Which of the following was probably the least important factor in bringing about the Cambrian explosion?
A) the emergence of predator-prey relationships
B) an increase in the concentration of atmospheric oxygen
C) the movement of animals onto land
D) the origin of Hox genes

Question

Quizplus · Accepted Answer

The movement of animals onto land occurred well after the Cambrian explosion and would not have directly influenced the diversification of animal life during that period. The emergence of predator-prey relationships and the origin of Hox genes are both thought to have played significant roles in driving the evolution of complex body plans during the Cambrian explosion. An increase in the concentration of atmospheric oxygen may have also contributed by allowing for the evolution of larger and more metabolically active organisms. However, compared to the other factors, it was probably the least important in bringing about the Cambrian explosion.

Which of the Following Was Probably the Least Important Factor