Thursday, April 17, 2014

"A Brief Review of the Archaeological Evidence for Palaeolithic and Neolithic Subsistence"


The skeleton of a Neolithic woman in present-day Bulgaria.
Richard's text A Brief Review of the Archaeological Evidence for Palaeolithic and Neolithic Subsistence aims to reconstruct past Palaeolithic and Neolithic diets by analyzing the three lines of evidence that describe these diets. Evidence revolves around studying the morphological adaptations that our hominid ancestors developed, analyzing the material archaeological record, and observing direct evidence from carbon isotope analysis. Two morphological traits that Richard focuses on are the gracilization of the mandible and other cranial features, and an increase in cranial capacity; moreover, these adaptations provide evidence that there was an increased consumption of meat that continued throughout the Homo line. Organic plant remains rarely survive, whereas stone tools and faunal remains are more likely to survive and can indicate what our past ancestors may have eaten. However, these artifacts and animal remains do not give us an extensive and accurate description of the prehistoric human’s daily dietary intake, as these sites may have just been reserved for special and occasional feasts. Lastly, the stable isotope analysis provides detailed and accurate evidence on past diets, and the evidence concluded that meat and animal products were a huge part of the Neanderthal and modern human diet.

There was significant change in the archaeological record during the Neolithic period. Pottery, new grinding tools, and an increase in plant remains all provide evidence for plant and animal domestication during this time. Morphological features began to change as the Homo line adapted smaller body statures, decreased dentition size, and an increase in dental caries. The decrease in dentition and increase in dental caries are a direct result from the appearance of easier to chew and carbohydrate-rich processed foods. Neolithic human remains can also provide evidence for Neolithic diets, as changes in female skeletal remains show signs of grinding tasks and adds to the evidence that their diet consisted of grounded, processed food. The decrease of human health was merely a trade-off that humans made, as the adoption of agriculture provided enough food to increase population size and establish permanent settlements.

Sources:
  1. Richards, MP. 2002. A Brief Review of the Archaeological Evidence for Palaeolithic and Neolithic Subsistence. European Journal of Clinical Nutrition, 56: 1-9. 
  2. Image Source on itechpost.com

      Wednesday, April 16, 2014

      "The Story of the Human Body: Evolution, Health, and Disease"

      The cover of Lieberman's text.
      Daniel Lieberman, a Harvard palaeoanthropologist, wrote this book in order to analyze how the gradual transition to agriculture impacted the lifestyle of modern humans. I chose to post about this book because he focuses on the differences in hunter-gatherer and agriculturalist lifestyles, and he specifically analyzes how the transition to agriculture resulted in the promotion of various diseases that were not present in hunter-gatherer societies.

      Daniel Lieberman’s The Story of the Human Body: Evolution, Health, and Disease focuses on appearance of chronic “mismatched” diseases in modern humans, which is a result of cultural and biological evolution. Examples of mismatched diseases include diabetes, cancer, osteoporosis, obesity, cardiovascular diseases, etc. In order to better understand the origins of these mismatched diseases, it is important that Lieberman analyze the overall health and diet of modern humans and juxtapose it with that of our Palaeolithic ancestors. Modern humans are maladapted to a westernized diet of processed, synthetic foods. Lieberman asserts that the promotion of these chronic diseases would be reduced if humans reverted to a Palaeolithic lifestyle, which includes engaging in frequent physical activities and adapting a hunter-gather diet. Lieberman’s assertion relies heavily on the reconstruction and analysis of the Palaeolithic diet. Lieberman's text is split into three parts: 1. An extensive history on human evolution aimed to analyze human adaptations and natural selection, 2. The positive and negative effects that the Agricultural and Industrial Revolutions had on human evolution, and 3. How this information can be used to treat preventable illnesses in humans in the present and future. The first two parts of the text cover topics presented in this blog, as Lieberman compares and contrasts life before and after the rise of the Agricultural and Industrial revolutions.

