That Time Oxygen Almost Killed Everything

• 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.

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.
  

This resource addresses the listed standards. To fully meet standards, search for more related resources.