Posted on 02/26/2019 12:01:55 PM PST by Oldeconomybuyer
A new study shows climate change may have contributed to the decline of Cahokia, a famed prehistoric city near present-day St. Louis. And it involves ancient human poop.
Published today [Feb. 25, 2019] in the Proceedings of the National Academy of Sciences, the study provides a direct link between changes in Cahokia’s population size as measured through a unique fecal record and environmental data showing evidence of drought and flood.
“The way of building population reconstructions usually involves archaeological data, which is separate from the data studied by climate scientists,” explains lead author AJ White, who completed the work as a graduate student at California State University, Long Beach. “One involves excavation and survey of archaeological remains and the other involves lake cores. We unite these two by looking at both kinds of data from the same lake cores.”
Last year, White and a team of collaborators - including his former advisor Lora Stevens, professor of paleoclimatology and paleolimnology at California State University, Long Beach, and University of Wisconsin–Madison Professor of Anthropology Sissel Schroeder - showed they could detect signatures of human poop in lake core sediments collected from Horseshoe Lake, not far from Cahokia’s famous mounds.
These signatures, called fecal stanols, are molecules produced in the human gut during digestion and eliminated in feces. As the people of Cahokia pooped on land, some of it would have run off into the lake. The more people who lived and defecated there, the more stanols evident in lake sediments.
Because the sediments of a lake accumulate in layers, they allow scientists to capture snapshots of time throughout the history of a region through sediment cores. Deeper layers form earlier than layers found higher up, and all of the material within a layer is roughly the same age.
White found that fecal stanol concentrations at Horseshoe Lake rise and fall similarly to estimates of Cahokia’s population from better-established archaeological methods.
Schroeder, a scholar of the Cahokia area, says that excavations of the houses in and near Cahokia show human occupation of the site intensified around A.D. 600, and by 1100, the six-square-mile city reached its peak population. At the time, tens of thousands of people called it home.
Archaeological evidence also shows that by 1200, Cahokia’s population was on the decline and the site was abandoned by its mound-building Mississippian inhabitants by 1400.
Scientists have uncovered a number of explanations for its eventual abandonment, including social and political unrest and environmental changes.
For instance, in 2015, co-author Samuel Munoz, a former UW–Madison graduate student and now a professor at Northeastern University, was actually the first to collect one of the Horseshoe Lake sediment cores White used in his study and he found evidence that the nearby Mississippi River flooded significantly around 1150.
White’s latest study ties the archaeological and environmental evidence together.
“When we use this fecal stanol method, we can make these comparisons to environmental conditions that hither to now we haven’t really been able to do,” says White, now a PhD student at UC Berkeley.
Using Munoz’s core and another White collected on Horseshoe Lake, the research team measured the relative amount of fecal stanols from humans present in sediment layers. They compared these to stanol levels known to come from bacteria in the soil in order to establish a baseline concentration for each layer.
They examined the lake cores for evidence of flooding and also looked for climate indicators that would inform them whether climate conditions were relatively wet or dry. These indicators, the ratio of a heavy form of oxygen to a light one, can show changes in evaporation and precipitation. Stevens explains that as water evaporates, the light form of oxygen goes with it, concentrating the heavy form.
The lake core showed that summer precipitation likely decreased around the onset of Cahokia’s decline. This could have affected the ability of people to grow their staple crop, maize.
A number of different changes begin to happen in the archaeological record around 1150, Schroeder explains, including the number and density of houses and the nature of craft production.
These are all indicators of “some kind of socio-political or economic stressors that stimulated a reorganization of some sort,” she says. “When we see correlations with climate, some archaeologists don’t think climate has anything to do with it, but it’s difficult to sustain that argument when the evidence of significant changes in the climate shows people are facing new challenges.”
This has resonance today, she adds.
“Cultures can be very resilient in the face of climate change but resilience doesn’t necessarily mean there is no change. There can be cultural reorganization or decisions to relocate or migrate,” Schroeder says. “We may see similar pressures today but fewer options to move.”
For White, the study highlights the nuances and complications common to so many cultures and shows how environmental change can contribute to social changes already at play.
so, San Francisco won’t be the first city destroyed by poop?
The ‘climate’ changed when a bunch of new guys moved in and killed them all .. climate problem solved
what, you didn’t find the pony ?
I guess they just explained roanoke.
They explained the 1930’s dust bowl.
It has to be true. Pooptrometers use to measure its characteristics are highly accurate.
I’m sure it had nothing to do with mass murder, especially of women, and enslavement of neighboring tribes.
Have they unvovered any SUVs yet?
‘Climate Change’ is a tautology (a redundancy) as the worlds climate HAS ALWAYS CHANGING
Leftists lie as easily as they breath, and dont give a damn about truth or honesty.
So for the unfortunates being bombarded by this leftist propaganda just remind THEM that : The same proponents of ‘climate change’ are the ones who pushed ‘Global Warming’ which has been shown to be a socialist scam (they had to change that scams name to be more vague - so that ANYTHING can be claimed to be ‘climate change’).
To the Leftards - demand that they : Turn off their air conditioning, and keep their heat at 65 in winter, and STOP driving their cars (use public transit) and stop going on trips -— Or THEY ARE HYPOCRITES (they CAN DO these things TODAY if they actually believe what they spew - but for some reason they never seem to)
“Archaeological evidence also shows that by 1200, Cahokia’s population was on the decline and the site was abandoned by its mound-building Mississippian inhabitants by 1400.”
So it took well over 200 years for the so called “fall”? Most civilizations don’t last that long!
“Scientists have uncovered a number of explanations for its eventual abandonment, including social and political unrest and environmental changes.”
But what’s in the headline? Climate change.
I too was thinking about the Medieval warm period coinciding with the time of ‘climate change’ mentioned in the article. A connection the author did not mention. I wonder if the archaeologists are taking that in account or just looking at Cahokia in isolation from the rest of global weather patterns and climatology?
We regret to inform your young archeologist group that their finding is not the petrified penis of a prehistoric prince but is the remainder of a creature that crept into the crypt and crapped.
“Cultures can be very resilient in the face of climate change “
unfortunately concentrated technologically-primitive populations are quite brittle when their food production is impacted by climate. The population has to disperse when the local crops are insufficient.
Example - Even in China, where civilization was extremely sophisticated, something like 1 million people DIED EVERY YEAR of Famine (even up to the time of the revolution) because their transportation was incapable of transporting sufficient food inter-regionally
That's not "climate change" that's just a "500 year flood," like 1993. The Mississippi has a long history of fairly regular multiyear flood cycles...not just the normal annual spring flooding.
Well played sir!
I had a suspicion about the Cahokia poopulation and their travels..
*um, ping*
Its also the case that the medieval warm coincides with the viking expansion out of Scandinavia. better climate more food more people so the extras go raiding and colonizing.
Its also the case that the medieval warm coincides with the viking expansion out of Scandinavia. better climate more food more people so the extras go raiding and colonizing.
This isn’t Goebbels stuff.
It is indisputable that the various climates which exist on our planet (there is no “global climate”) have undergone huge changes in historic time which have moved around, wiped out, or fostered various human populations.
Whether the activity of humans have had, or have now, anything to do with this is, of course, very dubious.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.