FIRE, COOKING AND HOMO ERECTUS

HOMO ERECTUS FOOD

Homo erectus was considerably larger than its forebears. Scientists speculate that the reason for this is that they ate more meat. There is evidence that they ate meat 2.5 million years ago, based on bones found at sites, where “Homo erectus” fossils and tools were food, but their bodies did not begin to get bigger until around 1.9 million years ago, which is when homonids are believed to invented fire.

Homo erectus had smaller teeth and less powerful jaws than the australopithecines. Richard Wrangham of Harvard wrote the journal Current Anthropology that this may have meant that “Homo erectus” cooked the vegetables that they ate and thus were able to eat a wider variety of roots and vegetables with more nutrients.

Extensive analysis of chemicals found on the teeth of a 1.8-million-year-old”Paranthropus” skull found at Swartkrans in South Africa revealed the hominin ate fruits, nuts, sedges, grasses, herbs, seeds, tree leaves and potato-like tubers and roots. Meat may have been eaten but it is difficult to tell whether it was scavenged or hunted. The research, published in Science in November 2006, was carried out by team led by Matt Sponheimer of the University of Colorado. The data also seems to suggest these early hominins traveled to different places depending on the rainfall amounts and seasons and found food in grasslands, forests and scattered woods. Because teeth build over time the scientists were able to establish what was eaten over a period of months and years by examining different layers of enamel.

Chemical traces found on different layers of tooth enamel revealed that these early hominins changed their feeding month to month, which raises questions about theories that suggest these species became extinct because they were unable to adapt to environmental changes and suggests that perhaps they became extinct because they were outcompeted by more advanced homo species. Professor Thure Cerling of the University of Utah told the Times of London, “This shows the variability in human diet has been “in the family” for a very long time. Hominins were taking advantage of seasonal differences in food items in a savanna environment. We cannot tell if they were carnivores but it is possible their diet included animals . We are picking up that signal.”

Excavations all over the world shown a large variety of plants and animals were exploited for food at the time “Homo erectus” lived.Scholars believe that men may have learned what foods to eat by watching other animals, and through trial and error experimentation. Early man may have discovered early intoxicants and medicines this same way.

Alok Jha wrote in The Guardian: “The earliest evidence of controlled fire for cooking, was found last year in South Africa by scientists at the University of Boston and dated to a million years ago. It is thought that the development of cooking not only made food tastier and easier to digest, it made the extraction of energy from raw ingredients quicker and more efficient. All useful things if you want to power an over-sized, energy-hungry brain without having to spend all your time foraging and chewing food. [Source: Alok Jha, The Guardian, November 15, 2012 |=|]

Protein and fat in the bones and skulls of prey are excellent food sources for growing stronger bodies and larger brains. Some scientists argue that running helped our ancestors reach food sources to scavenge and this helped them acquire the protein and fat needed to grow the kind of brain that makes us human. Daniel Lieberman of Harvard University told the Harvard Gazette: “Imagine what life was like for our ancestors on the plains of Africa some 2-3 million years ago“How would you obtain a high protein meal without any weapons?” William J. Cromie wrote in the Harvard News: “He describes a scenario of H. erectus “shopping.” Seeing vultures in the sky tips him off that there’s meat and marrow nearby. If he walks to the kill, hyenas and other scavengers will get what meat, marrow, and brains the big hunters like lions have left. You’ve got to run, and the faster, the better. [Source: William J. Cromie, Harvard News, November 18, 2004 ^=^]

Websites and Resources on Hominins and Human Origins: Smithsonian Human Origins Program humanorigins.si.edu ; Institute of Human Origins iho.asu.edu ; Becoming Human University of Arizona site becominghuman.org ; Talk Origins Index talkorigins.org/origins ; Last updated 2006. Hall of Human Origins American Museum of Natural History amnh.org/exhibitions ; Wikipedia article on Human Evolution Wikipedia ; Human Evolution Images evolution-textbook.org; Hominin Species talkorigins.org ; Paleoanthropology Links talkorigins.org ; Britannica Human Evolution britannica.com ; Human Evolution handprint.com ; National Geographic Map of Human Migrations genographic.nationalgeographic.com ; Humin Origins Washington State University wsu.edu/gened/learn-modules ; University of California Museum of Anthropology ucmp.berkeley.edu; BBC The evolution of man" bbc.co.uk/sn/prehistoric_life; "Bones, Stones and Genes: The Origin of Modern Humans" (Video lecture series). Howard Hughes Medical Institute.; Human Evolution Timeline ArchaeologyInfo.com ; Walking with Cavemen (BBC) bbc.co.uk/sn/prehistoric_life ; PBS Evolution: Humans pbs.org/wgbh/evolution/humans; PBS: Human Evolution Library www.pbs.org/wgbh/evolution/library; Human Evolution: you try it, from PBS pbs.org/wgbh/aso/tryit/evolution; John Hawks' Anthropology Weblog johnhawks.net/ ; New Scientist: Human Evolution newscientist.com/article-topic/human-evolution; Fossil Sites and Organizations: The Paleoanthropology Society paleoanthro.org; Institute of Human Origins (Don Johanson's organization) iho.asu.edu/; The Leakey Foundation leakeyfoundation.org; The Stone Age Institute stoneageinstitute.org; The Bradshaw Foundation bradshawfoundation.com ; Turkana Basin Institute turkanabasin.org; Koobi Fora Research Project kfrp.com; Maropeng Cradle of Humankind, South Africa maropeng.co.za ; Blombus Cave Project web.archive.org/web; Journals: Journal of Human Evolution journals.elsevier.com/; American Journal of Physical Anthropology onlinelibrary.wiley.com; Evolutionary Anthropology onlinelibrary.wiley.com; Comptes Rendus Palevol journals.elsevier.com/ ; PaleoAnthropology paleoanthro.org.

Earliest Evidence of Hominin Hunting and Scavenging

1 million-year-old Oldowon ax

Beginning around two million years ago, early stone tool-making humans, known scientifically as Oldowan hominin, started to exhibit a number of physiological and ecological adaptations that required greater daily energy expenditures, including an increase in brain and body size, heavier investment in their offspring and significant home-range expansion. Demonstrating how these early humans acquired the extra energy they needed to sustain these shifts has been the subject of much debate among researchers. A recent study led by Joseph Ferraro, Ph.D., assistant professor of anthropology at Baylor, offers new insight in this debate with a wealth of archaeological evidence from the two million-year-old site of Kanjera South (KJS), Kenya. The study’s findings were recently published in PLOS One.