      In order to demonstrate how modern humans became maladapted to their present day environments, which in turn increased their susceptibility to rare and previously unknown diseases when compared to their Paleolithic predecessors, one has to understand how humans evolved throughout time. By observing the earliest hominid species onwards, Lieberman analyzes the five major biological transitions in hominids relative to when they first appeared. The first transition is habitual bipedalism, and with bipedalism came various human adaptations such as hip shape, S-shaped spine, etc. Bipedalism was selected “to help the first hominins forage and obtain food more effectively in the face of major climate change that was occurring when the human and chimpanzee lineages diverged” (Lieberman 50). Bipedalism affected not only posture but dietary intake as well, and it allowed hominids to save energy while traveling farther than other quadruped or occasionally bipedal primates. Bipedalism led hominids to new food sources, which dramatically impacted dentition shape and strength. Dental adaptations reflected the importance of specific types of diets such as frugivory, omnivory, etc. Humans evolved to run, as archaic humans frequently engaged in persistence hunting which allowed them to utilize their intelligence and athleticism to become hunter-gatherers. Reliance on hunting large, fast prey resulted in an upgrade in weaponry, and their energy-filled hunter-gatherer diets led to an increase in brain size. By increasing brain size, humans prolonged their life history periods and added a stage of childhood, which is uniquely human. Archaic humans also had to gather and consume more calories in order to maintain their larger brains, slower developing bodies, and dependent offspring. Finally, archaic humans gained language, cooperation, and culture, which resulted in a new form of evolution: cultural evolution.

      Two other crucial transitions that were not a product of biological evolution but rather cultural evolution included the rise of the Agricultural and Industrial Revolutions, which dramatically altered the environment and therefore the human body. Cultural adaptability allowed hunter-gatherers to thrive in various environments, but it also reduced and eventually eradicated the need for hunting and gathering altogether. Cultural evolution “has not only driven but sometimes even accelerated selection” (Lieberman 186). The agricultural revolution gave rise to evolutionary mismatches, where a particular species is maladapted in a particular environment. In this case, it describes how humans evolved specific adaptations from bipedalism, varied diet, etc., that do not work well with their constantly changing environments. Now that hunter-gatherers settled down and began domesticating plants and animals, their environments have tremendously changed as farmers began to permanently settle in a single location. These settlements promoted an increase in population density, as farmers cultivated enough food to sustain larger families than hunter-gatherers. However, these communities lacked proper sanitation; as a result, these living conditions gave birth to various diseases and plagues. Although farming generated a surplus of food, farmers would engage in trade, which allowed them to spread bacteria and microbes that provoked diseases onto other communities. Trading allowed for diseases to quickly spread and infect other communities at different and farther locations. Living in close proximity to livestock also exposed humans to infectious disease. Agricultural diets lacked variety, which resulted in numerous mismatched diseases such as nutrient deficiencies. “Relying heavily on a few crops . . . has other serious disadvantages, the biggest being the potential for periodic food shortages and famine” (Lieberman 220). Compared to hunting and gathering, farming was much more laborious and risky as farmers could potentially starve if their crops should fail to grow. With farming came potential starvation, which is something that hunter-gatherers never had to experience. Because hunter-gatherers lived in groups with low population densities, they cooperated with one another and shared their hunt to ensure that they and their families would not starve.

      Although not central to this blog, the Industrial Revolution section of the text is still somewhat relevant, as this revolution could not have occurred without the establishment of agriculture. The Industrial Era was at first extremely demanding and laborious, but machines eventually ended up replacing manual human labor. Food could be cheaply processed by factories in large quantities, which created an abundance of foods high in fat, starch, sugar, and salt that were affordable to humans. Humans used to hunt and gather just enough food so they could have energy to last them until the next hunt; however, just as the agricultural revolution provided farmers with surplus of food, the Industrial Revolution produced food so cheaply that humans now have an excess of food, and their bodies did not evolve to handle this amount of energy. Food was now extremely modified and processed to evoke desirability from the masses, while the actual nutritious quality was deteriorating to low nutritional levels. Industrialization had trade offs where sanitation and producing food was improved while nutritional levels of the food plummeted. Food also became so processed and soft that it reduced the intensity of chewing. Bipedalism freed hunter-gatherers’ hands, which allowed for them to dig for food. Moreover, they would often feast on tough underground storage organs (USOs) required them to spend hours upon hours chewing since the USOs had strong, thick outer shells Once cultural evolution gave rise to the agricultural and Industrial revolutions, humans began to consume foods that are much more softer and mushier, which causes the teeth and jaw to become underused. The sugary processed foods also cause cavities, which is another problem that hunter-gatherers had never experienced before since their diets did not heavily consist of sugar. The Agricultural and Industrial Revolutions dramatically changed the way humans behaved, ate, and lived; therefore, it dramatically changed their bodies and their susceptibility to various mismatched diseases.

