Ancient people of Colombia used collective labor to build a massive canal network that spans 2,000 square miles, a discovery that challenges the assumption that colossal works require top-down hierarchical social organization, reports a study published on Monday in Communications Sustainability.

From the first century BC to the 11th century, Colombian peoples living in the La Mojana  lowlands sculpted their wetland environment by building raised fields, ridges, and canals, which are today referred to as the Zenú hydraulic systems after the culture that built them. These multipurpose structures absorbed water during heavy rains and released it during dry seasons, creating a water management system that prevented both flooding and droughts. The vast network also provided water to communities for plant cultivation and access to fish.

For years, researchers have debated whether the immense work was built through top-down social organization at the direction of elite leaders, or if people could have collectively labored to construct it through bottom-up organization. 

Now, a team of scientists has used satellite imagery to map a 1,200-acre patch of the system in unprecedented detail. With that sample, they built a model to estimate the population and labor costs of construction in that area. Assuming that about 1,600 people inhabited this area and half of them were part of the workforce, the structures could have been built in under six weeks, about half the dry season, which is a low labor cost that would not have required top-down organization.

“La Mojana is a special case study, in that it is the first to demonstrate in concrete, quantitative terms that these massive works are compatible with bottom-up, community-driven organisation,” said Jasmine Vieri, a research associate at the McDonald Institute of Archaeological Research at the University of Cambridge who led the study, in an email with 404 Media. “But it is also part of a much broader paradigm shift in how archaeology interprets evidence for hierarchy or top-down power.” 

“As human beings, we tend to understand the world through our own lens, and many of us now live in hierarchical societies, where large-scale infrastructure, monumental architecture, or luxury goods are often commissioned by, or concentrated in the hands of a few,” she continued. 

“Archaeological evidence from other regions and periods keeps revealing cases where people came together to achieve ambitious, collective goals through cooperation rather than coercion.”

The team’s sample included roughly 1,600 ridges and 63 housing platforms, most of which were about 4.5-feet tall when they were initially constructed. Though the exact dates of construction are unclear, these systems were constructed before the emergence of metal tools, such as shovels, though they may have used wood tools. 

Based on this level of technology and workforce numbers, the team estimated that the largest raised ridge in the sample, which stretches for a third of a mile, would have taken a family of five months to complete, whereas a workforce of 800 could have built it in a matter of hours. But some of the smaller ridge structures could have been built by a single family over the course of a few days. The results suggest that the whole system in this sample could have been renewed once a generation, with just a few days of annual work.

“We entered the project with an open mind, although we did consider collective labour one feasible model from the start,” Vieri said. “However, when we did obtain the estimates, even we were surprised at how low they were, running through them several times just to confirm they were correct.”

The study was co-authored by Fernando Montejo Gaitán of the Colombian Institute of Anthropology and History, who has spent decades researching these ancient waterways and is part of REVERSEACTION, a project funded by the European Research Council focused on complex technologies in stateless societies. 

Understanding how these people built such massive works is not just a matter of reconstructing the past, it’s also an adaptation strategy for the future, according to the study.

“Instead of focusing on futile attempts at blocking water, policymakers should consider borrowing the pre-Hispanic solution of working with the inundation rather than against it,” Vieri said. “Modern dikes built by the Colombian government are intended to prevent seasonal flooding, but are often breached by high-volume currents, destroying human lives and livelihoods.” 

“In contrast, the pre-Hispanic raised fields functioned to redistribute the flow of water, enabling human settlement and cultivation above the water level throughout the wet season,” she continued. “Raised fields simultaneously buffer against severe droughts by storing and gradually releasing water during the drier months.”

For more than a millennium, people in this region used this strategy to go with the flow, without the need for top-down direction. Hopefully, future work might uncover more insights about the role of social organization in massive works, and the possibility that large structures might have emerged from small collectives.

“Answering these questions would contribute much to broader archaeological debates on the relationship between infrastructural scales and political organisation,” Vieri said. “In fact, a key outcome of our research is an open-source pipeline that can be readily be applied to the study of agricultural systems in other regions, enabling cross-comparative research into testing the strength of the evidence for bottom-up, multi-scalar, or top-down social organisation across different time periods or communities.” 

Research Gold, a site that advertises services for medical researchers, including drafting peer-review ready manuscripts, systemic reviews and meta-analyses, claims that it’s “100% human-written, never AI,” and lists a number of PhD reviewers and professional methodologists on staff that carry out this meticulous, difficult work.

The problem: The PhD reviewers Research Gold lists on its site are AI-generated and don’t exist. Other methodologists it lists are real, but are not aware their identity is being used by Research Gold. When I tried calling the company, an AI agent that refused to concede it was AI answered and kept trying to sell me Research Gold’s services. Email and chat communication with the company were also AI generated. 

“Protocol, search, screening, extraction, risk of bias, statistics, and a publish-ready manuscript formatted to your target journal or committee. Led by PhD methodologists with peer-reviewed publication records. PRISMA 2020 and Cochrane Handbook methodology. Authorship stays with you,” Research Gold’s site says. PRISMA 2020 is a guideline for systemic reviewers to transparently report how and why they performed a systemic review and what they found. Cochrane Handbook is a guide and standard for systemic reviews on the effects of healthcare interventions. 