According to Past Horizons: “Considered in total, this study provides important early archaeological evidence for meat eating, hunting and scavenging behaviour -cornerstone adaptations that likely facilitated brain expansion in human evolution, movement of hominins out of Africa and into Eurasia, as well as important shifts in our social behaviour, anatomy and physiology,” Ferraro said. Located on the shores of Lake Victoria, KJS contains “three large, well-preserved, stratified” layers of animal remains. The research team worked at the site for more than a decade, recovering thousands of animal bones and rudimentary stone tools. [Source:Past Horizons, May 10, 2013 ^^]

“According to researchers, hominins at KJS met their new energy requirements through an increased reliance on meat eating. Specifically, the archaeological record at KJS shows that hominins acquired an abundance of nutritious animal remains through a combination of both hunting and scavenging behaviours. The KJS site is the earliest known archaeological evidence of these behaviours. Our study helps inform the ‘hunting vs. scavenging’ debate in Palaeolithic archaeology. The record at KJS shows that it isn’t a case of either/or for Oldowan hominins two million years ago. Rather hominins at KJS were clearly doing both,” Ferraro said. ^^

“The fossil evidence for hominin hunting is particularly compelling. The record shows that Oldowan hominins acquired and butchered numerous small antelope carcasses. These animals are well represented at the site by most or all of their bones from the tops of their head to the tips of their hooves, indicating to researchers that they were transported to the site as whole carcasses. Many of the bones also show evidence of cut marks made when hominins used simple stone tools to remove animal flesh. Some bones also bear evidence that hominins used fist-sized stones to break them open to acquire bone marrow. In addition, modern studies in the Serengeti–an environment similar to KJS two million years ago–have also shown that predators completely devour antelopes of this size within minutes of their deaths. As a result, hominins could only have acquired these valuable remains on the savanna through active hunting. ^^ “The site also contains a large number of isolated heads of wildebeest-sized antelopes. In contrast to small antelope carcasses, the heads of these somewhat larger individuals are able to be consumed several days after death and could be scavenged, as even the largest African predators like lions and hyenas were unable to break them open to access their nutrient-rich brains. “Tool-wielding hominins at KJS, on the other hand, could access this tissue and likely did so by scavenging these heads after the initial non-human hunters had consumed the rest of the carcass,” Ferraro said. “KJS hominins not only scavenged these head remains, they also transported them some distance to the archaeological site before breaking them open and consuming the brains. This is important because it provides the earliest archaeological evidence of this type of resource transport behaviour in the human lineage.”“ ^^

Evidence of Hominin Hunting from 2 Million Years Ago

Evidence from an ancient butchery site in Tanzania shows that hominins was capable of ambushing herds of large animals about 2 million years ago, 1.6 million years earlier than previously thought. Robin McKie wrote in The Guardian: “Ancient humans used complex hunting techniques to ambush and kill antelopes, gazelles, wildebeest and other large animals at least two million years ago. The discovery – made by anthropologist Professor Henry Bunn of Wisconsin University – pushes back the definitive date for the beginning of systematic human hunting by hundreds of thousands of years.[Source: Robin McKie, The Guardian, September 23, 2012 |=|]

“Two million years ago, our human ancestors were small-brained apemen and in the past many scientists have assumed the meat they ate had been gathered from animals that had died from natural causes or had been left behind by lions, leopards and other carnivores. But Bunn argues that our apemen ancestors, although primitive and fairly puny, were capable of ambushing herds of large animals after carefully selecting individuals for slaughter. The appearance of this skill so early in our evolutionary past has key implications for the development of human intellect. “We know that humans ate meat two million years ago,” said Bunn, who was speaking in Bordeaux at the annual meeting of the European Society for the study of Human Evolution (ESHE). “What was not clear was the source of that meat. However, we have compared the type of prey killed by lions and leopards today with the type of prey selected by humans in those days. This has shown that men and women could not have been taking kill from other animals or eating those that had died of natural causes. They were selecting and killing what they wanted.” |=|

“Bunn believes these early humans probably sat in trees and waited until herds of antelopes or gazelles passed below, then speared them at point-blank range. This skill, developed far earlier than suspected, was to have profound implications. Once our species got a taste for meat, it was provided with a dense, protein-rich source of energy. We no longer needed to invest internal resources on huge digestive tracts that were previously required to process vegetation and fruit, which are more difficult to digest. Freed from that task by meat, the new, energy-rich resources were then diverted inside our bodies and used to fuel our growing brains.” |As a result, over the next two million years our crania grew, producing species of humans with increasingly large brains – until this carnivorous predilection produced Homo sapiens.” |=|

2-Million-Year-Old Hominin Hunters: Picked Strong Animals Not the Weak and Old

Robin McKie wrote in The Guardian: “ In his study, Bunn and his colleagues looked at a huge butchery site in the Olduvai Gorge in Tanzania. The carcasses of wildebeest, antelopes and gazelles were brought there by ancient humans, most probably members of the species Homo habilis, more than 1.8 million years ago. The meat was then stripped from the animals’ bones and eaten. [Source: Robin McKie, The Guardian, September 23, 2012 |=|]

“We decided to look at the ages of the animals that had been dragged there,” said Benn. “By studying the teeth in the skulls that were left, we could get a very precise indication of what type of meat these early humans were consuming. Were they bringing back creatures that were in their prime or were old or young? Then we compared our results with the kinds of animals killed by lions and leopards.”

The results for several species of large antelope Bunn analysed showed that humans preferred only adult animals in their prime, for example. Lions and leopards killed old, young and adults indiscriminately. For small antelope species, the picture was slightly different. Humans preferred only older animals, while lions and leopards had a fancy only for adults in their prime.

“For all the animals we looked at, we found a completely different pattern of meat preference between ancient humans and other carnivores, indicating that we were not just scavenging from lions and leopards and taking their leftovers. We were picking what we wanted and were killing it ourselves.”

2-Million-Year-Old Hunting: Does That Mean We Are Prone to Violence?

That finding that hominin hunting dates back to 2 million years ago rather than a few hundred thousand years ago has major implications. Bunn said: “Until now the oldest, unambiguous evidence of human hunting has come from a 400,000-year-old site in Germany where horses were clearly being speared and their flesh eaten. We have now pushed that date back to around two million years ago.” [Source: Robin McKie, The Guardian, September 23, 2012 |=|]

Robin McKie wrote in The Guardian: “The hunting instinct of early humans is a controversial subject. In the first half of the 20th century, many scientists argued that our ancestors’ urge to hunt and kill drove us to develop spears and axes and to evolve bigger and bigger brains in order to handle these increasingly complex weapons. Extreme violence is in our nature, it was argued by fossil experts such as Raymond Dart and writers like Robert Ardrey, whose book African Genesis on the subject was particularly influential.

“By the 80s, the idea had run out of favour, and scientists argued that our larger brains evolved mainly to help us co-operate with each other. We developed language and other skills that helped us maintain complex societies. “I don’t disagree with this scenario,” said Bunn. “But it has led us to downplay the hunting abilities of our early ancestors. People have dismissed them as mere scavengers and I don’t think that looks right any more.”

Cooking Helped Homo Erectus Develop 2 Million Years Ago?

