Here is part II of the review; part I can be found here.
The next phase involved forming larger communities and governments, and the specialization of labor. None of this was possible when people were nomadic or beginning farmers, since all available people had to contribute to the farming efforts. But, as people became more skilled and efficient at farming, they were able to develop governments and specialized jobs.
Once not everyone has to help out with farming, some people will have more time available to make further progress. More generally, each invention that humans have come up with comes along with certain prerequisites, and the invention cannot be invented and adopted until those prerequisites are met. And, if we look at some of the great innovations of human society (such as farming, irrigation, writing, usable electricity, and cohomology), it is clear that they must come in a specific order.
These great innovations are built with various degrees of difficulty. As we have seen, farming was difficult, but not too difficult. Much harder was the development of writing. In fact, Diamond claims that this was such a tough task that only two societies (in the Fertile Crescent and Mesoamerica) have discovered it purely independently, with China being a possible third. But it was as very important innovation that required the earlier innovation of farming to be firmly entrenched and mastered by society.
It must have taken a long time to get from the advent of farming to the advent of writing, so societies or continents who were already lagging behind with farming, who had the added disadvantage that sharing didn’t work as well, were at even more of a disadvantage when it came to the development of writing. And a society can’t progress much without being able to write.
Another question Diamond ponders is how much of a difference it makes if societies are technologically conservative or more adventurous. His claim is that, in the long run, given enough people, societies cannot ever afford to be technologically conservative. In any sufficiently large group of people, there will be some who wish to push the current bounds of knowledge, and some of them will invent new toys. Of course, the surrounding society may or may not be receptive to such things. But, if there are enough societies around, at least one will accept new inventions. If these inventions are advantageous, they will spread, possibly by setting an example, possibly by trade, or possibly by conquest. Thus, in a non-tiny population, this really shouldn’t make much of a difference.
That brings us to the components of the title of the book: guns, germs, and steel. It is they that directly allowed Eurasia to conquer much of the rest of the world. I think guns and steel are fairly self-explanatory, but germs demand a bit of explanation. However, Eurasian diseases were responsible for far more deaths among inhabitants of other continents following Eurasian arrival than guns were. That shouldn’t be too surprising, given that a substantial portion of the population of Europe had been wiped out by diseases such as smallpox, cholera, and bubonic plague in the centuries before, and that was in spite of Europeans already having a certain degree of immunity to these diseases. By contrast, people in Africa, Australia, and the Americas had no immunity at all.
All else being equal, we would expect that the germ trade would be fairly balanced, but that was not the case. In many instances, European explorers contacted no diseases indigenous to the lands they were exploring or conquering. But in some cases, they did: tropical diseases such as malaria made the conquest of such lands very difficult, and in some cases it took centuries until they were finally conquered.
In order to understand why the germ exchange was so uneven, we must first know how diseases come to be. Most infectious diseases, including essentially all forms of influenza for instance, are derived from our close contact with animals, especially pigs and chickens, who have been domesticated to be mistaken for food. (Go vegan and help to eradicate the flu!) Originally, these diseases only affect other species, but after some mutations, they can infect humans as well. And since humans live in close proximity with these animals, it is likely that some humans will be infected, and then the disease spreads from there among humans. Hence, the paucity of domesticated animals in other places meant that they had few diseases to return to the conquering Europeans.
We’ve done fairly well in explaining why Eurasia was far ahead technologically of other continents by around 1400 and hence was in a position to take over the world, but at least one glaring omission remains: why was it overwhelmingly Europe that conquered the rest of the world, and not Asia? Why didn’t China fare as well as Spain?
To be continued, once more.