Tuesday, November 30, 2010

Additional Video Links

The following video links are highly relevant to several of the topics discussed throughout these blogs and provide substantive summary and elaboration.

Agriculture: Causing Health Problems for 10,000 Years

The transition of early humans from a hunter-gatherer life style to an agricultural one has led to the formation of a wide variety of health problems. It increased the spread of disease and created settled groups which led to increased conflict. In addition, the advent of agriculture has caused serious health problems which can still be seen in humans today. These include: dental problems, infection, abnormal growth and development, and decreased height.

Agriculture has generally been considered a good thing for humanity’s growth and development. “Pathology and other evidence from human remains reveal, however, that the shift from foraging to farming had generally negative consequences for lifestyle and health.” The changes to the workload and make-up of food that resulted from the creation of agriculture were negative for the health of humanity.

The masticatory functional hypothesis says that the form of the skull began to change because of reduced demands on the chewing muscles. This craniofacial change, which is basically a reduction in the size of the face, jaws, and masticatory chewing muscles, is a direct result of agriculture which caused people to eat softer foods. Eating softer meals seems like it would be a bonus for humanity’s health. Unfortunately it was not.

The eating of softer foods led to a reduced size in the face and mouth. The smaller mouth size caused an increase in malocclusion. This basically means dental alignment problems such as overbites and underbites. These problems have caused the creation of orthodontics. Since, the size of teeth is determined by genetics and the size of our jaws and muscles are determined by environmental factors, they have not stayed in proportion with one another. In other words the many problems we have with our teeth can be directly associated with the softer foods created by agriculture. Softer foods led to a smaller jaw size while the size of the teeth stayed the same. This directly caused the overcrowding such as the necessary removal of our wisdom teeth. Other problems that this has led to are: jaw misalignment, crooked teeth, and chewing problems.

Agriculture has also led to an increase in injuries which led to an increase of infections. This increase was caused by crowded settlements. “Anthropologists find, however, a general increase in periosteal reactions on the limb bones of skeletons from crowded settings in the Holocene.” A periosteal reaction is the inflammatory response of a bone’s covering most likely caused by infection of trauma.

Height also had a definite decrease after the advent of farming. This could have been a result of limited resources or perhaps an increase in stress. Being smaller, however, was not an indication of being healthier. In fact, evidence seems to point the opposite way. Many populations who had decreased height also had a higher tendency to have infectious disease, malnutrition, and anemia. Regardless of the cause, it is clear that people simply stopped growing as tall as they had been.

Agriculture has played an important role in the development of the human race. Unfortunately, it has had many negative effects on us along with the good such as poor health. For the advancement of human evolution, though, the advent of agriculture was a necessary evil and we would not be where we are today without it.

Sources:

http://www4.gvsu.edu/coler/GPY235/Readings/CivilizationsCostTheDeclineAndFallOfHumanHealthSCIENCE1May2009.pdf

Our Origins, by Clark Spencer Larsen

Wednesday, November 10, 2010

Agriculture: The Origin of Human Conflict

The advent of agriculture drastically changed the way that humanity lived on the face of the Earth. It created more stable groups, allowed for increased lifespan, and increased the population. However, the advent of agriculture had negative effects as well; it can be linked to the rise of human conflict and in extension a newfound mechanism of human death.

The advent of agriculture switched the lifestyle of early humans from nomadic to static. Originally humans constantly moved to find food, but with the rise of agriculture they were forced to settle down to control the growth of their crops. Agriculture’s potential for supporting large numbers of people living in a concentrated setting, and its potential for creating surplus and thus wealth for some, laid the foundation for the great civilizations of the past. In other words, the beginning of agriculture increased population while allowing for the first notions of group wealth. This concept of wealth and a rising population lead to a rise in the scale of conflict beyond anything that had been seen before.

Agriculture created the first complex societies. Domestication fueled humans’ population growth in the Holocene, and it formed the foundation for the rise of complex societies, cities, and increasingly sophisticated technology. With domesticated plants and animals people started living in larger and larger groups. With a reliable food source people were no longer starving and had much more stable food supply. This increased the chances of survival of all members of a group. This greater survival led to greater numbers.

Food, however, was still the most important commodity for early humans. As groups increased in size the need for larger food supplies rose. The amount of land and resources that could originally sustain a population was no longer adequate for the constantly increasing demands. Early humans had no choice but to expand. Land was the way to obtain more amounts of food. Farms had to be extended. Neighboring groups soon came into conflicts as territories encroached upon one another. Eventually conflicts began to erupt more and more frequently. These fights were fought with the lives of those in the society and so maintaining a large group of people became increasingly paramount. The only way to maintain such a large group was through increasing agriculture which became synonymous with increasing amounts of land. To expand demanded more people which demanded more land which cyclically demanded more land. Agriculture and the land became the key to survival. Land became the essence of wealth.

