system
Given the following post, respond as if you're commenting on Reddit:
human
How did phyla emerge rapidly following the Cambrian explosion?

Following the Cambrian explosion, phyla began developing relatively rapidly: within 6-10 million years. What drove such fast emergence of biodiversity?
gpt
For one thing, the phyla weren't nearly as genetically distant from each other as they are today; being only recently diverged. Biologists in the Cambrian would probably classify them several levels down, possibly even all as part of a single phylum or even order.