Tuesday, March 20, 2012

Human Created environmental Change- The Southeast

Mark J. Lynott, Thomas W. Boutton, James E. Price, Dwight E.
1986 Stable Carbon Isotopic Evidence for Maize Agriculture in Southeast Missouri and Northeast Arkansas
American Antiquity
Vol 51, No. 1 Pages 51-65

In Lynott, et. al’s article Stable Carbon Isotopic Evidence for Maize Agriculture in Southeast Missouri and Northeast Arkansas, it is concluded that populations after A.D. 1000 become dependent on maize as a significant source of sustenance. This article outlines how bones from fourteen sites in southeast Missouri and northeast Arkansas that ranged in age from 3200 B.C. to about A.D. 1880. were measured for the amount of Carbon-13 in the collagen of the bones. this is because the native plants are of a C3 photosynthetic pathway which means that they are depleted in Carbon-13 whereas Maize as a tropical grass is of a C4 photosynthetic pathway resulting in a more enriched state of Carbon-13. It was found in the data that samples after A.D. 1000 are higher in Carbon-13 indicating that the people were consuming significant amounts of Maize. the article goes on to say that since a large majority of native plants use the C3 pathway it is a fair assumption that the increase in Carbon-13 is a direct result of significant consumption of maize. Furthermore the article states that the change from non-significant consumption of maize to significant consumption of maize was very rapid. This evidence for significant maize consumption also means that emergent Mississippian communities in northeast Arkansas and southeast Missouri did not consume large amount of maize but rather that it was not until large settlements of sedentary people developed that maize horticulture was adopted. This article is important to the area of human created environmental change because it is providing evidence of when intensive maize agriculture began in parts of the southeast region. this is important because with the intensification of agriculture, especially with that of maize, large human caused changes occur such as the clearing of forests to make room for fields and irrigation, which changes the way in which water flows and the areas that water is present.

Joe W. Saunders, Rolfe D. Mandel, Roger T. Saucier, E. Thurman Allen, C. T. Hallmark, Jay K. Johnson, Edwin H. Jackson, Charles M. Allen, Gary L. Stringer, Douglas S. Frink, James K. Feathers, Stephen Williams, Kristen J. Gremillion, Malcolm F. Vidrine, Reca Jones
1997 A Mound Complex in Louisiana at 5400-5000 Years Before the Present
Science
Vol 277 NO 5333 pages 1796-1799

In Saunders, et al’s article A Mound Complex in Louisiana at 5400-5000 Years Before the Present, the Mound complex site of Watson Brake in Louisiana is claimed to predate that of Poverty Point’s earthworks by 1900 years. This means that Watson Brake would be the earliest human construction recognized so for in the New World. Watson Brake is a mound complex that contains 11 mounds with connecting ridges which form an oval-shaped earthen enclosure. the largest mound is 7.5 m in height while the other mounds measure between 1m and 4.5 m in height. Dates on Charcoal scatters indicate that construction of mounds at Watson Brake began between 5400 and 5300 years B.P. furthermore Artifactual data further supports a pre-Poverty Point origin for the Watson Brake site. Lithic material is of local gravel which is in contrast to the late archaic period of poverty point in which nonlocal lithic materials were common. Additionally remains of fish and non-domesticated plants suggest that the site was occupied seasonally. these plants include goosefoot, Knotweed, and possibly Marshelder which suggest the beginnings of the process that lead to domestication of these plants. The multiple methods of dating (including geomorphic, radiometric and luminescence) indicate that the site is of the Middle Archaic period, while the plant and animal remains indicate that Watson Brake was occupied seasonally by mobile hunter-gatherers (several other mounds in the southeast have been dated to the middle Archaic however Watson Brake is the most reliably dated site). This level of organized large earthworks was previously considered to be beyond the capabilities of seasonally mobile hunter-gatherers, with poverty point as the exception to this rule. This Article is important because it shows evidence for monumental architecture and the possible beginnings of domestication of the major domesticates of the eastern North American area both of which has great importance on the subject of human created environmental change.

2 comments:

  1. I find the first article to be extremely interesting. I had never heard of a photosynthetic pathway depriving or enriching the levels of C-13 in plants, and by extension human remains. I would be extremely curious to know if a similar difference in pathway could produce an enriched amount of C-14, thus changing the result of any radiometric dates on corn remains and the dating on things that ate these plants.
    I am extremely dubious about the second article. Any claim of 'first' should be approached with extreme caution; especially when the claimed 'first' is so complex in comparison to nothing. Although I have posted articles individually helping to pull out the flaws of each of the dating methods you cite, the fact that they align so nicely would suggest the dates are correct. Still, I would rerun the dating methods a number of times, as any archaeologist should realize the controversy such a claim would stir up.

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  2. The first article here seems to say something a little different from my Fritz and Kidder article. In the Fritz and Kidder article they are suggesting that maize domestication (and domestication in general) was not really that well established in the area. They argue that since there was a lot of human interaction with the environment in terms of earthen works and some complex society, archaeologists tend to assume there was domestication. Fritz and Kidder say that there was a little evidence of domesticated maize but not enough to say was domesticated in the area. In your article here, the authors seem to be stating what Fritz and Kidder say most archaeologists believe. It is interesting that you said they found “in the data that samples after A.D. 100 are higher in C-13 indicating that people were consuming significant amounts of maize.” I wonder if this was domesticated, cultivated, or foraged. I also wonder how much evidence the have to support this or if they are just assuming there is a lot of maize. I would be interested to learn more about this argument and see some raw data.

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