Appropriate Moments in Reading, Volume 9

I took a quick look at the bookshelves a few minutes ago, sighed in some disgust at myself, then started moving stuff around and trying to make all of the shelves look a bit more tidy. The result?



Don't judge me. I've had a bibliomania problem for a long time, but honestly, it's getting better (the Kindle app for my iPad has genuinely helped here).

On the positive side, apart from the reoranganisation, I found a book that I only vaguely remembered picking up last summer, but one which seems particularly appropriate considering the local weather today: Snowball Earth, by Gabrielle Walker. Since first learning about this hypothesis a few years ago, I've been fascinated by the notion of the Earth essentially being a bit like Hoth from The Empire Strikes Back, in what is now known as the Cryogenian Period. The Snowball Earth hypothesis suggests that, somewhere between 650 and 750 million years ago (a number I see sometimes which is right in between those is 700 MYA), the planet essentially froze. Because this freezing effect would have killed off many members of closely related species, the suggestion of the hypothesis is that, for reasons we won't go into here, this die-off may actually have kick-started the proliferation of multicellular life, which characterised the later Edicaran and Cambrian eras.

The evolutionary pressure of the high relatedness in the context of a post-glaciation population boom may have been sufficient to overcome the reproductive cost of forming a complex animal, for the first time in Earth's history."

This is obviously a hypothesis that is still the subject of some debate, but it does fit a large number of the facts available to us from rocks of this age (700MYA, +/-50MYA).

So, rather than focusing on the snow outside, which is (a) merely weather, rather than climate, and (b) absolutely nothing compared to what might have gone on in the Cryogenian, never mind in the last Ice Age, I can sit back and read into some geological history, safe in the knowledge that it can absolutely get worse.

Or, alternately, perhaps I've got a good book about a nice warm tropical island to read instead?