Why is the late Cambrian thought of as the period of the greatest evolutionary change in life forms in Earth’s history?

Acuvu time remaining 51: 04 there are two different alleles for flower color, p and p. the image shows a purple sweet pea that is labeled with its two alleles for petal color photo by christine matthews pp which is the genotype of the sweet pea? save and exit nex subs mark this and retum