Chimpanzees, gorillas and other non-human primates spend nearly half their time eating. Research announced in 2011 suggested that Homo erectus learned how to cook 2 million years ago, allowing it to save time and extract more nutrients and this paved for the way for bigger brains. “In the big picture, eating cooked food has huge ramifications,” says Harvard’s Chris Organ, a coauthor of the study that presented this theory. [Source:Rachel Ehrenberg, sciencenews.org, August 22, 2011 /^]

Rachel Ehrenberg wrote in sciencenews.org: “Cooking and other food-processing techniques aren’t just time-savers; they provide a bigger nutritional punch than a raw diet. The new work is further evidence that cooking literally provided food for thought, making it easier for the body to extract calories from the diet that could then be used to grow a nice, big brain. Humans are the only animals who cook, and compared to our living primate relatives we spend very little time gathering and eating food. We also have smaller jaws and teeth. /^\

“Homo erectus also had small teeth relative to others in the human lineage, and the going idea was that hominins must have figured out how to soften up their food by the time that H. erectus evolved. But behavioral traits such as the ability to whip up a puree or barbecue ribs don’t fossilize, so a real rigorous test of the H. erectus-as-chef hypothesis was lacking. /^\

“Organ and his colleagues, including Harvard’s Richard Wrangham, an early champion of the cooking hypothesis, decided to quantify the time one would expect humans to spend eating by looking at body size and feeding time in our living primate relatives. After building a family tree of primates, the researchers found that people spend a tenth as much time eating relative to their body size compared with their evolutionary cousins — a mere 4.7 percent of daily activity rather than the expected 48 percent if humans fed like other primates. /^\

“Then the team looked at tooth size within the genus Homo. From H. erectus on down to H. sapiens, teeth are much smaller than would be predicted based on what is seen in other primates, the team reports online the week of August 22 in the Proceedings of the National Academy of Sciences. “Tooth size becomes dramatically smaller than what we would expect,” says paleoanthropologist David Strait of the University at Albany in New York, who was not involved with the work. “This is really compelling indirect evidence the human lineage became adapted to and dependent on cooking their food by the time Homo erectus evolved.” /^\

Fire and Homo Erectus

Sangiran Homo erectus Diorama Homo erectus learned to control fire about one million years ago. Some scientists speculate that early hominins gathered smoldering wood from lighting-ignited fires and used it to cook meat, and perhaps kept the coals burning so they could use the fire repeatedly over a relatively long period of time.

Some scientists suggest that fire may have been tamed as early as 1.8 million years ago based on the theory that Homo erectus needed to cook food such as tough meat, tubers and roots to make them edible. Some even speculate that australopthecines were the first to tame fire. The theory suggests that climate changes around 1.9 million years forced hominins to begin eating food like tubers, which they had hadn't eaten before but started eating then because no other food was available.

Archaeologists consider the emergence of stone tool manufacturing and the control of fire as the two hallmark events in the technological evolution of early humans. While experts agree the origins of stone tools date back at least 2.5 million years in Africa, the origin of fire control has been a prolonged and heated debate.

Although scientists estimate that hominin have been using fire for over a million, it is unclear they started using it on a regular basis, such as for cooking daily meals. According to to Associated Press: “Over the years, some experts have cited evidence of fire from as long as 1.5 million years ago, and some have argued it was used even earlier, a key step toward evolution of a larger brain. It's a tricky issue. Even if you find evidence of an ancient blaze, how do you know it wasn't just a wildfire?”

Zach Zorich wrote in Archaeology: “Some paleoanthropologists believe that people have been eating cooked food, and therefore making fires, for millions of years. The evidence for this, so far, has been evolutionary changes in hominin skeletons, such as decreasing tooth and jaw sizes. But there has been very little direct archaeological evidence of fire use prior to 700,000 years ago.” [Source:Zach Zorich, Archaeology, Volume 65 Number 4, July/August 2012]

Homo erectus is believed to have learned to control fire about one million years ago. Some scientist speculate that early hominids gathered smoldering wood from lighting-ignited fires and used it to cook meat. University of Toronto anthropologist Michael Chazan said: "The control of fire would have been a major turning point in human evolution. The impact of cooking food is well documented, but the impact of control over fire would have touched all elements of human society. Socializing around a camp fire might actually be an essential aspect of what makes us human."

Evidence of Fire and Homo Erectus

20120202-Caune de Arago.jpg
Caune de Arago Evidence of very old fires backing up the theory mentioned above include thermally altered stone artifacts and circles of burned clay that have been dated to between 1.5 million and 1.7 million years ago. Charred animal bones found in Swartkrans cave near Pretoria have been dated to 1.5 million years. Anthropologists who study hunters and gatherers say that fires made by these people are small and leave little evidence.

The oldest largely accepted evidence of fire used by “Homo erectus” are burned animals bones found among remains of “ Homo erectus” in the same caves in Zhoukoudian, China where Peking man was found. The burned bones have been dated to about 500,000 years old. In Europe, there is evidence of 400,000-year-old, hominin-made fires.

Critics argue that the charred animal bones could simply be the remains of bones in naturally occurring fires. Studies of the ashes in Zhoukoudian indicate they may have been produced by natural causes and washed into the cave.

The earliest really hard evidence of fire comes in the form of stone hearths and clay ovens made in the last 250,000 years by archaic humans. Human control of fire is well documented at sites dating from 150,000 to 200,000 years ago, and remains of hearths between 300,000 and 400,000 years old have been found at a handful of sites in France, Hungary, and China.

In 1997, archaeologists from Liverpool University announced they found what may be one of Europe's oldest hearths at a 400,000-year-old Stone Age site in southeastern England. The find consisted of an area of red, baked sediments, whose limited expanse suggests a controlled fire rather than a natural one. The burnt sediments have been removed intact as part of a one-cubic-meter block so laboratory tests can be undertaken to help identify the nature of the burning. [Source: Archaeology magazine, Theresa A. McGill, November/December 1997]

The site, near Bury St. Edmunds in Suffolk, was in a favorable spot near a source of water. According to John Gowlett, who is directing the excavation, it seems to have been used over centuries during a lull between the Ice Ages, when numerous large mammals, including bear and deer, undoubtedly hunted by early humans, were found in the area. Thousands of flint flakes have been discovered at the camp, the by-products of stone tool manufacturing, and many have been matched to the cores from which they were struck. [Ibid]

Hominin Appear to Have Used Fire 1 Million Years Ago in South Africa

Wonderwerk Cave

Swartkrans—a cave that is home to an abundance of stone and bone tools dating back almost two million years — is also the source of 270 burned bones estimated to be more than one million years old. These bones may be evidence of the earliest known controlled fires. [Source: Erin Wayman, Smithsonian Magazine, January 2012]

Ash and burnt bone samples found at South Africa's Wonderwerk Cave — a massive cave located near the edge of the Kalahar i— suggest fires were frequently burned there. Research associated with that site makes "a pretty strong case" for the site in South Africa's Wonderwerk Cave, said Francesco Berna of Boston University, who presented the work with colleagues in the Proceedings of the National Academy of Sciences. Using a technique that allows researchers to conduct microscopic analysis of the chemical composition of a sample, scientists were able to identify burned pieces of bone and plant material in the cave's sediments. [Source: Malcolm Ritter, Associated Press, April 4, 2012 ~]

Malcolm Ritter of Associated Press wrote: One expert said the new finding should be considered together with a previous discovery nearby, of about the same age. Burnt bones also have been found in the Swartkrans cave, not far from the new site, and the combination makes a stronger case than either one alone, said Anne Skinner of Williams College in Williamstown, Mass., who was not involved in the new study. Another expert unconnected with the work, Wil Roebroeks of Leiden University in The Netherlands, said that while the new research does not provide "rock solid" evidence, it suggests our ancestors probably did use fire there at that time. ~

“The ancestors probably brought burning material from natural blazes into the cave to establish the fires, said Michael Chazan of the University of Toronto, a study author. Stone tools at the site suggest the ancestors were Homo erectus, a species known from as early as about 2 million years ago. The scientists didn't find signs of fire preparation, like a hearth or a deep pit. But Berna said it's unlikely the fires were simply natural blazes, such as from lightning strikes. That's because the evidence shows repeated fires burned deep inside the cave, he said. The cave entrance is almost 100 feet away, and because of changes in the cave over the past 1 million years, the entrance was apparently even farther away when the fires burned, he said. In contrast, he said, the bones at Swartkrans could have been burned by a natural fire in the open before winding up in that cave. ~

