Human settlements in Amazonia much older than previously thought

Human settlements in Amazonia much older than previously thought
Excavations at the site of La Chacra. Credit: José Capriles, PSU

Humans settled in southwestern Amazonia and even experimented with agriculture much earlier than previously thought, according to an international team of researchers.

"We have long been aware that complex societies emerged in Llanos de Moxos in southwestern Amazonia, Bolivia, around 2,500 years ago, but our new evidence suggests that humans first settled in the region up to 10,000 years ago during the early Holocene period," said Jose Capriles, assistant professor of anthropology. "These groups of people were hunter gatherers; however, our data show that they were beginning to deplete their local resources and establish territorial behaviors, perhaps driving them to begin domesticating plants such as sweet potatoes, cassava, peanuts and chili peppers as a way to acquire food."

The conducted its study on three forest islands—Isla del Tesoro, La Chacra and San Pablo—within the seasonally flooded savanna of the Llanos de Moxos in northern Bolivia.

"These islands are elevated above the surrounding savanna, so they do not flood during the ," said Capriles. "We believe people were using these sites recurrently as seasonal camps, particularly during the long rainy seasons when most of the Llanos de Moxos become flooded."

Human settlements in Amazonia much older than previously thought
Excavation team taking measurements during excavations. Credit: José Capriles, PSU

The team's excavations of the forest islands revealed human skeletons that had been intentionally buried in a manner unlike that of typical hunter gatherers and instead were more akin to the behaviors of complex societies—characterized by political hierarchy and the production of food. Their results appear today in Science Advances.

"If these were highly mobile you would not expect for them to bury their dead in specific places; instead, they would leave their dead wherever they died," said Capriles.

Capriles noted that it is rare to find human or even that predate the use of fired pottery in the region.

"The soils tend to be very acidic, which often makes the preservation of organic remains very poor," he said. "Also, deteriorates quickly in tropical environments and this region completely lacks any type of rock for making stone tools, so even those are not available to study."

  • Human settlements in Amazonia much older than previously thought
    Samples collected from the excavation site. Credit: José Capriles, PSU
  • Human settlements in Amazonia much older than previously thought
    Collection of sedimentary cores in the forest island San Pablo, in the picture, Dr. Umberto Lombardo. Credit: José Capriles, PSU
  • Human settlements in Amazonia much older than previously thought
    Human burials exposed and recovered during the archaeological excavations at the forest island of La Chacra during excavations. Credit: José Capriles, PSU
  • Human settlements in Amazonia much older than previously thought
    Burial in La Chacra exposed during archaeological excavations. Credit: José Capriles, PSU

According to Umberto Lombardo, earth scientist at the University of Bern, when the researchers first published their discovery of these archaeological sites in 2013, they had to base their conclusions on indirect evidence—mostly geochemical analyses—rather than direct evidence such as artifacts.

"Because of the lack of direct evidence many archaeologists were skeptical about our findings," said Lombardo. "They did not really believe that those forest islands were early Holocene archaeological sites. The current study provides strong and definitive evidence of the anthropocentric origin of these sites, because the archaeological excavations uncovered early Holocene human burials. These are the definitive proof of the antiquity and origin of these sites."

Capriles noted that the on these forest islands were preserved despite the poor conditions because they were encased within middens—or trash heaps—containing abundant fragments of shell, animal bones and other organic remains.

"These people were foraging apple snails during the wet season and disposing of the shells in large heaps, called middens," said Capriles. "Over time, water dissolved the calcium carbonate from the shells and those carbonates precipitated over the bones, effectively fossilizing them."

Human settlements in Amazonia much older than previously thought
Mapping during the archaeological excavations at the site of La Chacra. Credit: José Capriles, PSU

Because the human bones were fossilized, the team was unable to date them directly using radiocarbon dating. Instead, they used of associated charcoal and shell as a proxy for estimating the time range that the sites were occupied.

"The abundant remains of burned earth and wood suggests that the people were using fire, likely to clear land, cook food and keep warm during long rainy days," said Capriles.

According to Capriles, a gap exists between the people his team studied who lived on the forest islands between 10,000 and 4,000 years ago and the rise of complex societies, which began around 2,500 years ago.

"This paper represents the first step in the effort to learn more about the people who inhabited southwestern Amazonia for thousands of years but we know nothing about," said Lombardo.

Capriles added, "Are the people we found direct predecessors of those later, more complex societies? There are still questions to be answered and we hope to do so in future research."


Explore further

Rise of religion pre-dates Incas at Lake Titicaca

More information: J.M. Capriles at Pennsylvania State University in State College, PA el al., "Persistent Early to Middle Holocene tropical foraging in southwestern Amazonia," Science Advances (2019). advances.sciencemag.org/content/5/4/eaav5449
Journal information: Science Advances

Citation: Human settlements in Amazonia much older than previously thought (2019, April 24) retrieved 17 July 2019 from https://phys.org/news/2019-04-human-settlements-amazonia-older-previously.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
1318 shares

Feedback to editors

User comments

Apr 24, 2019
Shoutout Randall Carlson and Graham Hancock...

Apr 25, 2019
"These groups of people were hunter gatherers; however, our data show that they were beginning to deplete their local resources and establish territorial behaviors, perhaps driving them to begin domesticating plants such as sweet potatoes, cassava, peanuts and chili peppers as a way to acquire food."

