This informative and visually striking video thoroughly explains the role that photosynthetic microbes played in changing Earth's early atmosphere and oceans, from green oceans to red oceans and then global glaciations and extinctions.
Students will learn about the Oxygen Catastrophe mass extinction event and how the oxygen released from newly evolved photosynthesizers completely modified the chemical composition of the biosphere, led to the creation of the ozone layer, and allowed for life to exist on land.
Teaching Tips
Positives
Engaging visuals accompany the narration, so students will easily follow along with the series of events depicted.
The unusual title can be a starting point to gain student interest in the lesson.
Additional Prerequisites
The video speed can be adjusted for learners at different levels.
There is an ad before the video begins.
The vocabulary is rigorous, so teachers may wish to provide a definition list or graphic organizer.
Differentiation
English teachers can print the transcript and then have students highlight vocabulary words before defining them.
More advanced students can use this video to connect to lessons about the causes of historic changes in climate, the effect of molecules such as carbon dioxide and methane on the heat balance of the Earth, and the importance of photosynthesis in the carbon cycle.
Science teachers can have students work in small groups to create hard-copy timelines of the events shown on the screen, then make connections to photosynthesis, redox reactions, the chemical formula for ozone, anoxic bacteria still alive today, or other lesson topics.
Scientist Notes
This video resource discusses how oxygen became more abundant in our atmosphere and what effects this process had on the planet. In the video, the host discusses how changing levels of carbon dioxide and changes in the chemical composition of the Earth’s atmosphere affect the Earth’s temperature, which is a key concept in discussing both natural and anthropogenic climate change. Since this resource explains fundamental information about the topic, it is still considered accurate and up to date despite the resource’s older age. The information presented is accurate and this resource is recommended for teaching.
Standards
Next Generation Science Standards (NGSS)
ESS1.C: The History of Planet Earth
MS-ESS1-C.1. The geologic time scale interpreted from rock strata provides a way to organize Earth’s history. Analyses of rock strata and the fossil record provide only relative dates, not an absolute scale. (MS-ESS1-4)
ESS1: Earth's Place in the Universe
HS-ESS1-6 Apply scientific reasoning and evidence from ancient Earth materials, meteorites, and other planetary surfaces to construct an account of Earth’s formation and early history.
ESS2.E: Biogeology
HS-ESS2-E. The many dynamic and delicate feedbacks between the biosphere and other Earth systems cause a continual co-evolution of Earth’s surface and the life that exists on it. (HS-ESS2-7)
ESS2: Earth's Systems
HS-ESS2-2 Analyze geoscience data to make the claim that one change to Earth’s surface can create feedbacks that cause changes to other Earth systems.
HS-ESS2-7 Construct an argument based on evidence about the simultaneous coevolution of Earth’s systems and life on Earth.