Name: A theory of Earth's mass extinctions
Uploaded: 2009-01-27T01:00:00Z
Duration: 19 min 22 s
Description: Asteroid strikes get all the coverage, but "Medea Hypothesis" author Peter Ward argues that most of Earth's mass extinctions were caused by lowly bacteria. The culprit, a poison called hydrogen sulfide, may have an interesting application in medicine.

Asteroid strikes get all the coverage, but "Medea Hypothesis" author Peter Ward argues that most of Earth's mass extinctions were caused by lowly bacteria. The culprit, a poison called hydrogen sulfide, may have an interesting application in medicine.

Peter Ward: A theory of Earth's mass extinctions

A theory of Earth's mass extinctions

Mass extinctions, often thought the work of asteroids, are largely due to bacteria and their hydrogen sulfide production.

Our planet's complex life teeters on a delicate balance, threatened by the same forces that once caused mass extinctions.

Earth's mass extinctions, often attributed to asteroids, are predominantly caused by microbial actions producing hydrogen sulfide.