“The scientists also found no sign that the Wonderwerk cave fires were ignited by spontaneous combustion of bat guano, which they called a rare but documented event. Berna and colleagues describe animal bones that show discoloring and a chemical signature of being heated. They also report microscopic bits of ash in excavated dirt from the cave, indicating burning of light material like leaves, grasses and twigs. And they found evidence of heating in samples of fractured stone. Several lines of evidence suggest the material was heated within the cave rather than blown or washed in from outside. It's not clear what the fires were used for. While the burnt bones suggest cooking, the ancestors might have eaten the meat raw and tossed the bones into the fire, Berna noted. Other possible uses might be warmth, light and protection from wild animals, he said. ~

“In a statement to The Associated Press, Roebroeks and Paola Villa of the University of the Witwatersrand in Johannesburg, South Africa, and the University of Colorado Museum in Boulder, said that while the new study probably demonstrates use of fire, they'd like to see signs of preparations like a hearth to be sure. In any case, they said, the work does not show that human ancestors were using fire regularly throughout their range that long ago. In a paper published in 2011, they traced such habitual use of fire to about 400,000 years ago.” ~

Research at Wonderwerk Cave

Wonderwerk Cave

On how the discovery of fire use at Wonderwerk Cave took place, Kenneth Miller wrote in Discover: “Like many archaeological discoveries, this one was accidental. Researchers weren’t looking for signs of prehistoric fire; they were trying to determine the age of sediments in a section of the cave where other researchers had found primitive stone tools. In the process, the team unearthed what appeared to be the remains of campfires from a million years ago — 200,000 years older than any other firm evidence of human-controlled fire. Their findings also fanned the flames of a decade-old debate over the influence of fire, particularly cooking, on the evolution of our species’s relatively capacious brains. [Source: Kenneth Miller, Discover, December 17, 2013 /+]

“At Wonderwerk, Boston University archaeologist Paul Goldberg — a specialist in soil micromorphology, or the small-scale study of sediments — dug chunks of compacted dirt from the old excavation area. He then dried them out and soaked them in a polyester resin so they would harden to a rocklike consistency. Once the blocks solidified, researchers sawed them into wafer-thin slices. The “eureka” moment came later, as the slices were examined under a microscope at Israel’s Weizmann Institute. “Holy cow!” Goldberg exclaimed. “There’s ashes in there!”/+\

“He and his colleagues saw carbonized leaf and twig fragments. Looking more closely, they identified burned bits of animal bones as well. The bones’ sharp edges, and the excellent preservation of the plant ash, indicated that neither wind nor rain had ushered in the burnt material. The burning clearly had occurred inside the cave./+\

“Then team member Francesco Berna subjected the sample to a test called Fourier transform infrared microspectroscopy (FTIR), which analyzes a material’s composition by measuring the way it absorbs infrared waves. Often used in crime labs to identify traces of drugs and fibers, FTIR can also determine the temperature to which organic matter has been heated — and Berna is among the first to adapt it for archaeology. When he ran an FTIR analysis on one of the sediment slices, the sample’s infrared signature showed that the cave material had been heated to between 750 and 1,300 degrees Fahrenheit. That was just right for a small fire made of twigs and grasses.” /+\

Quest for Evidence of the Earliest Fire

Kenneth Miller wrote in Discover: “The clues indicating early use of fire tend to be subtle; it’s easy to miss them, but it’s also easy to see them when they’re not really there. What looks like charring on a rock or bone, for example, often turns out to be staining from minerals or fungus. And high-tech analytic techniques don’t always banish the ambiguity. [Source: Kenneth Miller, Discover, December 17, 2013 /+]

“In recent decades, a number of sites have vied for the title of earliest human-controlled fire. At Koobi Fora and Chesowanja, both in Kenya, small patches of reddened soil were found in areas containing stone tools up to 1.5 million years old. To try to prove that Early Stone Age campfires caused the discoloration, researchers in the 1980s and ’90s used techniques such as magnetic susceptibility analysis and thermoluminescence dating. The first tool detects burned earth by gauging fluctuations in its magnetic field; the second determines how long ago an object was heated by measuring the photons it emits when baked in a lab. Although these methods showed that burning had occurred, the evidence is simply too sparse to convince most archaeologists that humans — not wildfires or lightning — were responsible./+\

“Another promising site is a South African cave called Swartkrans, where archaeologists in the ’80s found burned bones in a section dating between 1 million and 1.5 million years ago. In 2004, Williams College chemist Anne Skinner analyzed the bones using electron spin resonance, which estimates the temperature to which an artifact has been heated by measuring molecular fragments called free radicals. She determined that the bones had reached at least 900 degrees — too hot for most wildfires, but consistent with a campfire. But since the cave has a gaping mouth and a downward-sloping floor, naysayers argue that the objects might have washed in later after being burned outside./+\

“Until the Wonderwerk Cave find, Gesher Benot Ya’aqov, a lakeside site in Israel, was considered to have the oldest generally accepted evidence of human-controlled fire. There, a team of scientists found traces of numerous hearths dating to between 690,000 and 790,000 years ago. A wide range of clues made this site convincing, including isolated clusters of burned flint, as if toolmakers had been knapping hand axes by several firesides. The team also found fragments of burned fruit, grain and wood scattered about./+\

“Then came Wonderwerk. The ash-filled sediment that Goldberg and Berna found came from a spot approximately 100 feet from the entrance to the tunnel-like cave, too far to have been swept in by the elements. The team also found circular chips of fractured stone known as pot-lid flakes — telltale signs of fire — in the same area. These clues turned up throughout the million-year-old layer of sediment, indicating that fires had burned repeatedly at the site.”/+\

“Does that mean fire drove the evolution of H. erectus? Is the cooking hypothesis correct? The occupants who left these ashes at Wonderwerk lived nearly a million years after the emergence of H. erectus. Goldberg and Berna point out that it’s unclear whether the cave’s inhabitants knew how to start a fire from scratch or depended on flames harvested from grass fires outside the cave. If they were eating barbecue, it may have been only an occasional luxury. Whether that could have had an impact on human development remains an open question.” /+\

Humans Started Fires in Israel 790,000 Years Ago?

A study by Israel scientists suggests that hominins learned to start fires about 790,000 years ago and this may have played a role in the migration of ancient humans from Africa to Europe. Although no ancient matches or other kind of fire starter were found at the site, experts believe that burned flint patterns found in the same place proves a fire-making ability, Reuters reported. [Source: Ancient Foods, PressTV, October 27, 2008]

According to PressTV: “Studying the flints found at an archaeological site on the bank of the river Jordan, Hebrew University scientists in Jerusalem (al-Quds) found that ancient humans could start fire, rather than relying on natural phenomena such as lightning. “The new data shows there was a continued, controlled use of fire through many civilizations and that they were not dependent on natural fires,” archaeologist Nira Alperson-Afil said.

“Since the site is located in the Jordan valley, between Africa and Europe, experts believe the invention of fire has had a great role in the migration of humans northward. “Once they mastered fire to protect themselves from predators and provide warmth and light, they were secure enough to move into and populate unfamiliar territory,” said Alperson-Afil.

