Mass Extinctions and the Tree of Life

The video explores the concept of extinction, highlighting that for every species alive today, many others have perished. It discusses the causes of extinction, including competition and cataclysms, and provides an overview of five mass extinctions in Earth's history, with a focus on the worst one occurring 250 million years ago at the end of the Permian era.

What is the Tree of Life a metaphor for in the context of extinction?

• A literal tree that holds the secrets of life

• A monument dedicated to extinct species

• A fictional concept in a novel

• A diagram showing the evolutionary relationships among species

What are the two main causes of species extinction mentioned?

• Everyday competition and catastrophic events

• Predation and disease

• Habitat loss and pollution

• Climate change and human activity

How many mass extinctions have occurred in the last 500 million years?

• Six

• Five

• Four

• Three

Which era ended with the worst mass extinction?

• Cretaceous

• Permian

• Jurassic

• Triassic

Approximately how many years ago did the worst mass extinction occur?

• 150 million years ago

• 200 million years ago

• 100 million years ago

• 250 million years ago