Question

Which of these was not a potential cause of the Cambrian explosion?

1) Predation
2) Increased oxygen levels
3) Evolution of hard body parts
4) Decreased volcanic activity

Answer 1

Decreased volcanic activity was not a cause of the Cambrian explosion; instead, factors like rising oxygen and calcium levels, as well as the evolution of Hox genes, likely played significant roles in this diversification of life.

Step-by-step explanation:

Decreased volcanic activity was not a direct cause of the Cambrian explosion. Rather, the Cambrian explosion, which occurred around 540 million years ago, is attributed to a combination of factors that favored an incredible diversification of life forms.

Two leading theories involve environmental changes and genetic developments. One theory cites an increase in atmospheric oxygen levels and oceanic calcium concentrations, which may have supported more complex life forms. Another points to the development of Hox genes, which allowed for more varied and complex animal morphologies. The idea of decreased volcanic activity does not directly explain the rapid increase in biodiversity and complexity of organisms during the Cambrian period.