Is Tool Use Monkey Business or Unique to Humans?
If you walk through a home improvement store these days, you might say to yourself, “I wish I had all of these tools.” Sophisticated tools make the job easier and they also reveal the ingenuity of the tool maker. Humans have been making tools for a long time. What do ancient stone tools tell us about human beings and other primates?
For the past quarter century, certain research groups have concluded that humans settled in South America 50,000–32,000 years ago.1 They base their conclusion on stone tools discovered at five sites in northeastern Brazil (Pedra Furada, Sitio do Meio, Vale de Pedra Furada, Toca da Tira Peia, and Santa Elina). These dates are much earlier, by at least 16,000 years, than other research studies showing that human occupation of North and South America did not begin until about 16,500 years ago.2 This discrepancy has caused some researchers to speculate that the stone tools discovered in northeastern Brazil were not manufactured by humans. Instead, they suggest that the tool makers were capuchin monkeys.
The tools found at the five Brazilian sites are simple stone tools made of locally occurring quartzite and quartz cobbles.3 They consist of hammerstones, fragmented flakes, and tabular sandstone anvil rocks. The flaking is exclusively unifacial (flaked on one face only). The stone sources were never more than 30 meters away and the anvil stones weigh about four times the weight of the hammerstones.
Who or What Made the Tools?
In 2017, archaeologist Stuart Fiedel suggested that the artifacts found at the five Brazilian sites were geofacts (rocks shaped by natural forces) rather than tools.4 He proposed that the combination of waterfalls, cascades, and gravity produced all the features in the artifacts. Archaeologist Andre Prous suggested that such natural shaping of the artifacts may have been accelerated by monkeys throwing stones from the tops of rock shelters and waterfalls.5 However, a research team led by Fabio Parenti demonstrated that it was not possible for all the artifacts to be so explained.6 At least some of the artifacts had to be manufactured.
So, who was the manufacturer? Unexpectedly, two research teams independently discovered that capuchin monkeys living in Brazil are capable of making a large number of diverse stone tools.7 Two other researchers, Tiago Falótico and Eduardo Ottoni, established that capuchin monkeys manufacture and employ both stone and plant tools with more variety and sophistication than chimpanzees.8 Primatologists now recognize that capuchin monkeys are the tool-making and tool-using champions among all nonhuman primates.
Is it possible that capuchin monkeys, not humans, manufactured the tools found at the five Brazilian sites? To settle the matter, an archaeologist and a paleontologist did a detailed comparison between the artifacts found at the Brazilian sites and tools that researchers had observed capuchin monkeys manufacturing and using.9
The two observed that at all the Brazilian Pleistocene sites the artifacts were made exclusively from immediately available raw materials. They noted that the capuchin monkeys used the tools primarily for stone-on-stone percussion for cracking open nuts and seeds and secondarily for digging. They observed the monkeys re-using broken hammerstone parts as new hammers. Some of the monkeys’ broken-off flakes appeared to be retouched but the two researchers never observed the monkeys reprocessing their stone flakes. All the flakes at the five Brazilian sites were unifacial, showing only evidence for unidirectional flaking. The sources of the stone implements were rarely more than 20 meters away and never observed to be more than 30 meters away.
In addition to the considerable positive evidence that all the artifacts were stone tools made by capuchin monkeys, the two researchers accumulated impressive negative evidence. They noted a complete lack of human manufacturing attributes among all the artifacts at the five Brazilian sites. For example, they found no evidence of hearths, blades, bifacial flakes, bifacially thinned stone tools, bones with cut marks, exotic raw materials, or any trace of symbolic behavior. At indisputable human sites the stone flakes are almost entirely bifacial or multifacial.
Researcher Luis Alberto Borrero spent more than two decades studying and dating the artifacts at the five Brazilian sites. He found no observable changes in the technological characteristics of the artifacts over a time period of a little more than 50,000 years.10 By comparison, at all human sites in South America and around the world dramatic technological advances are observed on timescales of a few centuries or less.
Foundational tenets of both nontheistic and theistic evolutionary human origins models include that (1) chimpanzees are modern humans’ closest living relative and (2) chimpanzees and humans share a relatively recent common ancestor. Hence, these models predict that chimpanzees will prove to be the most advanced tool manufacturers and users among all existent nonhuman primates. The latest field study research on wild capuchin monkeys falsifies this key prediction of evolutionary models.
Adjusting the evolutionary human origins models to make capuchin monkeys modern humans’ closest relative is not a realistic option. Adult capuchin monkeys weigh 1.4–4.0 kilograms (3–9 pounds) compared to 32–70 kilograms (70–154 pounds) for chimpanzees. Capuchin monkeys possess tails as long as their bodies while chimpanzees have no tails.
A key component of evolutionary human origins models holds that the technological capability of the bipedal primate species that preceded modern humans, especially Neanderthals and Denisovans, far surpassed that of nonhuman present-day primates. However, the latest field studies on chimpanzees and capuchin monkeys show that there are no undisputed differences between their technological capabilities and those manifested by Neanderthals and Denisovans.
Chimpanzees, capuchin monkeys, and nonhuman bipedal primates all exhibit no measurable technological advance. As noted, capuchin monkey technology has remained stagnant for the past 50,000 years. The technology exhibited by Neanderthals existing 350,000 years ago is the same as for Neanderthals existing 45,000 years ago. Likewise, anthropologists have not detected any measurable technological advance for Homo erectus during the 1.6 million years that they existed.
