From a historical perspective, what is the reason for the relatively high populations of India and China, compared to places like Europe and South America, for example? Were the Indians and Chinese of the past comparatively healthier than people in other areas?
Was their agriculture more ‘successful?’
Has the relatively high human population of these areas always been the case?
Was there a time in history that the population density was more 'evenly balanced' over populated areas as a whole? (For example, at some point in history, have all populated areas had generally the same population density? If so, why has this changed?)
This may be more of a Social Science question, but I am really interested to understand how population density has changed - or not changed - over the last, say 4000 years.
I can't really understand what it is about India and China that has, for such a long time, supported such a large population compared to other parts of the inhabited world.
The short answer is crop yield. Rice has a very high yield and a much higher nutrient content than most other agricultural crops. An acre of planted rice produces much more food with a higher nutrient density than an equivalent acre of wheat or barley, resulting in a larger yearly surplus and therefore can sustain higher populations on an equal amount of land.
Rice also has the advantage over wheat and other grains in that it requires very little processing in order to obtain an edible product. With wheat, the chaff must be separated from the grains, which then must be ground into flour and only then can it be cooked and consumed. Rice, on the other hand, once separated from the chaff can be cooked directly without further steps. (Although further milling may be desired to remove excess bran from the rice, turning "brown rice" into "white rice".)
Rice does require more water to grow than wheat, but the monsoon rains of India and the fertile river valleys of China (fed by the monsoon rains falling in the Himalayas) have long been prime rice-growing areas that had plenty of water and as a result have been capable of supporting massive populations.
If you are interested more in this subject I would recommend Kenneth Pomeranz's The Great Divergence.
I'm sorry, I don't believe this explanation. There are several problems with it:
Rice is not higher yield than wheat. Both plants have the same photochemistry, and are roughly equivalent in terms of their efficacy at converting sunlight to food. In India, wheat yields are higher (2.9 tons per hectare) compared to rice (2.3 tons per hectare). Of course, yields were much lower for both in the past, but I don't see why rice yields would be higher.
Wheat has been cultivated in the Indian subcontinent for as long as rice. There is evidence of wheat cultivation as early as 8000 - 6000 BC at Mehrgarh. The Indus Valley Civilization practiced mixed farming, and cultivated both rice and wheat (as well as barley, legumes, and a number of other crops).
Rice does not have a higher nutritional content than wheat. It does have about 10% more calories than wheat, but on the other hand, wheat has 75% more protein than rice. Nutritional value is a mix of a number of things, it's not determined by calories alone.
I don't know much about the history of agriculture in China, but I do know a bit about its history in India. India has always had a mixed system, with both rice and wheat grown as staples through antiquity. There are regional differences (more rice in the south and east, more wheat in the north), but the subcontinent has produced both in vast quantities for many thousands of years.
Here's why I think India (and perhaps the same reasons are partly applicable to China too) has always had high populations:
India has a tropical climate and multiple growing seasons in the year. In fact, traditionally, Indian crops are divided into rabi and kharif -- rabi being sown in winter and harvested in the spring, and kharif being sown in spring and harvested in late fall, which is the monsoonal season in India. Wheat is a rabi crop, rice is kharif. They don't interfere with each other -- in many parts of north India, both wheat and rice are grown on the same land seasonally. Indian rice is typically not deep water rice (grown in alluvial floodplains of S-E Asia) but rather it's shallow water rice, which does not require full submergence in water. So the reason why India could support a large population was because it grew a lot of food in multiple growing seasons, not because they grew rice. They grew lots of crops, including many other cereals, which were dominant in different parts of the subcontinent.
India has huge amounts of arable land. This often comes as a surprise to people, seeing that India is only the 7th largest country in the world, far behind such giants as the US or Canada or Russia or China. But if you rank countries in terms of arable land, India is second -- slightly behind the US, but ahead of China, Russia, Brazil, Canada. If you throw in Pakistan (which is a 70-year old creation), then India has the largest amount of arable land of any country in the world.
