Which of the following was the least likely factor causing the Cambrian explosion?
A)the emergence of predator-prey relationships between animals
B)the accumulation of diverse adaptations, such as shells and different modes of locomotion
C)the movement of animals onto land
D)the evolution of Hox genes that controlled development
E)the accumulation of sufficient atmospheric oxygen to support the more active metabolism of mobile animals

Question

Quizplus · Accepted Answer

The movement of animals onto land occurred much later, during the Devonian period, and thus was not a factor in the Cambrian explosion which occurred during the early Cambrian period. The other factors listed were all major contributors to the Cambrian explosion.

Which of the Following Was the Least Likely Factor Causing