      Overall, Lieberman emphasizes that humans are still evolving and will continue to evolve through cultural evolution. By looking into our ancestors’ past, we can observe how hominids adapted to their environments and which trade-offs occurred with the rise of the Agricultural and Industrial revolutions. By using hunter-gatherers as an example, we can apply this knowledge to prevent the various mismatched diseases that modern humans experience in the present and future. Instead of treating the symptoms of a disease for a quick fix, Lieberman presses that it is the cause of the diseases that should be addressed in order to thoroughly prevent them. Mismatched diseases occurred as humans began to evolve culturally, and various other mismatched diseases are bound to come into existence as long as humans culturally evolve. As long as mismatched diseases are around, it is best to utilize the knowledge that we have on human evolution (which includes knowledge of how the transition to agriculture affected humans) and apply it to our treatment of these diseases.

      Sources:

      1. Lieberman, Daniel E. (2013). The Story of the Human Body: Evolution, Health, and Disease. New York, NY, USA: Pantheon.

      Friday, April 4, 2014

      Facts About the Agricultural Revolution

      1. The Neolithic revolution was actually a gradual event. It probably developed from the practice that some hunter-gathering societies have of encouraging their favorite plants to grow by clearing away competing plants (weeding or burning) and saving the seeds and planting them.
      2. The shift from hunting & gathering to agriculture led to permanent settlements, the establishment of social classes, and the eventual rise of civilizations.
      3. Neolithic villages continued to divide work between men and women.  However, women's status declined as men took the lead in in most areas of these early societies.
      4. Why did the establishment of agriculture prevail over hunting and gathering? Agricultural societies simply fed more people, allowed for larger families and so could push out, absorb or slaughter the hunter-gathering societies in the long run.
      5. While no one knows for certain what conditions caused the shift from hunting and gathering to sedentary agriculture, changes in the climate may have been significant factors. It is also probable that increases in human population prompted changes in food production.
      6. The first plants domesticated were the wild grains - barley and wheat - that were common in many regions of the Middle East.
      7. Sheep, goats, and pigs were among the first animals domesticated around 8500 B.C.E. Cattle, more aggressive and faster than the other animals, were added to the agricultural system around 6500 B.C.E. 
      8. The development of sedentary settlements accelerated the pace of technological development. Many of these innovations were directly connected to agriculture, including plows, implements, techniques of seed selection, and irrigation. The development of better tools led to better housing and systems for the storage of grain.
      9. The production of food surpluses allowed social differentiation and economic specialization. Some people were freed from the processes associated with the production of food to make other commodities, such as cloth, pottery, and leather goods. Economic specialization led to social stratification and the creation of elite classes of rulers.
      10. The favorite settlement locations were river basins and flood plains. These areas could be relied upon to bring regular floods for the irrigation of crops. 
      11. However, Neolithic societies were noticeably more hierarchical than the Paleolithic cultures that preceded them and hunter-gatherer cultures in general.
      12. Families and households were still largely independent economically, and the household was probably the center of life
      13. A significant and far-reaching shift in human subsistence and lifestyle was to be brought about in areas where crop farming and cultivation were first developed: the previous reliance on an essentially nomadic hunter-gatherer subsistence technique or pastoral transhumance was at first supplemented, and then increasingly replaced by, a reliance upon the foods produced from cultivated lands.
      14. Neolithic peoples were skilled farmers, manufacturing a range of tools necessary for the tending, harvesting and processing of crops (such as sickle blades and grinding stones) and food production (e.g. pottery, bone implements). They were also skilled manufacturers of a range of other types of stone tools and ornaments, including projectile points, beads, and statuettes.
      Sources:

      Comparing Lifestyles

      Caveman comic by Baloo!
      This is the go-to post to identify the pros and cons of the hunting-gathering and agricultural lifestyles. I have taken the advantages and disadvantages from my previous posts and other websites (which will be cited below) and compiled them all into one list. If you would like to contribute, please comment below and I will update the list. Thank you!

