2007 Book Challenge 2: Out of Thin Air by Peter D. Ward

Out of Thin Air is a science nonfiction that explains a new theory on the underlying basis for how and why animal life on Earth had the history that it did. In a word: oxygen. The one thing all animals (and plants, and fungi, and protists and most bacteria) must do is breathe - and in particular they must figure out a way to take up enough oxygen to exist. Oxygen levels have fluctuated up and down through the ages, from as high as 35% to as low as 10% (it's 20% today). Times of high oxygen means high species diversity; times of low oxygen means high diversity in body plans.

The book was written by a university professor, and although it was apparently marketed for general public reading, it really requires at least a biology degree for full understanding. I can easily see a semester-long graduate-level seminar course that uses this book as an outline. One chapter at a time, along with all the primary literature that gets cited in support of all the things each chapter says. Lots of discussion on what the heck the author means. In fact, I suspect that the author uses this book for exactly that purpose.

As books go, this one could've used some more revising. The logic is unclear and even circular in some parts. There are also parts where the author starts out stating one thing, then goes off on a tangent and never gets back to supporting the original statement. And many many parts where he makes leaps, assuming that the reader knows things and can follow along if he omits stating a few in-between steps. Overall, it needs to be written from a completely different angle; as is, it looks like he's beating a tiresome drum over and over ("the answer was oxygen levels!"). It could be rewritten so that you don't start with a bunch of questions that lead to the same answer, but with the answer first followed by all the consequences thereof. It would still have the same content, but be a much smoother read.

Several factual things bothered me:

a) Early on he mentioned that birds are able to survive and thrive at much higher altitudes (thinner air, lower oxygen levels) than mammals. However, it isn't until the last hundred pages where he even mentions the setup of their lungs. That is, bird lungs have unidirectional airflow. Instead of a bag that inflates and deflates like ours, where oxygen-rich air goes in and then carbon-dioxide-laden air goes back out through the same paths, bird lungs have a system where air goes in one way and out a different way, and it's coupled to blood flow that moves in the opposite direction. It's a lot more efficient.

I spent a lot of the book wondering how he could've possibly overlooked such a basic fact, when he's writing something about oxygen and breathing. Fortunately for him, he eventually makes up for this lack by going into extreme detail on bird lungs for almost an entire chapter. Not only the details of how they're set up now (which I hadn't actually known fully), but lots of good nuggets of information from paleontology on when and from what it arose, and whether some of the dinosaurs had a setup like it (in the author's opinion: yes). But he needed to at least hint that such a section was upcoming.

b) There are whole sections in the book that strongly imply that lungs evolved from gills. No, they didn't. Lungs and gills are separate organs, and in some fish and amphibians you can even have both at the same time. Modern lungs (such as in us humans) are analogous to the modern swim bladder in bony fishes.

c) He also implies that reptiles evolved from amphibians. I'm fairly certain I read somewhere a while back that they both came from lobefinned fish, but did not evolve from each other. How controversial that was, I don't know - depends where I read it, and I can't remember.

d) Near the beginning he really should've talked more about how free oxygen first came to exist on Earth. The very first life on Earth was anaerobic. Oxygen is actually a toxin and was put out as a waste product. (It's still a toxin; we're just set up to make sure it doesn't do too much damage while we're harnessing it to do useful things). Eventually the first anaerobes polluted their atmosphere with it so much that there were no more rocks left to absorb it (by oxidizing).

Also, "descendant" is the correct spelling.

As for me and the Book Challenge. I actually started reading this back in December, so technically it's half a book I've read for 2007. I received it just before Christmas from a regular customer of the Chinese takeout where I work. He found out I have advanced degrees in biology, so he loaned me the book to read. He said he didn't understand it, and hoped I would be able to explain it to him. Having now read it in its entirety, I don't know if I can, unless I also want to teach him basic biology. It didn't bode well that one of the things he seemed amazed about was "wow, did you know humans came from fish?" This signals to me that we'd have to start with an uphill battle about evolution first...