In June 2015, scientists announced that they had firm evidence that fire was being used on a regular basis at Quesem Cave in Israel more than 300,000 years ago as evidenced by large quantities of burnt bone, heated soil lumps, ash deposits, and most significantly, a 300,000-year-old hearth in the center of the cave. An analysis of the hearth revealed that it has been used repeatedly over time. [Source :Mark Miller, Ancient Origins, July 22, 2015]

Peking Man and Fire

Peking Man

For a long time, one of the oldest largely-accepted examples of fire used by an ancestor of modern humans is a group of burned animals bones found among remains of Homo erectus in the same caves in Zhoukoudian, China where Peking man was found. The burned bones have been dated to be about 500,000 years old. In Europe, there is evidence of fire that is 400,000 years old.

In 2015, Chinese scientists asserted that Peking Man set up fireplaces and cooked food about 600,000 years ago—the earliest evidence for fire use by a human species. They found fireplaces enclosed by a circle of rocks and burned rocks, soil and bones at the Zhoukoudian site. Gao Xing, with the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences, said archaeologists spent three years excavating the site and found lime that he says resulted from limestone being burned."Source: Mark Miller, Ancient Origins, July 22, 2015 /*/]

The China Daily reported: “A fire site, sintering soil, and burned rocks and bones were uncovered at the site, said Gao Xing."Some of the animal bones were entirely carbonized, turned black both outside and inside," Gao said. "It is safe for us to conclude that this is the result of burning." Fire sites encircled by rocks and lime resulting from the burning of limestone were also found, Gao said. [Source: China Daily, July 19, 2015 |+|]

Ashes, burned bones and rocks, as well as charred seeds were also found at Zhoukoudian fame in 1929, Gao said, leading many archaeologists to agree that Peking Man knew how to use fire. But there has always been skepticism that they resulted from natural fire. "The evidence this time is more convincing," Gao said. "It has been found under the earth untouched, without weather damage. "This shows us that Peking Man could not only keep kindling, but knew how to control fire." |+|

Mark Miller wrote in Ancient Origins: “Although scientists estimate that ancient humans began using fire over a million years ago, it had been unclear when people starting using it on a regular basis, for example, for cooking daily meals. Discoveries earlier this year in Quesem Cave in Israel confirmed people were using fire 300,000 years ago, but the Zhoukoudian find provides even earlier evidence. /*/

Fire an Inspiration for Hominins

Some scientists say there is evidence suggesting that fire may have influenced the evolution of the human mind. Thomas Wynn wrote in Smithsonian Magazine: “It’s well-known that fire enabled the survival of early humans by providing warmth as well as a means to cook food and forge better weapons. Yet research into cognitive evolution—a field of study that brings together psychology, anthropology, neuroscience and genetics—suggests that fire’s most lasting impact was how our responses to it altered our brains, helping endow us with capabilities such as long-term memory and problem-solving. [Source: Thomas Wynn, Smithsonian Magazine, December 2012 /^]

“Archaeological evidence suggests that the controlled use of fire began with Homo erectus, who emerged nearly two million years ago. For those early hominins, a fire at night served as a light source and a way to deter predators. John Gowlett, a University of Liverpool archaeologist, argues that this innovation led to a profound change in how our brains regulate time. After the sun goes down, our ape cousins spend the entire evening asleep or inactive in nests. But the creation of artificial daylight enabled the hominin brain to adapt and evolve to the point where humans now remain alert and active for over 16 hours a day./^\

“Psychologist Frederick L. Coolidge of the University of Colorado further argues that fire altered the quality of sleep. During rapid eye movement (REM) sleep, the most vivid dreaming occurs and the brain consolidates long-term “procedural memories,” which allow us to retain skills and repeat previously learned tasks. The downside is that REM sleep is accompanied by a form of near paralysis known as muscle atonia—not the state you want to be in if you’re surrounded by animals that want to eat you. Using fire to keep predators away would have made it safe for early hominins to indulge in more REM (modern humans spend 25 percent of sleep in REM, compared with up to 15 percent for apes and monkeys), improving their ability to learn multistep tasks such as tool manufacturing. /^\

“Fire might also have improved our ability to think about many things at once and relate them to one another. This “working memory”?is an essential trait for imagining and executing complicated plans. Psychologist Matt Rossano of Southeastern Louisiana University speculates that small social groups first achieved this altered mental state some 100,000 years ago around the campfire. Focusing on a specific object—in this case, fire—is a way to achieve a meditative state. The brain regions that activate to trigger meditation overlap extensively with the regions governing working memory. And, since meditation also has benefits for health, Rossano proposes that evolution would have favored those who were good meditators, allowing them to pass their ability along to their progeny. /^\

“By regulating attention, our ancestors were able to make contingency plans—in which alternative responses to problems were planned in advance. These attributes gave us a marked advantage in the face of competition from archaic humans such as Neanderthals; they also underpin our ability to cope with the huge variety of tasks required by modern life. The most enduring tool that fire ever made might just be the human mind. The next time you find yourself lost in thought while gazing at a fireplace ablaze or even a solitary candle flame, consider this: Being mesmerized by fire might have sparked the evolution of the human mind.” /^\

Cooking and Hominins

Some scientists suggest that fire may have been tamed as early as 1.8 million years ago based on the theory that Homo erectus needed to cook food such as tough meat, tubers and roots to make them edible. Cooked food is more edible and easy to digest. It takes a chimpanzee about an hour to absorb 400 calories from eating raw meat. By contrast it takes a modern human only a couple minutes to wolf down the same amount of calories in a sandwich.

Cooked food is more edible and easy to digest. It takes a chimpanzee about an hour to absorb 400 calories from eating raw meat. By contrast it takes a modern human only a couple minutes to wolf down the same amount of calories in a sandwich.

Some scholars have speculated that the invention of fire turned men from solitary eaters into communal ones. Cooking was a great advancement. With softer, meat, hominins could dispense with their heavy, grinding teeth and extensive guts (modern human intestines occupy a fifth of their gut compared to 50 percent in chimpanzee’s). In 1773, James Boswell wrote: “My definition of Man is a ‘Cooking Animal.’”

Ian Sample wrote in The Guardian:“The advent of cooking was one of the most crucial episodes in the human story, allowing our ancestors to broaden their diet and extract more calories from their food. Because it softened food, it also spelled an end to the days of endless chewing. There has been disagreement among experts on the issue. [Source: Ian Sample, The Guardian, August 22, 2011]

Richard Wrangham, a British evolutionary biologist at Harvard, claimed that harnessing fire to cook food was instrumental in the rise of modern humans in his 2010 book “Catching Fire: How Cooking Made Us Human.” Nicholas Mott wrote in National Geographic: “Applying fire to food also softens tough fibers, releases flavors, and speeds up the process of chewing and digesting. The extra nutrition, and the improved eating experience, allowed our prehistoric ancestors to spend less time searching for food—and less time chewing through tough plants for meager caloric reward. Cooking, therefore, gave us both the nutrition we needed to develop large brains and the time we needed to use them for things more interesting than chewing. [Source: Nicholas Mott, National Geographic, October 26, 2012]

