Hard to consider something that occurred over a period of 50 million years and explosion. But the Cambrian was also geologically active period with the creation of the Appalachians and continants splitting and recombining. Lots os new stresses and new niches. Arthopods ruling the fauna and flora creating an oxidizing environs to replace the reducing one.
I has a High School Freshman Physical Science Class prepare a scaled timeline in the hall of the school hall in the plains of Colorado--starting with the formation of the earth and ending with Rome. It was up during the fall semester parents teachers conferences and I recieve a few complaints from parents, because it offended their biblical sensibilities. In the spring I had this class construct a scale model of the solar system in outside along the side of the football and baseball fields. Again I recieved complaints from the same parents for the same reasons.
My contract wasn't renewed the next year--I put it down to the following factors. I wasn't a local, I offended sensibilities by illustrations of how insignificant the human species and this little rock really was (especially as Proxima Centauri, the nest nearest star, was in Wray, w25 miles away), I rode a bicycle on Sunday morning, science was in conflict with biblical innerrancy, and the student body was rapidly becoming a hispanic majority as the local arga-business became corporate.
I learned something from that experience--corporations don't really want an educated and curious workforce--they prefer a trainable one, there's a significant hostility when you expose a dissonance between facts and long term fictions, I didn't like teaching adolescent teens in classrooms, I am not suited to life in the arid plains. I guess its all well that I abandonded that life.