4 December 2014 - FIRE


FIRE

G'day folks,

Ever wonder when fire was first used? Read on ...


The discovery of fire, or, more precisely, the controlled use of fire was, of necessity, one of the earliest of human discoveries. Fire's purposes are multiple, some of which are to add light and heat, to cook plants and animals, to clear forests for planting, to heat-treat stone for making stone tools, to keep predator animals away, to burn clay for ceramic objects. Undeniably, there are social purposes as well: as gathering places, as beacons for those away from camp, as spaces for special activities.


The human control of fire likely required a cognitive ability to conceptualize the idea fire, which itself has been recognized in chimpanzees; great apes have been known to prefer cooked foods, so the very great age of the earliest human fire experimentation should not come as a terrific surprise. 



Discovery of Fire


The controlled use of fire was likely an invention of our ancestor Homo erectus, during the Early Stone Age (or Lower Paleolithic). The earliest evidence for fire associated with humans comes from Oldowan hominid sites in the Lake Turkana region of Kenya. The site known as Koobi Fora (FxJj20, dated 1.6 million years ago) contained oxidized patches of earth to a depth of several centimeters, which some scholars interpret as evidence for fire control. At 1.4 million years of age, the Australopithecine site of Chesowanja in central Kenya also contained burned clay clasts, in small areas.


Other Lower Paleolithic sites in Africa that contain possible evidence for fire include Gadeb in Ethiopia (burned rock), and Swartkrans (270 burned bones out of a total of 60,000, dated 600,000-1 million years old), and Wonderwerk Cave (burned ash and bone fragments, ca. 1 million years ago) in South Africa.


The earliest evidence for controlled use of fire outside of Africa is at the Lower Paleolithic site of Gesher Benot Ya'aqov in Israel, where charred wood and seeds were recovered from a site dated 790,000 years ago. The next oldest site is at Zhoukoudian, a Lower Paleolithic site in China dated to about 400,000 BP, Beeches Pit in the UK at about 400,000 years ago, and at Qesem Cave (Israel), between about 200,000-400,000 years ago.


In a paper published in Nature in March 2011, Roebroeks and Villa report their examinations of the available data for European sites and concluded that habitual use of fire wasn't part of the human (meaning early modern and Neanderthal both) suite of behaviors until ca. 300,000 to 400,000 years ago. They argue that the earlier sites are representative of opportunistic use of natural fires.



Indirect Evidence


In 2013, Terrence Twomey published a paper in the Cambridge Archaeological Journal, which included a comprehensive discussion of the early evidence for human-controlled fire at 400,000-800,000 years ago, citing Gesher and the newly revised dates for Zhoukoudien level 10 (780,000-680,000 years ago). Twomey agrees with Roebroeks and Villa that there is no direct evidence for domestic fires between 400,000 and 700,000 years ago, but believes that other, indirect evidence supports the notion of controlled use of fire.


Twomey's argument is based several lines of indirect evidence. First, he cites the metabolic demands of relatively big-brained Middle Pleistocene hunter-gatherers, and suggests that brain evolution required cooked food. Further, he argues that our distinctive sleep patterns (staying up after dark) are deeply rooted; and that hominids began staying in seasonally or permanently cool places by 800,000 bp. All of this, says Twomey, implies effective control of fire. 



 The Cooking Hypothesis


One additional evidence for the early use of fire is the reduction of the size of mouth, teeth and digestive system, which are striking in Homo erectus, compared to earlier ancestors. The benefits of having a smaller gut could not be realized, goes the theory, until high-quality foods were available all year long. The adoption of cooking, which softens food and makes it easier to digest, could have led to these changes. See Gowlett and Wrangham for a discussion.


Hearth Fire Construction


As opposed to fire, a hearth is a deliberately constructed fireplace. The earliest fireplaces were made by collecting stones to contain the fire, or simply reusing the same location again and again and allowing the ash to act as hearth construct. Those are found in the Middle Paleolithic period (ca 200,000-40,000 years ago, at sites such as Klasies River Caves (South Africa, 125,000 years ago) , Tabun Cave (at Mt. Carmel, Israel), and Bolomor Cave (Spain, 225,000-240,000 years ago).


Earth ovens, on the other hand, are hearths with banked and sometimes domed structures built of clay. These types of hearths were first used during the Upper Paleolithic (ca 40,000-20,000 years BP), for cooking, heating and, sometimes, to burn clay figurines to hardness. The Gravettian Dolni Vestonice site in the modern Czech Republic has evidence of kiln construction, although construction details did not survive. The best information on Upper Paleolithic kilns is from the Aurignacian deposits of Klisoura Cave in Greece (ca 32,000-34,000 years ago).



Fuels


Relict wood was likely the fuel used for the earliest fires. Purposeful selection of wood came later: hardwood such as oaks burns differently from softwood from pines, the moisture content and density of a wood all affect how hot or how long a fire burns. Other sources became important in various places with limited wood supply, because when timber and branch wood was needed for structures, furnishing and tools would have reduced the amount of wood spent on fuel.


If wood was not available, alternative fuels such as peat, cut turf, animal dung, animal bone, seaweed, and straw and hay can be used in a fire. Animal dung was likely not consistently used until after animal domestication led to the keeping of livestock, about 10,000 years ago.


But of course, everyone knows that Prometheus stole fire from the gods, the Greek myth as reported by our Ancient History expert.



Clancy's comment:  Amazing, eh? Like most things we have, they can be helpful and also harmful.

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