      Hunters and Gatherers:

      Advantages:
      • Nutritional quality of food was high; high in fiber, plant sterols, and vegetable proteins. (Source #4)
      • Constant physical activity good for hunter-gatherers' health; obtained vitamin D through sun exposure. (Source #4)
      • Evidence that a Palaeolithic diet promotes low levels of systolic blood pressure, weight, and BMI. (Source #4)
      • Energy-filled hunter-gatherer diets led to an increase in brain size. (Source #3)
      • Increase in brain size prolonged life history periods and added a stage of childhood. (Source #3)
      • Hunter-gatherers lived in groups with low population densities; they cooperated with one another and shared their hunt. (Source #3)
      • Consuming sweet foods beneficial to survival. (Source #5)
      • Exploited as many resources as possible instead of relying on a few. (Source #6)
      • Large, communal knowledge of their range and the food sources, dangers, and opportunities which exist within it. (Source #6)
      Disadvantages:
      • Unreliable food supply. (Source #1)
      • Main occupation was hunting for food; left no free time to refine skills. (Source #1)
      • Must gather and consume more calories in order to maintain their larger brains, slower developing bodies, and dependent offspring. (Source #3)
      • Low child-to-adult ratios. (Source #6)
      • Privacy is nonexistent. (Source #6)

      Agriculturalists:

      Advantages:
      • Controllable and reliable food supply. (Source #1)
      • Supports growth of human populations. (Source #2 and 3)
      • Food surpluses; feasting leads to social networking. 
      • Development of larger, stratified societies. (Source #2) 
      • Can be practiced all over the world.
      • New occupations (sewing, building, etc); refining skills. Specialization in work othe than agriculture resulted in new occupations and technologies. (Source #1)
      • Allowed trade to occur between different groups.(Source #1 and 3)
      • Pastoralism and agriculture become mutually dependent. (Source #6)
      • Pastoralism: Use animals to transport resources. (Source #1)
      • Pastoralism: Breeding animals for consumption, resources, etc. (Source #1)
      • Organized warfare emerged and became common; this can be both an advantage and disadvantage. (Source #6)
      Disadvantages:
      • Nutritional quality of food decreases; enriched in high glycemic index carbohydrate sources, animal products, meat, saturated fat, and cholesterol.(Source #4)
      • Requires more effort and energy in order to plant, tend, and harvest crops.
      • Must radically change the environment of the planet; consequences such as deforestation, erosion, flooding, desertification, etc. (Source # 3)
      • Greater dependence on a smaller variety of food. (Source #6)
      • Cause of inequality, famine, overpopulation, materialism, etc. (Source #3)
      • Communities lacked proper sanitation which resulted in the promotion of diseases and plagues. (Source #3)
      • According to Daniel Lieberman, the effects of agriculture and rise in technology promoted the appearance of "mismatched diseases" such as cancer, diabetes, cardiovascular diseases, obesity, osteoporosis, rickets, etc. (Source #3 and 5)
      • Trade among agriculturalists spread bacteria and microbes that provoked diseases onto other communities. (Source #3)
      • Agriculturalists are prone to height reduction, shorter lifespan, higher child mortality rate. (Source #3)
      • Consuming sweet foods detrimental to survival; sweets are superabundant and deteriorate health. (Source #5)
      • Greater vulnerability to weather. (Source #6)
      Please comment if I left out a particular advantage/disadvantage!

      Tuesday, April 1, 2014

      Neolithic Artifacts

      Many believe that the origins of agriculture began in the Neolithic era, thus claiming it as "The Neolithic Revolution". However, the origins of agriculture was gradual and began in many different areas at different times. Depicted below are some interesting artifacts that were used by cultivators and agriculturalists during the Neolithic era. 

      An array of Neolithic artifacts, including bracelets, axe heads, chisels, and polishing tools. Neolithic stone implements are by definition polished and, except for specialty items, not chipped.

      A Cucuteni-Trypillian culture deer antler plough.

      Food and cooking items retrieved at a European Neolithic site: millstones, charred bread, grains and small apples, a clay cooking pot, and containers made of antlers and wood.

      Polished Neolithic jadeitite axe from the Museum of Toulouse.
      From Wikipedia: "During the Neolithic period, large axes were made from flint nodules by chipping a rough shape, a so-called "rough-out". Such products were traded across a wide area. The rough-outs were then polished to give the surface a fine finish to create the axe head. Polishing not only increased the final strength of the product but also meant that the head could penetrate wood more easily.


      Such axe heads were needed in large numbers for forest clearance and the establishment of settlements and farmsteads, a characteristic of the Neolithic period. There were many sources of supply, including Grimes Graves in Suffolk, Cissbury in Sussex and Spiennes near Mons in Belgium to mention but a few. In Britain, there were numerous small quarries in downland areas where flint was removed for local use, for example."

      Source:
      1. Neolithic Artifacts on Wikipedia