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Monkeys, Not Humans, Likely Made Ancient Brazilian Tools

Evolution News
Photo credit: Tiago Falótico, CC BY-SA 4.0 , via Wikimedia Commons.

There’s a danger in looking too hard for evidence of our ancient ancestors. Sometimes we could be seeing things that aren’t there. One group of stone tools from 50,000 years ago could, it is now suggested, have been made by monkeys:

Excavations at Pedra Furada, a group of 800 archaeological sites in the state of Piauí, Brazil, have turned up stone shards believed to be examples of simple stone tools. Made from quartzite and quartz cobbles, the oldest ones appear to be up to 50,000 years old, which would put them among the earliest evidence of human habitation in the Western Hemisphere.

However, the tools also bear a striking resemblance to the stone tools currently made by the capuchin monkeys at Brazil’s Serra da Capivara National Park. 

SARAH CASCONE, “ANCIENT STONE TOOLS ONCE THOUGHT TO BE MADE BY HUMANS WERE ACTUALLY CRAFTED BY MONKEYS, SAY ARCHAEOLOGISTS” AT ARTNET (JANUARY 3, 2023) THE PAPER IS OPEN ACCESS.

But there’s a twist. Back in 2016, a similar point was raised at Nature:

In January, archaeologist Tomos Proffitt was examining a set of stone artefacts that his colleague Michael Haslam had brought to him. Some of the quartz pieces looked like sharpened stone tools made by human relatives in eastern Africa, some 2–3 million years ago.

But Haslam told Proffitt that the artefacts had been made the previous year by capuchin monkeys in Brazil. “I was pretty gobsmacked,” he says. “I did my PhD looking at hominin stone tools. I’ve learnt how to make these things. I was looking at this material, and it looked like it had been made by humans.” …

The capuchins make the fragments unintentionally while bashing rocks into dust, the researchers find. Some scientists say that the results call into question whether some stone tools have been incorrectly attributed to hominins — including 3.3-million-year-old artefacts from Kenya that are the oldest on record. 

EWEN CALLAWAY, “MONKEY TOOLS RAISE QUESTIONS OVER HUMAN ARCHAEOLOGICAL RECORD ” AT NATURE (OCTOBER 19, 2016) THE PAPER REQUIRES A FEE OR SUBSCRIPTION.

Not Even Tools

The twist is that those artifacts were not even tools. The monkeys were producing them accidentally…

Many life forms shape and use objects as tools: These include crows, dolphins, octopuses, alligators, and ants.

The casualty in this case is the contention — attractive to many researchers, of course — that humans were living in the Americas 50,000 years ago based on the presence of what are thought to be tools:

Coupled with the lack of other evidence of human habitation from 50,000 years ago, such as concrete traces of dietary remains or hearths — charcoal at the site could have originated from naturally occurring fires — the tools’ resemblance to rock fragments created by monkeys calls into question the likelihood that humans were responsible for their creation.

The new findings could have a major impact on our understanding of when the first humans arrived in the Americas. 

SARAH CASCONE, “ANCIENT STONE TOOLS ONCE THOUGHT TO BE MADE BY HUMANS WERE ACTUALLY CRAFTED BY MONKEYS, SAY ARCHAEOLOGISTS” AT ARTNET (JANUARY 3, 2023) THE PAPER IS OPEN ACCESS.

A Calendar in the Mix?

We need to be clear about what part of the archeological record is under question. Another current dispute, for example, turns on whether the dots that accompany many Ice Age paintings from 20,000 years ago are evidence of a lunar calendar. It’s quite likely that the series of dots and symbols represent some form of record-keeping or communication. There may or may not be a lunar calendar in the mix but there is no possibility that these artworks were created by monkeys. We know that we are in a human world here. We just aren’t sure what its inhabitants were trying to say. 

If we are going to offer theories about ancient humans, it is best to be on ground as sure as that.

Cross-posted at Mind Matters News.