northern Hemisphere around July and the Southern Hemisphere around January.
Introduction to Integrated Grade 8
Integrated grade eight builds on the ideas of stability and change introduced at the end of grade seven with the guiding concept: “The processes that change Earth’s systems at different spatial scales today also caused changes in the past.” The framework describes a conceptual flow in which students explain different episodes of mass extinction and species diversification during the first three instructional segments and then move to present-day changes in IS4. The course begins with students analyzing data about the diversity of species over the last 500 million years, which reveals evidence of several mass extinction events.
In IS1 (Objects Move and Collide), students address one possible explanation of the mass extinctions: impact by an asteroid. A snapshot shows how a computer simulation helps students develop models of forces and motion. In an engineering connection, students revisit the phenomena of car crashes from grade four. They design a bumper and explain its function in terms of energy transfer, a common theme throughout IS1. Students revisit the idea of extinction by asteroid impact and look for evidence of energy transfer at an impact site.
Instructional segment 2 (Noncontact Forces Influence Phenomena) also uses phenomena from space to help students develop models of noncontact forces (gravity, magnetism, and electric fields). Noncontact forces can be difficult to visualize, so the framework illustrates how teachers can complement hands-on investigations with physical and computational models. In a snapshot, students analyze and interpret data to determine which forces cause gigantic volcanic eruptions on Jupiter’s moon, Io.
Students investigate one mass extinction event in detail by reading fossil evidence in layers of rock like pages of a history book during IS3 (Evolution Explains Life’s Unity and Diversity). To explain why different species exist during each time period, students transition to interpreting data about natural selection and evolution in modern-day organisms. A snapshot on natural selection shows how students can use clothespins in a physical simulation to explain real-life bird population data. Another snapshot describes an interactive computer simulation where students play the role of a genetic engineer of zebrafish as they develop a model of how human hands evolved from fish fins.
A vignette in IS4 (Sustaining Local and Global Biodiversity) emphasizes that natural selection mechanisms continue today in response to human activities. Students engineer devices to track modern sharks using principles of sound, light, and radio waves. Applying tracking data, students develop policy solutions that protect sharks and communicate their solutions to the fishing industry, lawmakers, and beach visitors. To build on students’ understanding of light waves, IS4 also includes a snapshot about installing solar panels to convert light energy to electricity. Observations of how solar panel output varies with the angle of the Sun throughout the day and year motivates students to develop a model that explains Earth’s seasons.
Integrated grade eight ends with a capstone project in which students investigate an environmental challenge. They must explain how humans influence the environment and design specific and detailed solutions that help solve or mitigate the problem.
from d’Alessio, Matthew A. (2018). Executive Summary: Science Framework for California Public Schools: Kindergarten Through Grade Twelve. Sacramento: Consortium for the Implementation of the Common Core State Standards.