According to Discovery.com: “Anthropologists think early humans began using fire to cook foods some 1.8 million years ago. Though the archaeological evidence is sparse, some scientists adopt this time frame and support that cooking may have lifted the energetic constraints that allowed humans to develop larger brains. Cooking meats may have allowed people to preserve food longer as well as save the immune system the trouble of fighting off certain foodborne pathogens that are killed by the cooking process.” [Source: news.discovery.com, November 9, 2011]

Richard Wrangham’s Cooking Hypothesis

In 1999, Richard Wrangham, an influential primatologist at Harvard, proposed a theory of human origins called the “cooking hypothesis.” Kenneth Miller wrote in Discover: Wrangham aimed to fill a gap in the story of how early hominins like Australopithecus — essentially, apes that walked upright — evolved into modern Homo sapiens. Evolutionary science shows that our distant progenitors became bipedal 6 million to 7 million years ago. [Source: Kenneth Miller, Discover, December 17, 2013 /+]

Archaeologists believe early hominins evolved bigger brains as they walked, took up hunting and developed more complex social structures. That process led to the emergence of Homo habilis, the first creature generally regarded as human, 2.3 million years ago. Yet H. habilis’ brain was only moderately larger than Australopithecus’, and its body retained many apelike features. No one knows why, just 500,000 years later, a radically more advanced species — Homo erectus — emerged. Its brain was up to twice the size of its predecessor’s, its teeth were much smaller, and its body was quite similar to ours. /+\

“Wrangham credits the transformation to the harnessing of fire. Cooking food, he argues, allowed for easier chewing and digestion, making extra calories available to fuel energy-hungry brains. Firelight could ward off nighttime predators, allowing hominins to sleep on the ground, or in caves, instead of in trees. No longer needing huge choppers, heavy-duty guts or a branch swinger’s arms and shoulders, they could instead grow mega-craniums. The altered anatomy of H. erectus, Wrangham wrote, indicates that these beings, like us, were “creatures of flame.” There was one major problem with this hypothesis, however: Proving it would require evidence of controlled fire from at least 1.8 million years ago, when the first H. erectus appeared./+\

Reasoning Behind Richard Wrangham’s Cooking Hypothesis

Richard Wrangham

L.V. Anderson wrote on Slate.com: “This hypothesis stems from a few modern observations. When you eat cooked food, you have access to many more calories than if you eat the same food raw. There are two reasons: Our digestive systems can extract more calories from a cooked steak (for instance) than a raw steak, and it takes much less energy to cook and eat a steak than to gnaw on a raw one for hours. Access to cooked food means a hominin no longer needs enormous teeth to break down all that raw meat and roughage into swallowable hunks, nor does it need as robust a digestive system to process it all. The combination of more calories and less complicated intestines means more energy can be devote to cogitating—hence H. erectus’ relatively big brains, which suck up a lot of calories. As evidence for his theory, Wrangham likes to point to the fact that modern-day humans can’t thrive on an all-raw diet—raw foodists tend to stop menstruating, precluding reproduction. [Source: L.V. Anderson, Slate.com, October 5, 2012 \~/]

In his book “Catching Fire: Cooking Up a Pot of Civilization”, Jane Black wrote in the Washington Post, Richard Wrangham “argues that cooking, not meat-eating or social interdependence, is what differentiates us from other animals. Almost 2 million years ago cooked food helped a new species, homo erectus, with its large brain and small gut, emerge. And cooking is responsible for the development of agrarian societies, traditional gender roles and division of labor. In short, without a hot dinner, we would still be apes. [Source: Jane Black, Washington Post, July 12, 2009 +++]

“Wrangham is not the first to connect cooking to evolution; Jean-Anthelme Brillat-Savarin, the French gastronomist, suggested as much when he wrote in 1825: "It is by fire that man has tamed Nature itself." But Wrangham draws together previous studies and theories from disciplines as diverse as anthropology, biology, chemistry, sociology and literature into a cogent and compelling argument. +++

“Take the issue of digestion. Wrangham makes the case that our ability to heat food and thereby soften it spares our bodies a lot of hard work. And the calories saved in easy digestion reserve energy for other types of physical and intellectual activity. To understand why, simply consider how you feel after eating a light meal versus a heavy one. That shrimp salad demands less work from your intestines and makes you feel energetic afterwards; the 16-ounce steak makes you want to take a nap while your body attacks and breaks down the meal. The same differences apply to softer, cooked food versus raw, unprocessed food. +++

“Softer food can be eaten more quickly than raw food, and that fact has allowed the human species to reallocate the way it spends its time. In the Western world, men and women each spend an average of five percent of their time chewing, about 36 minutes in a 12-hour day, Wrangham reports. Raw food, in contrast, must be chewed longer. For a human being to eat the same diet as a great ape, researchers estimate that we would have to dedicate 42 percent or five hours simply to breaking down our food. +++

“With more free time, societies developed. Male hunters went farther afield in search of a prize, confident that they could get enough calories in a short time from cooked grains, nuts and berries collected by the community's gatherers. Women were bound to the fire. "Cooking freed women's time and fed their children but it also trapped women into a newly subservient role enforced by male-dominated culture," Wrangham writes. "Cooking created and perpetuated a novel system of male cultural superiority."” +++

Book “Catching Fire: Cooking Up a Pot of Civilization” by Richard Wrangham (Basic, 2009)

Critics of Richard Wrangham’s Cooking Hypothesis

L.V. Anderson wrote on Slate.com: “There’s one problem with Wrangham’s elegant hypothesis: It’s hardly the scientific consensus. In fact, since 2009, when Wrangham explained his theory in the book Catching Fire, several archaeologists have come forward with their own, wildly divergent opinions about what is arguably the oldest intellectual property debate in the world. Who really mastered fire, in the sense of being able to create it, control it, and cook with it regularly? Was it Homo erectus, Neanderthals, or modern humans? [Source: L.V. Anderson, Slate.com, October 5, 2012 \~/]

Wrangham’s theory is elegant, but the archaeological record is a little more complicated. There is definitely evidence of fire around 1.6 million years ago in what is now Kenya. But archaeologists dispute whether this was manmade or natural fire. Further complicating Wrangham’s hypothesis is evidence that hominins may not have brought fire with them when H. erectus moved out of Africa into Europe around a million years ago. If fire was as transformative and beneficial as Wrangham said it was, you’d think our ancestors would have brought it with them when they moved to colder climes—or died out if they were unable to do so.

Nicholas Mott wrote in National Geographic: “ Proponents of raw-food diets don’t prepare their meals at all. Like the gorilla, they simply munch away on raw fruits and vegetables. Why? Some of them believe that heating food over 40 degrees Fahrenheit (4 degrees Celsius) destroys natural enzymes present in plants—molecular structures that help us digest proteins missing in processed foods. Others consider a retrogressive diet more environmentally sound, citing the various problems caused by modern industrial food production and distribution. And some folks simply eat raw foods as a quick way to shed a few pounds. [Source: Nicholas Mott, National Geographic, October 26, 2012]

“But “if you’re healthy, this is a terrible idea,” said Herculano-Houzel. “Sure, you’ll lose weight very fast—you’ll be eating all day and still feel starved.” That’s because the low nutritional yield from raw foods requires massive consumption. In other words, if you want to sustain an active lifestyle, eating raw foods takes time and energy of its own. Besides, said Herculano-Houzel, cooked food simply tastes better. “Even apes, when offered a choice of raw food or spaghetti and meatballs, will take the meatballs every time.”“

Cooking 1.9 Million Years Old?

