Chapter 7 - How to Make an Almond

Maxwell Gerber

College Writing R1A

Peter Vahle

Guns, Germs, and Steel Chapter 7 Outline

Chapter 7 concerns itself with how crops became domesticated in prehistoric times. All crops we currently farm originated from wild plants. Why did certain wild plants get turned into crops, and not others? Why did certain crops, strawberries, for instance, take thousands of years to develop, while others, such as wheat, were domesticated over a short time frame? And why do some viable food sources, such as acorns, still elude domestication?

Plants lack the ability to distribute their offspring, so they must rely on the wind or animals to do the job for them. This led to the evolution of fruit filled with seeds. Animals eat the fruit and defecate the seeds miles away. Fruits that are larger, more colorful, or sweeter would be preferred by animals, and those seeds would have had a better chance of being distributed.

Just as animals unconsciously coaxed plants to grow in a way that was beneficial for them, early humans unconsciously coaxed wild plants to resemble modern day crops. Hunter-gatherers would obviously target the largest wild strawberries and the best-tasting almonds. These seeds would, hypothetically, end up in the communal latrine and grow up close to the human settlements. At some point, someone made the connection between seeds and plants, and began to farm. Wild almonds are potentially poisonous and very bitter and wild bananas have large seeds. But prehistoric farmers would only plant seeds from the best crops. By harvesting wild plants with desirable features, the process of domestication was started.

However, there were several other factors at work. Genetic mutations played a massive role in this process. For example, wild pea pods explode, dispersing their seeds over a large area. A mutation in the pea pod's genome prevents it from exploding, thereby allowing it to be harvested and domesticated by humans. Wild wheat and barley "shatter", dropping all their seeds into the wind. A similar mutation enabled these plants to be harvested. Both of these issues were controlled by a single gene in the plant. After a single mutation, these plants were eligible for domestication. Other plants, such as bitter acorns, have issues controlled by many genes, requiring many mutations to become eligible. This explains why some plants were domesticated quickly while others took thousands of years.

Another significant factor is the plant's method of reproduction. Some plants are capable of reproducing with themselves, but many must exchange genes with another plant to bear fruit. Suppose a potential crop with a positive gene mutation is planted, but when it bears fruit it must mate with wild plants that don't have that mutation. The next generation of plants might not carry that mutation and would effectively be useless. This meant that the first crops had to be self-pollinating, readily edible, and easy to farm.

In fact, there were several distinct waves of domestication. Twelve thousand years ago, wheat, barley, and peas became domesticated. Six thousand years ago, certain types of fruit trees (olives, figs, dates, pomegranates, and grapes) followed suit. These trees could be grown directly by being planted as cuttings. They took a few years to bear fruit, meaning that they could only be grown by somebody who was committed to an agricultural lifestyle. It wasn't until thousands of years after that the process of grafting was invented in China. Grafting is necessary to grow apples, pears, plums, and cherries. These only became domesticated after farmers consciously began to experiment with the plants around them.

Certain plants still have yet to be fully domesticated by humans, with Oak trees being the most convincing example. Oaks have a long lifespan and take many years to bear acorns. Furthermore, the bitterness of acorns is controlled by many different genes, so it is very difficult to produce a delicious acorn. In addition, squirrels are much more effective at planting and harvesting nuts than humans are. This means that generally, oak trees will always cater towards the needs of squirrels rather than us.

Similarities between Darwin's process of natural selection and principles of crop development by natural selection helped to pave the way to modern botany, agriculture, genetics, etc.

I haven't had the chance to read many chapters leading up to this, so I'm not entirely sure how Diamond's thesis ties together. If I had to guess, I'd say that prehistoric peoples with easier access to wheat and barley would begin to farm first. This farming process would lead to the development of towns, cities, and later governments and large populations. Farming communities would have food surpluses, allowing them to support inventors and artisans. Therefore, it follows that the people who began to farm first would be the first to experiment with new technologies and be the first to develop guns and steel, ensuring supremacy abroad. This is all speculation on my part, however.

What I found particularly interesting about this chapter was the way Jared Diamond logically and methodically makes his argument. He goes strictly in chronological order, starting with the plants that were first domesticated (wheat and barley) and working up to plants that still evade us in the present day (Oak trees / acorns). His presentation of information is well thought out and leaves little room for argument or debate. In addition, he presents such an abundance of background material that his claims are very easy to understand. I had absolutely no prior knowledge of botany or prehistoric agriculture and I was able to follow his claims perfectly fine. If Diamond's goal with this book is to offer concise, logical, and scientific explanations for many different things in a variety of cross-disciplinary areas then he is doing very well with this chapter.

 That being said, I'm not entirely sure how a concise explanation of how humans began to domesticate crops relates back to the idea of modern day distribution of wealth and power. How does the domestication of apples relate to Eurasian economic superiority? After reading this chapter, I find myself more intrigued. If I get the time (HA!) I would love to read this book in full. At the moment, I will be satisfied with my classmate's blog posts.