A Darwinian Survival Guide: Hope for The Twenty-First Century II

The middle section of the book covers human history over the last 11,500 years. This is an immense timeframe as far as humans are concerned, and I am attempting to incorporate the information included here with what I already knew. We don't know much detail about anything that occurred over 5000 years ago, but the main change was the development of agriculture. This is widely seen to be the underlying cause of changes from the nomadic hunter-gatherer lifestyles that had facilitated the survival of humans during the last Ice Age. Agriculture led to sedentary lifestyles that gradually permitted the development of small towns and, eventually, cities. One of the strengths of humans as nomadic organisms was their ability to just move on whenever conditions became undesirable at a particular location. With the sedentary lifestyles that were facilitated by ample local food supplies, new risks emerged. One was the development and spread of new diseases. Another was the need to protect property. Besides local theft and other crimes, the risk of outright invasion gradually increased, and when a city or town was invaded, the local inhabitants often had nowhere to go. Many ancient towns and cities were abandoned, and, over the centuries, this problem has not been solved. Imagine yourself as an inhabitant of the Gaza Strip today.

There were also social changes that occurred during this period, and it would appear that societies gradually became less egalitarian. Among hunter-gatherers, it seems that women and men were treated equally, and that women may even have held positions of authority. By the time of the Bronze Age, about 6000 years ago, improved weaponry seems to have precipitated the growth of patriarchal societies and increases in violence and wars. In many parts of the world, there was a gradual shift from polytheism to monotheism. Not coincidentally, the monotheistic religions tend to be built around all-powerful male gods. The best example that I know of regarding the evolution of warlike behavior is the Yamnaya culture, which dates from the Bronze Age. They were technologically advanced for the time, and, starting in Western Asia, moved to Europe and Northern India, with the men spreading their Y-chromosomes everywhere they went. When they arrived in new regions, presumably they killed the local men. They were also the originators of the Indo-European languages, which are now spoken by nearly half the people on earth. As I wrote earlier, the Yamnaya may have been the ancestors of both the ancient Greeks and the Vikings. It is possible that Yamnaya behavior was behind the Trojan War 3000 years ago and the Viking invasions from 793 AD to 1066 AD. The Vikings liked to travel, and they discovered North America nearly 500 years before Christopher Columbus. As time passed, male violence seemed to increase everywhere. This can be seen in the building of large barriers designed to keep out invaders. The Great Wall of China was built about 2000 years ago. Hadrian's Wall was built in 122 AD by the Romans to keep Picts out of England. Offa's Dyke was built in about 757 AD to keep the Welsh out of Mercia, which is now the English Midlands. As far as gene-spreading goes, because of a unique feature of his Y-chromosome, Genghis Khan, who died in 1227 AD, is thought to have 16 million male descendants. Since he was Mongolian, you can't simply say that gene-spreading occurred only in Western Asia, Europe and Northern India. In conjunction with the general increase in violent behavior, it should also be noted that cooperation gradually declined when H. sapiens increasingly encountered people who were not part of their group.

While male violence is a danger of modern life, it pales in comparison to the negative effects of human population growth. 6000 years ago, the world population was only about 7 million. 3000 years ago it was only about 50 million. In about 1800 it first reached 1 billion. By 2075, it is projected to be over 9 billion. It is the collective behavior of modern H. sapiens that has caused the Anthropocene era. This is an era of existential risk for us, though we have the tools available to avert our extinction or near-extinction. In the remaining third of the book, Brooks and Agosta will provide their solutions.