So the reason why India had such a large population was because they have the largest area of arable land, and the fact that the climate allows 2 or more growing seasons every year. China is not far behind, and it seems likely that they also supported large populations for the same reason. The anomaly here is not India or China, but rather the US. Why did the US not produce similarly large populations despite also having large amounts of arable land. They didn't have rice or wheat, but they did have corn, which has a higher yield than both rice and wheat. In fact, corn has the highest yield of any cereal crop.
I suppose it may have to do with being part of the new world, and many old world improvements in agricultural technologies not reaching them until late. The absence of large domesticated animals to pull plows and break earth, the fact that many tribes weren't agricultural tribes to begin with, but were hunter/gatherers instead probably also factored in.
Do you have any source recommendations for further investigation into this topic?
三楼EvanRWT 2 赞同
Which information in particular? I've covered several different disciplines in my post - history, geography, biology, food production. Could you be a bit more specific?
For history, I recommend M.S. Randhawa's "A History of Agriculture in India". It's a multi-volume set, but the first volume covers the period of interest, from the beginnings of agriculture to the 12th century. It's published by the Indian Council of Agricultural Research. Here's a PDF copy of the first volume.
Another good source is the collection titled "History of Science, Philosophy and Culture in Indian Civilization", edited by Chattopathyaya. This is also a multi-volume set, but Volume 5 covers the history of Indian agriculture.
In addition, pick any book on ancient Indian history to understand the general context. Specifically early neolithic sites associated with farming, such as Mehrgarh, some coverage of the Indus Valley Civilization, the later shift of population centers to the Gangetic plain. I don't have any particular recommendations, just any book that covers these periods.
Regarding crop yields, I would recommend reading a primer on the evolutionary history of grasses. Almost all modern cereal crops - including wheat, rice, barley, etc. - are grasses, which appeared relatively recently in the geological record. In particular, you would want to read about the different kinds of photochemistry used by plants to harness solar energy into the production of food. This gets somewhat technical, and I don't know your biology background, but you would need to understand the mechanism of photosynthesis, and the different types of photosynthesis - C3, C4, CAM - that are used by plants, and how each type sets limits on yield based on environmental conditions. What the limiting factors or bottlenecks are for each kind, is it sunlight, is it carbon dioxide, is it moisture. You can start with a basic primer like this one, and then go from there.
Regarding geography, there is not much to say. A good physical atlas of the world is a great starting point, and there are dozens on the internet. Vegetation maps and maps that show climate zones that can be overlaid on relief maps will give you an idea of the extent of these farmlands in different parts of the world.
If you are looking to verify specific facts I mentioned in my posts, please say which one and I'll try to find a reference for it. I provided a link for the areas of arable land by region in my previous post. Here's a link showing why northern India has such a huge alluvial plain - because the flow of the Ganges-Brahmaputra-Meghna system is immense, the 3rd largest in the world after the Amazon and Congo, and it brings millions of tons of silt down from the Himalayas every year.
如果您想验证我的回复中一些具体的观点，请指出是哪一个，我会设法找到它的参考资料。在我之前的一个帖子里，我贴出了区域耕地面积的链接。这个链接解释了为什么印度北部有如此巨大的冲击平原——因为恒河 - 布拉马普特拉河 - 梅克纳河流域的流量如此巨大的，是继亚马逊河流域和刚果河流域之后的流量第三大的流域，每年从喜马拉雅山脉上冲刷下来的泥土有数百万吨之多。
四楼Forgotmyoldlogon 2 赞同
OP here, follow up question: I was more curious about the population density disparity between Europe (the entire continent as a whole,) and India and China throughout history.
I understand now that agricultural practices can have a big impact on population density; does it follow that Europe simply has less arable land than China and India - or a lower crop yield in general?
My curiosity about rice has been piqued. (I have heard that rice and beans are a 'perfect protein,' but I may be wrong about that.) Any idea why rice was/is not such a widely eaten staple food in Europe? Has rice been grown in Europe historically? (The explanation of rice being less labour intensive to go from field to fork made sense to me.)