Why do we believe the Cambrian explosion occurred so suddenly?
A) oxygen concentrations reached critical levels necessary to support more complex life
B) organisms became sufficiently complex that more diversity became possible
C) climate change due the end of the last snowball Earth phase
D) all of these

Question

Quizplus · Accepted Answer

The sudden appearance of diverse animal phyla during the Cambrian period is believed to have been caused by a combination of factors including increased oxygen levels, the development of complex body plans, and a period of climate change following the end of the Snowball Earth phase.

Why Do We Believe the Cambrian Explosion Occurred So Suddenly