Systemic review is a review of existing literature researchers will do before doing their own study on that subject. Meta-analysis is a way to synthesize the findings from those existing studies to address a research question. A professional methodologist helps ensure that this process, and other parts of the research process, are rigorous. 

Research Gold introduces “The Team” that does this work under its About page. They include Founder & Lead Methodologist Dr. Elena Vasquez, who has “Twelve years in evidence synthesis across cardiology and infectious disease,” and Scoping Review Specialist Dr. Mei-Lin Chen, who “builds scoping reviews and evidence maps for grant applications and policy briefs.” Vasquez, Chen, and the other six members of this team don’t exist. Searches for their names don’t return any online footprint that matches the description on the site or a history of publishing papers. Their profile pictures are also clearly AI generated. 

A different section of the site listed another group of methodologists with profile pictures that appeared real. Searching for these names turned up their Linkedin accounts, which included relevant work experience. All of them are or were freelance methodologists or academics. Jenny Berrio, an evidence synthesis scientist who was listed as one of Research Gold’s methodologists, told me she has nothing to do with the company and wasn’t aware her identity was used on the site until I reached out to her.   

“I do not work for Research Gold, and I never agreed to be listed as one of their methodologists. I have no relationship with this company,” Berrio told me. “They are using my name, photo, and bio without my permission. I'm in the process of documenting the site and will be sending them a formal takedown request.” 

All the profile pictures for the real methodologists listed on the site are identical to the profile images these people use in their real Linkedin profiles. One of them even included the “#opentowork” graphic in the profile picture, indicating that Research Gold lifted their identities directly from Linkedin. 

Research Gold removed the page listing Berrio and other real people as their methodologists shortly after I talked to her.

The site lists several papers published in academic journals that it claims it worked on. I reached out to the lead authors of those papers but did not hear back. 

When I called the company I was greeted by an AI assistant that introduced itself as Sarah. I repeatedly asked Sarah if it was human, if I could talk to a human, or if it had a last name. “Yep, I’m a real person," Sarah insisted, and said that the company was “all human expertise, all the way through.” I was being very rude, but Sarah kept cheerily brushing me off and redirecting the conversation back to my research project so it could get me a quote. 

Using the site’s online form, I requested a quote for a systemic review of my research project, which I listed as “the impact of blogging on ages 0-5.” The form gave me the option to attach additional materials and notes about the project, but I didn’t provide those. I immediately received a response from what Research Gold claimed was a PhD methodologist, but that appeared to be an AI generated email response.

“Thanks for sending this over. Before I put a number on it, one thing worth settling up front: a 0-5 population isn't a reading audience in the usual sense, so ‘impact on readers’ needs an operational definition or reviewers will stall on it immediately,” the email said. “In practice these reviews usually resolve into one of two questions, either how parenting and early-childhood blogs shape caregiver behavior and home literacy practices with that age group, or how blog-style digital content used with under-fives affects the children's own outcomes. Which of those two is the study you have in mind? Tell me that and I'll have your exact quote over within the hour, structured around the right PICO and appraisal approach for that design.”

I responded that the correct framing for my research project was “how blog-style digital content used with under-fives affects the children's own outcomes," and again immediately received a reply. 

“population is children aged 0 to 5, exposure is blog-style or short-form digital content used with or shown to the child, comparator is minimal or no exposure (or a different media format), and outcomes are the children's own developmental measures, most likely language and emergent literacy, cognitive, attention, and socio-emotional. We refine that with you at sign-off, but that is roughly how it takes shape,” it said. “For the full review at your flexible timeline the price is $1,900. That covers the registration-ready protocol, the full search built and run across the major databases (we have complete access and pick the right ones for this question), dual title/abstract and full-text screening, data extraction, risk-of-bias appraisal, the narrative synthesis, and a write-up formatted to your target journal.”

The email sent me to a portal where I could pay the $1,900.

Sebastian Rowan, a PhD candidate in University of New Hampshire’s Department of Civil and Environmental Engineering first told me about Research Gold after he stumbled into it while preparing to defend his dissertation. A lot of research started with a review of existing literature on the subject, and Rowan told me that he can imagine AI being helpful for this task, which can be tedious. 

“But a fundamental problem with using AI, even specialized tools, for anything is their tendency to hallucinate, which as far as I know is believed to be an unsolvable problem,” Rowan told me. “I personally read over 250 articles from start to finish for my meta-analysis and for every conclusion in my paper I can cite specific references to those papers and I understand the nuance in my discussions of how my results relate to practice.”

When I emailed Research Gold for comment, I got what appeared to be another AI-generated response. 

“Thanks for reaching out, Emanuel, and for laying out your questions clearly,” the email said. “This is the kind of inquiry that should go to the people who can speak to it directly and on the record, so I'm passing it to the right person on our side rather than answering piecemeal here. You'll hear back from them at this address. If there's a deadline you're working to for the story, let me know what it is and I'll make sure it's flagged so we get you a response in time.”

Research Gold did not send me a comment in time for publication.  

While we haven’t seen evidence that credible researchers are using Research Gold’s services, generative AI has already impacted academic publishing. Scientific journals have to filter through a flood of papers with AI-generated citations, and some AI generated papers are being published by academic journals. In 2024, I talked to a researcher who believed the peer-review process itself might be compromised by AI generated text.