Based on a studies of tooth sizes and the feeding behaviour of monkeys, apes and modern humans, Harvard scientists suggest that cooking was commonplace among Homo erectus and probably originated early, around 1.9 million years ago.Ian Sample wrote in The Guardian: The scientists “concluded that cooking was commonplace among Homo erectus, and probably originated early in that species' reign, if not before in more primitive humans. "This is part of an emerging body of science that shows cooking itself is important for our biology; that is, we are biologically adapted for cooking food," said Chris Organ, an evolutionary biologist at Harvard. [Source: Ian Sample, The Guardian, August 22, 2011 |=|]

“The researchers began by creating an evolutionary tree of monkeys, apes and modern humans. On to this they added information on how long various species spent feeding. Compared with chimpanzees, our closest living relatives, humans spent remarkably little time eating. Chimps typically spent more than one third of their day feeding, while for humans it was about 5 percent of their waking hours. |=|

“The scientists then added information on tooth sizes to the family tree, and this time they included details of extinct human ancestors and closely related species. The study showed that three species of humans, Homo erectus, Neanderthals (Homo neanderthalensis), and modern humans (Homo sapiens), evolved small molars relatively quickly, which could not be explained by general changes in head and jaw sizes. |=|

“Instead, the scientists believe the invention of cooking could explain the changes in both tooth size and feeding times. As early humans learned how to cook, they no longer needed large back teeth to chew tough food, or had to spend hours chewing to gain enough calories. Over time, large teeth disappeared from our ancestors, to be replaced with far smaller ones. |=|

“According their report in the US journal Proceedings of the National Academy of Sciences, Homo erectus, which emerged in Africa around 1.9 million years ago, spent 6.1 percent of its time eating. Neanderthals, the authors claim, spent 7 percent of their time feeding. "We think that Homo erectus and Neanderthals were spending about as much of their day feeding as we do, which implies that they were both cooking," Organ said. |=|

“More primitive species, such as Homo habilis and Homo rudolfensis, which emerged before Homo erectus and the Neanderthals, spent 7.2 percent and 9.5 percent of their day eating. If the estimates are right, it suggests they may have been less accomplished cooks than Homo erectus and the Neanderthals. |=|

Study of Gorillas Shows Why Cooking Gave Hominins Bigger Brains

Gorillas have to forage and eat for 8.8 hours a day or more. This, scientists suggest, shows how cooking gave humans spare energy for brain growth. Maev Kennedy wrote in The Guardian: Research into these matters “explains why great apes such as gorillas, which can have bodies three times the size of humans, have considerably smaller brains. Though gorillas typically spend up to eight hours feeding, their diet influenced an evolutionary tradeoff between body and brain size; supporting both big bodies and big brains would be impossible on a raw food diet. [Source: Maev Kennedy, The Guardian. October 22, 2012]

“The brain is so energy-hungry that in humans it represents 20 percent of the resting metabolic rate, even though it only represents 2 percent of body mass, suggest Professor Suzana Herculano-Houzel and Karina Fonseca-Azevedo of the Institute of Biomedical Sciences at the Federal University of Rio de Janeiro. "Why are the largest primates not those endowed with the largest brains as well? Rather than evidence that humans are an exception among primates, we consider this disparity to be a clue that, in primate evolution, developing a very large body and a very large brain have been mutually excluding strategies, probably because of metabolic reasons." |=|

“Gorillas, they suggest, already live on the limit of viability, foraging and eating for 8.8 hours a day, and in extreme conditions increasing this to as much as 10 hours a day. In contrast, humans' move to a cooked diet, possibly first adopted by Homo erectus, and their bigger brains yet smaller bodies, left spare energy which allowed further rapid growth in brain size and the chance to develop the big brain as an asset rather than a liability, through expanded cognitive capacity, flexibility and complexity. "We propose that this change from liability to asset made possible the rapid increase in brain size that characterises the evolution of Homo species, leading to ourselves. We may thus owe our vast cognitive abilities to the invention of cooking – which, to my knowledge, is by far the easiest and most obvious answer to the question, what can humans do that no other species does?" Herculano-Houzel commented on the paper, published in the journal PNAS, the Proceedings of the Natural Academy of Sciences of the USA. |=|

“The paper builds on the earlier research by Richard Wrangham, who said he hoped later work would look at tradeoffs within the body allowing energy from smaller organs to be diverted to the brain – for instance our relatively small guts. "Human guts are about 60 percent of the expected size for a primate. The small size of human guts (combined with our having the same basal metabolic rate as any other primate, relative to body mass) means that we have some spare energy, which contributes to explaining how we can afford a relatively large brain. And the reason we have been able to evolve small guts is that we have been able to rely on eating our food cooked."” |=|

Mice Experiment Shows Cooked Meat Provides More Energy Than Raw Meat

Discovery.com reported: “For years, scientists have thought cooked foods are easier to digest, and thus, are more nutritious than non-cooked eats. Before now, though, they lacked the evidence needed to confirm these claims for meat. But a recent experiment suggests that cooked meat packs more nutritional value than its raw counterpart. The findings could give clues to how early humans gained more energy from cooking meats as well as provide insight on ways to maximize nutrition today. [Source: news.discovery.com, November 9, 2011]

“The researchers tested foods in the ways that they’re actually digested in organisms, rather than analyzed outside of the body. The experiment involved feeding groups of mice variations of organic beef or sweet potatoes over a 40-day period. Different diets included raw/intact, raw/pounded, cooked/intact and cooked/pounded foods (either the beef or the sweet potato). Mice could eat food freely, and researchers monitored the rodents’ activity levels and body mass. While activity didn’t differ across groups, body mass did. All mice lost weight on the diets, but those consuming cooked foods lost less than others eating raw foods. This means that the mice were getting more energy from the cooked foods, especially the meat.

“The paper’s authors think a few mechanisms might be at play. First, cooking seems to unwind proteins in meat, which could make it easier to digest in the small intestine before gut bacteria take their share of the pie. In addition, cooking meat seems to loosen muscle fiber connections, making the foods easier to chew. The way foods are prepared — whether they’re pounded, crushed, sliced, and so on — also matters. Pounded foods appeared to provide more energy, but not as much as cooking. Yet while pounding breaks down the structure of food fibers, it doesn’t have as much of an effect on cells at the molecular level. This is where cooking has the advantage. Incorporating both cooking and pounding produced the best results.”

