Can we estimate how much life there was on Earth before the Permian extinction events?
We have no way of knowing how densely the Permian world was inhabited or how large the different animal populations were because the fossil record is too patchy and inaccurate. However we do know that what was significant about the Permian world was that, for the first time, practically every ecological niche was occupied. This was a self-sustaining world as complete, in its way, as ours is today. In fact this was the first time such a complete array of creatures had existed. Moreover we know that some of these creatures were in the process of evolving into mammals and were, therefore evolutionarily, extremely sophisticated. The early dinosaur period, which followed the Permian extinction, was much less sophisticated. In this sense, the Permian extinction marks a step back in evolution. Indeed it’s doubtful the early dinosaurs – which were evolutionarily rather primitive – would have been able to find a niche in the world had the more advanced animals of the Permian world not been wipe