Technology = overpopulation = tribalism = intertribal conflict = territory, agriculture, walled settlements, migration. Humans have been dealing with overgrowth ever since they became able to hunt the animals that were hunting them.

The very unnatural exigencies of tribal life is what created the domesticated human animal. And the very unnatural process of group selection among tribes is what drove the emergence of civilizations.

Apr 25, 2019
Shoutout Randall Carlson and Graham Hancock...


Please link to their peer reviewed papers on the subject. I'd be fascinated to read them.

Apr 25, 2019
These groups of people were hunter gatherers
This is a purely fact-free and very fallacious statement. The researchers have absolutely no way to substantiate it, other than sheer speculation.
We were created to be workers of the soil from day 6 and our original diet was purely plant based, right from the start - Gen 1:29.
Since humans (and ALL other biological lifeforms) did not (and could not) arise spontaneously, the Creator had already designed and provided food for all the living organisms - plants made on day 3.

Apr 25, 2019
These groups of people were hunter gatherers
This is a purely fact-free and very fallacious statement. The researchers have absolutely no way to substantiate it, other than sheer speculation.
We were created to be workers of the soil from day 6 and our original diet was purely plant based, right from the start - Gen 1:29.
Since humans (and ALL other biological lifeforms) did not (and could not) arise spontaneously, the Creator had already designed and provided food for all the living organisms - plants made on day 3.


Lol.

Apr 25, 2019
tribalism ... group selection


Just because you endlessly troll this unsubstantiated claim, it does not make it any more fact or interesting for others to read. It cannot be substantiated, since group selection has never been observed.

This is the 3d time or so, in about as many days, as you pet your pet theory - it is the same as trolling, when the evidence goes in the other direction - selfish gene selection has been observed many times (to say the least).

I will now block you for inane trolling, so don't bother respond. Group selection is not impossible, just very unlikely, and I will only lift the block (if I remember) the day someone publish robust, later repeated, peer reviewed data that show it happens.

Apr 25, 2019
I forgot: it would of course be all right to discuss "group selection" as such. But with the people (often ecologists) that propose it, validation never seem to matter. It becomes an empty, unlikely claim, as here.

Apr 26, 2019
@Castrogiovanni
Lol.
If you think that the biblical account is laughable, perhaps you should examine the alternative - the scientific impossibility of everything arising from nothing or life arising from non-living materials all by itself via random chemical and physical processes with no input from a powerful and intelligent outside agent. Scientists have been struggling for the past 70 years already trying to get past just the chirality problem, never mind the intelligence/information contained in the DNA structure.
Philosophically, the big bang theory is bust - there is no way for material to exist eternally and preserve energy in a useful state. Hence there has to be an immaterial, all powerful, eternal and intelligent agent that gave rise to everything we know. That is the only rational explanation. Anything else is irrational, including the big bang and billions of years paradigm.

Apr 29, 2019
Just because you endlessly troll this unsubstantiated claim, it does not make it any more fact or interesting for others to read. It cannot be substantiated, since group selection has never been observed
You're still trying to conflate the natural version of group selection which may or may not be occurring in nature, with the very artificial version which has been occurring among tribes for the last million years.

And I have repeatedly substantiated it with opinions from experts since Darwin and before. With this
http://rint.recht...rid2.htm

-as well as repeated historical examples which demonstrate quite clearly how groups - tribes - select for fitness for tribal life within the tribe, while selecting for fitness of tribes themselves in competition over resources.

Stop trying to equate the 2.

Academies do this to try to discredit the very real presence of tribalism in society. You apparently do it because you dont appreciate the distinction.

Apr 29, 2019
the scientific impossibility of everything arising from nothing or life arising from non-living materials all by itself via random chemical and physical processes with no input from a powerful and intelligent outside agent
Once again, someone needs to point out to fred that just declaring something is true doesnt make it so. Doesnt matter if the declarers are sitting in glorious buildings and wearing fancy robes.

Fred and his cohorts ignore the evidence in favor of declarations found in books full of verifiable lies. He and they ignore all reasoned argument and sound evidence because the books say that doubting them is a sin and will jeopardize their eternity in heaven.

This alone should make any intelligent person suspicious.

Apr 29, 2019
I will now block you for inane trolling, so don't bother respond
You already blocked me fred. You refuse to visit the rechten site I linked, and you refuse to consider the reality of tribalism while continuing to criticize me for the wrong reasons.

So who's the troll?

But then who gives a shit, really?

THE FIRST PARAGRAPH from that paper:

"Darwin (1871) considered the possibility of (violent) interGROUP competition in (early) hominid/human evolution in his tentative explanation of the evolution of morality and other specifically human qualities:
"There can be no doubt that a tribe including many members who, from possessing in a high degree the spirit of patriotism, fidelity, obedience, courage, and sympathy, were always ready to give aid to each other and to sacrifice themselves for the common good, would be victorious over most other tribes; and this would be natural SELECTION" (Darwin, 1871, i, p. 166; italics added)."

Apr 29, 2019
If you think that the biblical account is laughable,....


I do, and it is. Why would I care what a bunch of Bronze Age peasants dreamed up thousands of years ago? Why would anybody?

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more