Peter Brannen is a science journalist and in this audio book he talks (or more accurately, Adam Verner talks, since he's the actual narrator) about the five major extinctions that Earth has endured. These are far from the only extinctions Earth has seen in its four billion year plus history, but they are the most significant ones. Arguably, one major event that is relatively recently being recognized - something which destroyed at least a third of marine life diversity, and a significantly larger proportion of terrestrial diversity - is the end-Guadalupian extinction which took place ten million years before the Permian. Brannen does not mention this one. I don't know why. Perhaps since it's so close to the Permian he considers it all part of the same thing. Ten million years isn't a lot in geologic time after all!
As Brannen makes clear in his disturbing evocations, these events were truly horrific times, when the planet was brought to its knees in a series of nightmare scenarios. Earth froze or was virtually boiled, and or was shaded with debris and poisoned with noxious gases from volcanic or impact events, and nearly all life became extinct, only to resume when the crisis was over, to redevelop, re-evolve, and to spread widely and fantastically; then to be culled severely again by the next global tragedy. It's a miracle anything survived at all, let alone enough to allow humans to grow out of what came before.
The thing is though that only one of these extinctions can really be laid at the door of an asteroid impact. That's the most famous one - the dino extinction, and even that cause is disputed. The others? Climate change. The same sort of thing that is going on now, right under our noses, the only difference being that in the past it happened quite slowly whereas we are heating-up the planet far faster than anything nature has ever contemplated.
No other review I've seen has listed these events, but the five extinctions covered in this book are these:
- Ordovician-Silurian - 440 million years ago
- Late Devonian - 365 million years ago
- Permian-Triassic - 250 million years ago
- Triassic-Jurassic - 210 million years ago
- Cretaceous-Tertiary - 65 Million Years Ago
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There's a reason these geologic periods in Earth's hugely-long history have boundaries and names and it's because of (from our modern eyes) abrupt changes in species diversity and composition. Flora and fauna changed and the period got a different name to mark these boundaries. Amazingly, nightmarish and totally weird organisms grew, flourished, and spread, and then disappeared, only to be replaced by an entirely new set of fantastical creatures. The resilience of nature and the inventiveness it exhibits is astounding.
I really enjoyed this book and fully commend it. My only complaint may have been related just to my copy, but I got this from Chirp and I played it through their app on my iPhone in the car on my daily commute. As usual with these books, it worked perfectly, in this case though for only about eighty percent of the book. Right around that mark, it began giving me grief. Other books have played to the very end without issues, but a couple of books I've had problems with, and this was the second that I can recall. It would play for a minute or so and then stop for no apparent reason. I'd restart it, and it would do the same over and over. A different book I began listening to had no such issues - but it has not reached eighty percent yet! We'll see how that goes. (It went fine!)
Apart from that I have no complaints and commend this book fully as educational and entertaining.