Because of this inherent need to continue acquiring land, conflict between different populations broke out. With the continued acquisition of land, settlements grew into each other and the struggle to control more resources began. With the increased population pressure continuously demanding greater amounts of food, a society’s ability to control more and more land became paramount for survival. Because of this conflicting struggle for resources, the rise of agriculture can be said to have directly brought about the rise of organized warfare between the earliest human societies. While agriculture is often fairly credited for forming the basis upon which sizeable human congregation and urbanization began, it can also be credited for creating the environment upon which human conflict originated. While agriculture can still be said to have played a significantly positive role in the advancement of human evolution, it can also be said to have provided the mechanism upon which millions of people would be killed throughout the course of human history.

Sources:

http://www.questionswithanswer.com/what/what_were_the_changes_brought_by_the_agricultural_revolution.html

http://bss.sfsu.edu/mwilliams/hist110/lectures/hist110L1.pdf

http://www.ncbi.nlm.nih.gov/pubmed/16463113

Wednesday, October 27, 2010

Agriculture's Impact on Human Population Growth

When walking into a supermarket, we can choose from a variety of foods and flavors to stimulate our taste buds. In fact, we are so spoiled that we can even decide which brand of a certain product we prefer. Unfortunately, humanity has not always been so lucky. Our population began small and grew very gradually for a long time. The advent of agriculture allowed for this growth in population. Around 10,000 years ago humanity switched from hunter gathering to farming. They began domesticating plants and animals to have a more stable food source. This change allowed for many significant changes in the way humanity existed on this planet. Most notably, agriculture has caused a rapid increase in the size of our population.

Around 10000 years ago, before the shift to agriculture, our population consisted of about only 2 or 3 million individuals. 2000 years ago, however, our population had grown staggeringly to 250 million. Today our population exceeds 6 billion. Technology and improvements in health care are partly responsible for this drastic change, but humanity’s switch to agriculture started this major change.

The effect of the agricultural revolution on human population growth is represented by the following graph:

The switch to agriculture was brought on by necessity and not chance. The human population had stagnated due to a lack of food. Domestication solved this problem. Farming and raising animals produced more food in a smaller space then did hunting and gathering. Wild animals roamed and edible plant life could never be guaranteed. When domestication began food sources stayed near the population. Rather than having to constantly relocate for food, groups could survive with a supply of food near at hand. Also, farming allowed for food to be stored and used at later times if alternative food sources ran short. These factors would allow for our population size to increase dramatically.

The stable supply of food allowed for early humans to have a greater chance of survival due to be more fully nourished. The roaming groups became more settled. This meant that a community could develop and such a society would eventually begin to protect one another from starvation and the wild. Being settled meant a group could learn one area and grow familiar with it rather than having to be constantly on alert. This comfort with the environment would allow people to live longer lives in less relative danger.

A growth in agriculture was necessary to allow the population to continue growing. Instead of random circumstances creating a single case in which agriculture appeared and then spread, evidence shows that agriculture began to pop up in many places around the world. Plant domestication, at least, started in around ten separate areas. This shows how it was a necessary adaptation by humanity to continue population growth.

It is clear that the development of agriculture has allowed for the human species to become what it is today. The attainment of a reliable and consistent food source allowed for the increased population growth of our ancestors. This increase in population allowed for the evolution of human beings to take an interesting turn; with a newfound element of stability, the sophistication of technology, health care, and culture became possible.

Sources:

http://www.springerlink.com/content/m12v36v06608277g/

Our Origins, by Clark Spencer Larsen

Wednesday, October 6, 2010

Climate, Agriculture, & Evolution

The evolution of human beings has been a long process that has gotten us to where we are today. Humans of today have evolved greatly from our ancestors, from hunting, to tools, to planting, to medicines, to machines, to rapidly growing technology, and it continues on. Around 10,000-13,000 years ago, our ancestors underwent a major change in life style and behavior. The transition from being hunter-gatherers to farmers was a huge step in history and has caused many changes in health, habits, way of living, and medicine. This development in human history has been called the Neolithic Revolution were humans learned to domesticate animals, cultivate crops, and build tools (historyworld). Scientists explain this phenomenon due to the change in climate. Around 15,000 years ago, the last Ice Age ended; thus causing more abundant plants to grow (AMBIO). This serge in plant life lead to annual plants to cycle seasonally, leaving dormant seeds. With the right soil, seeds, and weather, hunter-gatherers liked the idea of settling down and farming emerged.

The climate change also created specialization of certain crops in certain geographical locations. For example, these crops are very popular to produce in a special place; maize in Mexico, potatoes in the Andes, and rice from the banks of the Yangtze River (AMBIO). Since then, the processes and systems of agricultural procedures have advanced over time to be more efficient and abundant.