Human Exceptionalism and Creation Implications
Modern humans differ not just by degree, but fundamentally in kind, from Neanderthals, Denisovans, chimpanzees, and capuchin monkeys. The fossil record shows that modern humans’ technology advances explosively. Modern humans alone invent, manipulate, and use symbols. Humans alone engage in complex, extended, rapid-pace communication. We alone invent and use multiple complex languages. No other species seeks for purpose, meaning, and eternal destiny. Only humans invent and use complex trading and transportation systems. Humans alone engage in mathematics, literature, science, philosophy, and theology and we alone engage in fantasy storytelling.
These distinguishing differences summarize the tip of the iceberg of evidence for human exceptionalism. RTB scholars have written over 50 articles describing and documenting scientific evidence for human exceptionalism (see reasons.org and search for “human exceptionalism”). That evidence mounts with every passing month and year, thereby strengthening the case that humans are not evolved, but specially and uniquely created in the image of God.
- N. Guidon and G. Delibrias, “Carbon-14 Dates Point to Man in the Americas 32,000 Years Ago,” Nature 321 (June 19, 1986): 769–771, doi:10.1038/321769a0; Paul G. Bahn, “50,000-Year-Old Americans of Pedra Furada,” Nature 362 (March 11, 1993): 114–115, doi:10.1038/362114a0; Eric Boëda et al., “The Chiquihuite Cave, a Real Novelty? Observations about the Still-Ignored South American Pre-History,” PaleoAmerica 7, no. 1 (January 2021): 1–7, doi:10.1080/20555563.2020.1851500; Robin Dunnell and Linda Hurcombe, “Comment on Pedra Furada,” Antiquity 69, no. 264 (September 1995): 604–605, doi:10.1017/S0003598X0008203X; David J. Meltzer, James M. Adovasio, and Tom D. Dillehay, “On a Pleistocene Human Occupation at Pedra Furada, Brazil,” Antiquity 68, no. 261 (December 1994): 695–714, doi:10.1017/S0003598X00047414; Denis Vialou et al., “Peopling South America’s Centre: The Late-Pleistocene Site of Santa Elina,” Antiquity 91, no. 358 (August 2017): 865–884, doi:10.15184/aqy.2017.101.
- Michael R. Waters, “Late Pleistocene Exploration and Settlement of the Americas by Modern Humans,” Science 365, no. 6449 (July 12, 2019): p. eaat5447, doi:10.1126/science.aat5447; Bastien Llamas et al., “Ancient Mitochondrial DNA Provides High-Resolution Time Scale of the Peopling of the Americas,” Science Advances 2, no. 4 (April 1, 2016): id. e1501385, doi:10.1126/sciadv.1501385; Todd A. Surovell et al., “Late Date of Human Arrival to North America: Continental Scale Differences in Stratigraphic Integrity of Pre-13,000 BP Archaeological Sites,” PLoS One 17, no. 4 (April 2022): id. e0264092, doi:10.1371/journal.pone.0264092; Ted Goebel, Michael R. Waters, and Dennis H. O’Rourke, “The Late Pleistocene Dispersal of Modern Humans in the Americas,” Science 319, no. 5869 (March 14, 2008): 1497–1502, doi:10.1126/science.1153569.
- Guidon and Delibrias, “Carbon-14 Dates Point to Man,” doi:10.1038/321769a0.
- Stuart J. Fiedel, “Did Monkeys Make the Pre-Clovis Pebble Tools of Northeastern Brazil?,” PaleoAmerica 3, no. 1 (March 2017): 6–12, doi:10.1080/20555563.2016.1273000.
- André Prous, “O Povoamento da América Visto do Brasil: Uma Perspectiva Crítica,” Revista da USP: Dossiê Surgi-Mento do Homem na América 0, no. 34 (August 1997): 8–21, doi:10.11606/issn.2316-9036.v0i34p8-21.
- Fabio Parenti et al., “Genesis and Taphonomy of the Archaeological Layers of Pedra Furada Rock-Shelter, Brazil,” Quaternaire 29, no. 3 (September 2018): 255–269, doi:10.4000/quaternaire.10313.
- Michael Haslam et al., “Pre-Columbian Monkey Tools,” Current Biology 26, no. 13 (July 11, 2016): PR521–R522, doi:10.1016/j.cub.2016.05.046; Tomos Profitt et al., “Wild Monkeys Flake Stone Tools,” Nature 539 (November 3, 2016): 85–88, doi:10.1038/nature20112.
- Tiago Falótico and Eduardo B. Ottoni, “Sexual Bias in Probe Tool Manufacture and Use by Wild Bearded Capuchin Monkeys,” Behavioural Processes 108 (October 2014): 117–122, doi:10.1016/j.beproc.2014.09.036; Tiago Falótico and Eduardo B. Ottoni, “The Manifold Use of Pounding Stone Tools by Wild Capuchin Monkeys of Serra da Capivara National Park, Brazil,” Behaviour 153, no. 4 (April 21, 2016): 421–442, doi:10.1163/1568539X-00003357.
- Agustin M. Agnolin and Federico I. Agnolin, “Holocene Capuchin-Monkey Stone Tool Deposits Shed Doubts on the Human Origin of Archeological Sites from the Pleistocene in Brazil,” The Holocene (online, ahead of print, November 15, 2022), doi:10.1177/09596836221131707.
- Luis Alberto Borrero, “Human and Natural Agency: Some Comments on Pedra Furada,” Antiquity 69, no. 264 (September 1995): 602–603, doi:10.1017/S0003598X00082028; Luis Alberto Borrero, “Ambiguity and Debates on the Early Peopling of South America,” PaleoAmerica 2, no. 1 (March 2016): 11–21, doi:10.1080/20555563.2015.1136498.