Debate about Which Hominins First Started Cooking

L.V. Anderson wrote on Slate.com: “According to Wrangham, H. erectus must have had fire—just look at their anatomy! H. erectus had smaller jaws and teeth (and smaller faces in general), shorter intestinal tracts, and larger brains than even earlier hominins, such as Australopithecus afarensis, for instance, who were boxier, more apelike, and probably duller. Wrangham argues that H. erectus would not have developed its distinctive traits if the species hadn’t been regularly eating softer, cooked food. [Source: L.V. Anderson, Slate.com, October 5, 2012 \~/]

“If H. erectus didn’t bring fire mastery to Europe, who did? Archaeologists Wil Roebroeks of Leiden University in the Netherlands and Paola Villa of the University of Colorado Museum found evidence for frequent use of fire by European Neanderthals between 400,000 and 300,000 years ago. Roebroeks and Villa looked at all the data collected at European sites once inhabited by hominins and found no evidence of fire before about 400,000 years ago—but plenty after that threshold. Evidence from Israeli sites put fire mastery at about the same time. H. sapiens arrived on the scene in the Middle East and Europe 100,000 years ago, but our species didn’t have a discernible impact on the charcoal record. Roebroeks and Villa conclude that Neanderthals must have been the ones who mastered fire. \~/

“One of the beautiful things about the archaeological record is that archaeologists are always willing to debate about it. Attributing fire to Neanderthals is an overly confident reading of the evidence, according to archaeologist Dennis Sandgathe of British Columbia’s Simon Fraser University. Of course the number of campsites with evidence of fire increased between 1 million and 400,000 years ago, he says—the number of campsites, period, increased during this time in proportion with population growth. But that doesn’t mean the use of fire was universal among European hominins—there are plenty of Neanderthal campsites out there that show little or no evidence of fire, and Sandgathe has personally excavated some of them. What’s more, Sandgathe told me when I asked him about Roebroeks’ and Villa’s data, “We actually have better data than they do when it comes to Neanderthal use of fire.” \~/

“According to Sandgathe and his colleagues, hominins didn’t really master fire until around 12,000 years ago—well after Neanderthals had disappeared from the face of the planet (or merged into the human gene pool via interbreeding, depending on your view). Sandgathe and his colleagues excavated two Neanderthal cave sites in France and found, surprisingly, that the sites’ inhabitants used hearths more during warm periods and less during cold periods. Why on earth would Neanderthals not build fires when it was freezing outside? In “On the Role of Fire in Neandertal Adaptations in Western Europe: Evidence from Pech de l’Aze´ IV and Roc de Marsal, France,” Sandgathe advances the hypothesis that European Neanderthals simply didn’t know how to make fire. All they could do was harvest natural fires—those caused by lightning, for instance—to occasionally warm their bodies and cook their food. (This explains why Sandgathe found more evidence of fire from warm periods: Lightning is far less common during cold spells.) \~/

“Roebroeks and Villa think Sandgathe’s reasoning is flawed: After all, there isn’t evidence of fire at every modern human campsite, either, when you look at sites from the Upper Paleolithic period, which concluded about 10,000 years ago. “However, nobody would argue that Upper Paleolithic hunter-gatherers were not habitual users of fire,” they wrote in a response to Sandgathe et al.’s criticism of their work. Wrangham, meanwhile, thinks both Sandgathe et al. and Roebroeks et al. ignore some critical nonarchaeological evidence: his point that contemporary humans can’t survive on a diet of uncooked food. Accepting Sandgathe’s hypothesis, Wrangham wrote in an email, “means that the contemporary evidence is wrong, or that humans have adapted to need cooked food only in the last 12,000 years. Both suggestions are very challenging!” \~/

Difficulty Studying Early Fire Use and Cooking

L.V. Anderson wrote on Slate.com: “Why on earth can’t scientists agree on whether people mastered fire 1.8 million years ago or 12,000 years ago? That’s a 150-fold difference. Well, figuring out who burned what, when, is not an easy business. For one thing, archaeologists can’t always tell what caused a fire: a volcano, for instance, a lightning strike, or hominin ingenuity. And even if there is clear evidence of hominin fire use—a hearth at a formerly inhabited cave, for instance—it’s almost impossible to tell whether it was created by people from scratch or merely stolen from a natural fire and then transported to a hearth, where it was kept alive as long as possible. Scientists call this kind of fire use opportunistic. [Source: L.V. Anderson, Slate.com, October 5, 2012 \~/]

“What’s more, even when people were creating fires, the evidence of said fires doesn’t always stay put. Ashes have a tendency to blow away instead of embedding themselves neatly in the archaeological record, while water can take evidence of fire from its original location and carry it someplace completely different. Then there’s human error: As Sandgathe et al. write in their discussion of the available evidence, “There are … examples where residues originally interpreted as the remains of fires are later identified as something else.” (I hate it when that happens.) At one site in China, for instance, layers of earth originally believed to be ashes were later revealed to be silt and unburned bits of organic matter. \~/

“Archaeological methods are improving, and they may well end up bearing out Wrangham’s hypothesis. In a paper published earlier this year, archaeologists used advanced techniques (known as micromorphological and Fourier-transform infrared microspectroscopy) to examine sediment and reveal evidence of fire at a million-year-old South African cave site. \~/

“Wrangham is also hopeful that other disciplines will provide evidence for his theory. “I suspect genetics will help,” he says. “If we can pin down the genes underlying the adaptation to cooked food, we may be able to date the control of fire close enough to settle the big question.” “Sure, that would be pretty compelling evidence,” admits Sandgathe. But he’s hopeful that genetics will bolster his hypothesis: that Neanderthals survived frigid glacial periods not because they regularly used fire, but because they had thick body hair. “At some point someone may announce the discovery of the gene or genes that code for thickness of body hair, and so could answer that question,” he says. \~/

“Judging from the way things are going, this debate may rage on for a good while longer. And there is room for more than one right answer: It’s possible that different groups mastered fire independently of one another at different points in time. But laypeople can take comfort in knowing that, even if we don’t know yet who first mastered fire—our simple ancestors almost 2 million years ago, our more advanced cousins 400,000 years ago, or our direct antecedents about 10,000 years ago—there’s no doubt who holds the intellectual property rights to it today. We even put it in an oven and made it our own.” \~/

Cooked Food Versus Raw Food

Ann Gibbons wrote in National Geographic: “The latest clue as to why our modern diet may be making us sick comes from Harvard primatologist Richard Wrangham, who argues that the biggest revolution in the human diet came not when we started to eat meat but when we learned to cook. Our human ancestors who began cooking sometime between 1.8 million and 400,000 years ago probably had more children who thrived, Wrangham says. Pounding and heating food “predigests” it, so our guts spend less energy breaking it down, absorb more than if the food were raw, and thus extract more fuel for our brains. “Cooking produces soft, energy-rich foods,” says Wrangham. Today we can’t survive on raw, unprocessed food alone, he says. We have evolved to depend upon cooked food. [Source: Ann Gibbons, National Geographic, September 2014 /*/]

“To test his ideas, Wrangham and his students fed raw and cooked food to rats and mice. When I visited Wrangham’s lab at Harvard, his then graduate student, Rachel Carmody, opened the door of a small refrigerator to show me plastic bags filled with meat and sweet potatoes, some raw and some cooked. Mice raised on cooked foods gained 15 to 40 percent more weight than mice raised only on raw food. /*/

“If Wrangham is right, cooking not only gave early humans the energy they needed to build bigger brains but also helped them get more calories from food so that they could gain weight. In the modern context the flip side of his hypothesis is that we may be victims of our own success. We have gotten so good at processing foods that for the first time in human evolution, many humans are getting more calories than they burn in a day.”

Image Sources: Wikimedia Commons except Wonderwerk Cave, University of Toronto and Wonderwerkcave.com and Richard Wrangham, Harvard University

Text Sources: National Geographic, New York Times, Washington Post, Los Angeles Times, Smithsonian magazine, Nature, Scientific American. Live Science, Discover magazine, Discovery News, Ancient Foods ancientfoods.wordpress.com ; Times of London, Natural History magazine, Archaeology magazine, The New Yorker, Time, Newsweek, BBC, The Guardian, Reuters, AP, AFP and various books and other publications.

Last updated September 2018