Not only did the climate boom the start of agricultural practices, but still today and in the future, the climate will continue to affect farming. The challenges we have had to face and continue to face include; increasing temperature, changes in environment conditions, and photoperiod… all of which affect plant life (Slater). Photoperiod means the duration of an organism's daily exposure to light, considered especially with regard to the effect of the exposure on growth and development (dictionary).

Basically, humans will need to proceed adapting to the changes of the climate. Like in the Neolithic Revolution, humans could live more comfortably because of the new temperate regions that were created. But, the animals that hunter-gatherers prayed on could not adjust to the new climates and had to move to cooler regions (historyworld). For example, the bison and mammoths (which became extinct due to the climate change) moved away while the humans adapted to the temperate zone and stayed there. Also in the temperate zone, plants grew easily. The humans decided to band the hunting of the few bison around and stuck to putting in the time to cultivate food and adapted to the new way of life.

Even though in reality hunter-gatherers had better health compared to when cultivation first began, agriculture has changed the lives of humans. Agriculture has evolved and will keep changing through out time due to the ever-changing climate. From the Ice Age, to temperate regions, to the theory of global warming, farmers today have to keep up with whatever climate is thrown at them to produce food. “Climate change is likely to increase the unreliability of farming systems”(Slater). But this statement is untrue, as humans have proven to adapt and make any changes to technology and procedures to continue improving and producing food that sustains the populations’ food supply.

Sources:

AMBIO: A Journal of the Human Environment 37(sp14):498-501. 2008. http://www.bioone.org/doi/full/10.1579/0044-7447-37.sp14.498.

Slater, Rachel. Climate Change: Implications for DFID’s Agriculture Policy. March 2008.

http://www.historyworld.net/wrldhis/PlainTextHistories.asp?historyid=ab63

http://www.thefreedictionary.com/photoperiod

Wednesday, September 22, 2010

Agriculture: A Killer for Thousands of Years

Roughly 10,000 years ago humankind went through a large transition that has forever changed the way that we all live. Our hunter-gatherer relatives began to domesticate animals and cultivate crops. A person with little knowledge of anthropology and human evolution such as I may think that this was a great, only positive advancement in the evolution of human behavior, but I have now uncovered that this advancement has its positives and negatives. It has allowed human populations to increase dramatically (a positive), but also it has exposed the human race to many diseases and hardships.

Today in every large city because of the living proximity of all the people disease and sickness spread quite easily. The same happened in ancient villages. The farming of plants and domestication of animals encouraged people to live closely. Infectious microorganisms went rampant with so many places for it to infect and disease outbreaks were very common. Ancient people had not built up defenses to these “new” diseases exposed to them. This fact lead to mass plagues and many deaths along the way. The same fact happens to the world today. For example, once Avion Flu (HPAI) finds a way to infect humans all of human will be in a compromised state because all of our bodies have not put up proper defenses against this epidemic. Farming and domestication of animals has in the past posed a threat to humans and it still does in this day and age.

Our hunter-gatherer relatives were a much healthier person than the agricultural breed. As I mentioned infections was much more rampant in the farming communities. Oral health such as tooth decay and enamel defects in hunter-gatherers was much less than their counter parts. Agriculturists did not replace the iron that many of the hunters of the past received by eating animals. Plants were much easier to produce and prepare than living creatures. Many people a result of this iron shortage became anemic because of the lack of iron in their diets. Humans had to compensate for these shortcomings in their diet so they evolved. New alleles formed to allow humans to properly digest the foods that they now relied on. A gene was now formulated through mutation that allowed the modern human to digest milk and get all of the valuable nutrients contained in it known as LCT. Even though humans in the beginning of this “Agricultural Revolution” struggled to stay as healthy as they once did as hunter-gatherers they all eventually adapted to their new environment and began to prosper.

My high school calculus teacher continually preached to us the mantra “Champions Adjust.” I now have come to realize that he truly taught across curriculums because throughout history humans are the champions. No matter what problems they encounter they always adjust.  The first they encountered was the difficulty to catch their food and find sufficient plants for their diets, so they began farming and the domestication of animals. The next problem they encountered and we still encounter today is the spread of diseases in high populated environments so they adjusted and developed immunities to these common diseases. In the future new foods will be produced and humans will find a way to eat them. The genotypes and phenotypes of humans together have allowed humans to continually advance to their respective environments and food supplies. Though agriculture has lent its fair share of problems to humans throughout the years humans have overcome these disadvantages and have become one of the most versatile and successful (in terms of survival) species on this earth.

For more information go to:

http://www.scientificamerican.com/article.cfm?id=culture-speeds-up-human-evolution

http://facstaff.unca.edu/cnicolay/cluster/disease-evol.pdf