Jared Diamond Continental differences in history

The uni held its annual Sir Douglas Robb lecture series this week, with a series of lectures by Jared Diamond.

The first lecture (on Wednesday night) was essentially based on his book Guns, Germs and Steel. It won a Pulitzer Prize (among other things), and I can highly recommend it.

He essentially tries to answer the question of why it was Eurasians (and largely Europeans) who colonized/killed Africans, Americans, Australians and Polynesians, and not the other way around.

The immediate answer is actually fairly obvious: at the time the different civilisations came into contact, it was the Europeans who had the guns, armor and superior weapons, they had nasty communicable diseases to which the other people had no immunity, and they had steel tools which enabled highly productive societies. Those proximate causes are fairly well understood and established.

If you look back to when the world emerged from the last ice age some 10,000 years ago, humans everywhere were stone age hunter-gatherers with essentially the same basic lifestyles and technologies. During the 10,000 years, something happened that allowed Eurasian civilisations to progress faster than the others. That something is the ultimate cause of Eurasia dominating the world today. What was that something?

The most visible difference between the various civilisations is physical: different peoples look different in their facial features, hair and skin colour. For centuries, racism has been so ingrained that nobody bothered to ask about continental differences: they "knew" the answer was that their race was superior and the other peoples were less intelligent, less hardworking, less skillful or whatever.

It's only really in the last few decades that we have been able to recognise that there really aren't significant differences between the peoples of different continents, and can instead start looking for other answers.

Jared Diamond provides a number of bio-geographical factors that can account for the different rates of societal advance on the different continents. At no time does he claim that these are the _only _factors - he just sets out to show that these factors can account for a very large chunk of the differences.

Natural abundance of domesticable animal species

Very few wild mammal species have ever been domesticated by humans, and all of those were domesticated long ago. There are a number of attributes an animal species must have to be suitable for domestication, and lacking any one will rule it out. Some animals cannot be corralled or penned, either because they can leap so high they can jump out, or because they go crazy in confinement and literally kill themselves trying to escape (gazelles & some deer species). Some animals will not breed in captivity, because their mating rituals require privacy, or extended time or space, or the exact right mix of genders (cheetahs). Some animals are just too dangerous and unpredicable to keep around (bears or tigers). Some animals are just too difficult for humans to find food for (anteaters). Some animals just don't have a herd instinct and don't do well in groups (cats and bighorn sheep). Some animals have far too long a lifespan for us to be able to breed them and have much influence on their evolution (elephants). Even with today's knowledge, we have been able to tame individuals of some of these species, but we have still not domesticated them.

Of the larger mammals then, this leaves us then with domesticated cows, sheep, goats, horses and pigs. Of lesser importance were donkeys, camels, llamas, raindeer, yak and water buffalo. All of these animals except Llamas were native to Eurasia. The Llama was pretty much the only domesticable large mammal in the Americas (and it was only in the South American highlands), and there was nothing in Australia, Papua New Guinea or Africa. The Americas had more large mammals that may have been candidates, but most of them disappeared around the end of the ice age (when people first inhabited the continent).

Natural abundance of domesticable plant species

This is a similar story to the animals - very few wild plant species are suitable for domestication. Of those that are, most occurred in Eurasia. Agriculture is believed to have been independently 'invented' separately in a few different locations, and spread to other areas from there. The fertile crescent region of the middle east was particularly lucky, with 8 very useful species that were suited to domestication. Most other areas only had one or two species available.

Immunity to communicable diseases

This is strongly related to the previous two factors. Because the natural resources in some areas gave those societies a much more productive agriculture, they had dramatic increases in population density. As well as people living in much closer proximity to each other, and living in larger groups, people were in close proximity to herd animals with their own diseases. Most of our communicable diseases came from our domesticated animals: pigs, cows, sheep and so on. In a small or less-dense population, the disease eventually dies out (either because everybody has either died or become immune). When the population becomes large, the disease can live on 'moving' through the population and eventually coming back to infect new victims. With the disease constantly present, the population quickly builds up immunity to the disease.

Development of writing and technology

Again this is related to the first two points. The societies that achieved the most productive food production were able to support non-food-producers, who could develop technology and writing. The technology and writing usually fed back into society to enable to expand more easily, or to directly improve the productivity of the food production, thus supporting even more non-food-producers.

Orientation of the continents

The major axis of Eurasia is east-west. The major axis of the other continents is essentially north-south. This plays quite a significant role in the relative development of the different continents. It is relatively easy for food production to spread in an east-west direction. Because it is the same latitude, it is generally the same climate, the same day length and the same germination cycle. However, spreading north-south is much more difficult. Crops that grow well at one latitude often won't grow at all a bit further north or south, because of the difference in germination cycles and daylight hours, not to mention the climate change. Developments in different parts of Eurasia fairly quickly spread throughout the continent, providing new crops and animals to the peoples there. However, developments in the Americas were hampered by the axis and geography of the region. The crops and Llamas in the Andes never met up with the crops and wheels in Mexico, because the tropical isthmus of Panama lay between them.

Jared Diamond weaves together all these factors into a very compelling explanation of why the Eurasians had all the guns, germs and steel. I highly recommend you read the book.