To a certain extent, I’ve always wondered why Guns, Germs, and Steel caused such a huge splash. The main premise boils down to ‘differences in geography cause differences in societies and their history’, which belongs to the club of the blindingly obvious.
Of course, the real point of the book is to pin down just which differences are the important ones. This is a cause for much arguement, but Diamond has successfully pulled out the most important ones as applied to history as a whole. This largely turns into a study of what plants and animals were successfully domesticated in early prehistory, and how that turned certain areas into the origin of settled agriculture. That is still fairly basic stuff, but benefits greatly from studying the results from all around the world all at once, and examining just what it takes for something to be capable of being domesticated. (I know there’s been some interesting work done on that since this book came out, but I haven’t seen it escape scholarly journals in more detail than a National Geographic article.)
From there, Diamond points out how plants and animals are generally adapted to a certain climate, and that while it is fairly easy to find different climates going east and west (due to cold mountains, dry deserts, wet coasts, and other accidents of geology), large differences of climate are guaranteed when traveling any real distance north and south. Looking at a map and noting that the Americas and Africa are divided into north-south zones, while Eurasia is oriented east-west, then provides material to show why certain areas needed to work everything out independently, while others were able to borrow everything they needed from elsewhere (before the Age of Exploration, the two situations were probably somewhat even by landmass; the book naturally spends much more time looking at the former).
The main thing that makes this book new is actually the ‘germs’ part of the book. It is only fairly recently that we’ve really become aware of where most of the deadly diseases we have to deal with come from—other animals. So societies that have and live closely with lots of domesticatible animals get to suffer from deadly epidemics when an occasional virus adapts to a new host (us), and then develop some level of immunity to it. When people who don’t have much/anything in the way of domesticated animals run into people who do, they die off as multiple epidemics run through the countryside. This is the other ‘new’ part—the fact that a lot of Native American population was wiped out by disease is well known, but it’s been hard to realize the scale of the disaster. The “Mound Builders” were a disappeared pre-Columbian civilization of the Mississippi valley, and only recently has it been realized it was actually wiped out by European diseases before any Europeans got there to see it.
The ‘guns’ and ‘steel’ parts of the book are essentially non-existent. They just serve as part of the proximate cause of how Europeans came to dominate the world before turning to look for the ultimate causes back in prehistory. This is where his biases as a biologist who’s picked up a fair amount of practical cultural anthropology show. While he does discuss technology, and the fact that the wider the range of where you can get ideas from, the more ideas you will be able to encounter, he doesn’t spend any time looking at the basics of physical technology. A basic study of easily available copper, tin, iron, and clay deposits, compared with the areas that were able to develop settled agriculture could explain much that remains mysterious to him.
It’s decidedly a layman’s book, and has the advantage of being aware of more current research than any pre-college textbook. The fairly breezy, non-technical writing is set off by a good number of informative charts and maps and allow Diamond to make his points without miring himself in the minutia that would lose the non-dedicated reader. Just being able to tackle most of pre-history in a single reasonably-sized volume is an impressive feat of summarization, and the most impressive thing about the book.
