One of the biggest problems brought up, especially by Clive Ponting in chapters 3 and 4 of A Green History of the World was exactly when and why our ancestors began to use the agricultural techniques we use today. Was it something planned, or did agriculture spread over the world because it was a necessity? Ponting points out that when looking at the hunter-gatherers around today, one can see “How easily hunting and gathering groups can obtain sufficient food” (20). Although these groups are very dependent on environmental factors such as droughts, their lifestyle allows for a relaxed time schedule. So why was there a move away from this type of society? The answer to me lies in the increased marginalization of tribes when around 10,000 years ago the population of the Earth grew to around 4 million. As a society, hunter/gathering groups can only maintain certain populations if given enough land, just as animals alive today need a certain amount of space. It is known that some groups practiced population control such as the infanticide of twins and the handicapped, protracted weaning, and abandoning of the elderly. All of these that helped maintain a balanced society that did not do too much damage to the ecosystem that they were living in (Ponting, 23). But some tribes just split into groups when their population got to large. Eventually, this continued separating forced some groups onto marginal land and caused all groups to have less area to roam. It seems that with this pressure early humans were required to make a change in the way that they lived.
There is some evidence that hunter/gatherers did change the environments in which they lived, even before the introduction of agriculture. With the help of fire, groups would burn swaths in forests that helped plants that they favored grow. These subtle changes could be counted as a primitive form of agriculture, in that it is altering an ecosystem to promote the growth that was desired. These practices could have provided a stepping stone into more established agriculture.
There is evidence that pre-agricultural humans could have caused major changes in their environment. Two NPR radio clips examined the change in the Australian wildlife and land around 50, 000 years ago, when humans supposedly traveled and settled there. Around the same time, the Australian megafauna, including a giant kangaroo and a snake two feet in diameter, went extinct. There are three possibilities for the changes. The first is that 50,000 years ago was the end of the last ice age, and so some of the environmental and fauna changes could have been due to climate change and not human destruction at all. Besides the naturally changing climate, there are two other ways that this could have happened: diseases brought by humans could have killed the megafauna, or the use of fire could have changed the environment so drastically that certain species went extinct and Australia became the desert environment known today.
Australia appears to be a place that humans altered in order to create an environment around them that suited their lifestyle, as modern humans do today. This change could not have been possible with out the use of fire. Around 10,000 years ago, humans had spread to cover the entire globe. Without a way to survive in some of the freezing temperatures, it is unlikely that they could have survived and evolved into the dominant species that we are today. It seems that the use of fire is ever-important in understanding the spread of humans, and their success as the top predators. Fire is one of the most useful technologies that humans ever invented. It is an example of how humans altered the environments around them, as well as a way changing climates influenced a change in human behavior.
Mary Stiner brings up another way of looking at the evolution of humans. It was not simply them shaping the environment to their needs with things such as fire and agriculture, but the environment shaping the evolution of humans. Stiner says that humans are a “highly predatory variant of primate”. She notes that we are almost more closely related to other large carnivores than we are to other primates. Essentially, humans had to fight for the top spot in the food chain. To do this, early humans adopted some techniques used by other large carnivores. Humans did not simply kill something and eat it up. Instead, they had the ability to transport and process food. This ability must have emerged not only because of new morphology (standing up right) allowed it, but also because it was needed in order for humans to survive. Humans who did not adapt to the new life style did not live. In this way, the environment surrounding our ancestors shaped their way of life.
Agriculture, fire, and the similarities between humans and carnivores seems to show the dependence of humans on their environment, and the influence both have on each other. There was a need for all of the adaptations; from lack of space, to changing climate, to the need to create a place in an ecosystem. But though the environment shaped human evolution and society, humans changed the environment in which they lived as well.
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