Control of fire by early humans

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A reconstruction of Homo erectus. Anthropologists believe that H. erectus was the first hominid to control fire.
A reconstruction of Homo erectus. Anthropologists believe that H. erectus was the first hominid to control fire.

The control of fire by early humans was a turning point in human cultural evolution that allowed for humans to proliferate due to the incorporation of cooked proteins and carbohydrates, expansion of human activity into the night hours, and protection from predation.[1]

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[edit] Evidence

[edit] East Africa

The earliest evidence of human usage of fire comes from various archaeological sites in East Africa, such as Chesowanja near Lake Baringo, Koobi Fora, and Olorgesailie in Kenya. The evidence at Chesowanja consists of red clay sherds dated to be 1.42 Ma BP.[2] Reheating on the sherds found at the site show that the clay must have been heated to 400°C to harden.

At Koobi Fora, sites FxJjzoE and FxJj50 show evidence of control of fire by Homo erectus at 1.5 Ma BP, with the reddening of sediment that can only come from heating at 200—400°C.[2]

Olorgesailie, Kenya, has a site that has a hearth-like depression but no sign of charcoal. Some microscopic charcoal was found, but it is argued that it could have come from a natural brush fire.[2]

In Gadeb, Ethiopia, fragments of welded tuff that appeared to have been burned were found in Locality 8E, but re-firing of the rocks may have occurred due to local volcanic activity.[2] These have been found amongst H. erectus created Acheulean artifacts.

In the Middle Awash River Valley, cone-shaped depressions of reddish clay were found that could be created by temperatures of 200°C. These features are thought to be burned tree stumps such that they would have fire away from their habitation site.[2] Burnt stones are also found in the Awash Valley, but volcanic welded tuff is also found in the area.

[edit] South Africa

The earliest definitive evidence of human control of fire was found at Swartkrans, South Africa. Several burnt bones were found among Acheulean tools, bone tools, and bones with hominid-inflicted cut marks.[2] This site also shows some of the earliest evidence of carnivory in H. erectus. The Cave of Hearths in South Africa has burned deposits dated from 0.2 to 0.7 Ma BP, as do various other sites such as Montagu Cave (0.058 to 0.2 Ma BP) and at the Klasies River Mouth (0.12 to 0.13 Ma BP).[2]

The strongest evidence comes from Kalambo Falls in Zambia where several artifacts related to the use of fire by humans had been recovered including charred logs, charcoal, reddened areas, carbonized grass stems and plants, and wooden implements which may have been hardened by fire. The site was dated through radiocarbon dating to be at 61,000 BP and 110,000 BP through amino acid racemization.[2]

[edit] Near East

A more recently discovered site at Gesher Benot Ya'aqov, Israel, shows H. erectus or H. ergaster fires made between 790 and 690 ka BP.[3]

[edit] Far East

In Xihoudu in Shanxi Province, there is evidence of burning by the black, gray, and grayish-green discoloration of mammalian bones. Another site in China is Yuanmou in Yunnan Province, where blackened mammal bones have been found.[2]

At Trinil, Java, similar blackened bone and charcoal deposits have been found among H. erectus fossils.

[edit] Zhoukoudian

Zhoukoudian Caves, a World Heritage Site in China.
Zhoukoudian Caves, a World Heritage Site in China.

At Zhoukoudian in China, evidence of fire is as old as 500,000 to 1.5 million BP.[4] Fire in Zhoukoudian is suggested by the presence of burned bones, burned chipped-stone artifacts, charcoal, ash, and hearths alongside H. erectus fossils in Layer 10 at Locality 1.[2][5] This evidence comes from Locality 1 at Zhoukoudian where several bones were found to be uniformly black to grey. The extracts from the bones were determined to be characteristic of burned bone rather than manganese staining. These residues also showed IR spectra for oxides, and a bone that was turquoise was reproduced in the laboratory by heating some of the other bones found in Layer 10. At the site, the same effect may have been due to natural heating, as the effect was produced on white, yellow, and black bones.[5] Layer 10 itself is described as ash with biologically produced silicon, aluminum, iron, and potassium, but wood ash remnants such as siliceous aggregates are missing. Among these are possible hearths "represented by finely laminated silt and clay interbedded with reddish-brown and yellow brown fragments of organic matter, locally mixed with limestone fragments and dark brown finely laminated silt, clay and organic matter."[5] The site itself does not show that fires were made in Zhoukoudian, but the association of blackened bones with stone artifacts at least shows that humans did control fire at the time of the habitation of the Zhoukoudian cave.

[edit] Europe

Multiple sites in Europe have also shown evidence of use of fire by H. erectus. The oldest has been found in Vertesszollos, Hungary, where evidence of burned bones but no charcoal had been found. At Torralba and Ambrona, Spain, show charcoal and wood, Acheulean stone tools dated 0.3 to 0.5 Ma BP.[2]

At St. Estève-Janson in France, there is evidence of five hearths and reddened earth in the Escale Cave. These hearths have been dated to 200 ka BP.[2]

The mean evidence states that widespread control of fire began 125,000 BP.[4]

[edit] Changes to behavior

One of the primary changes to the behavior of humans due to the control of fire was the utilization of the light.[6] With the light from fires, the activity was no longer restricted to the day time. In addition, animals in general avoid fire and smoke.[1][2] Another change that fire provided was the opening of the nutrition in cooked proteins.[1][5][7]

Richard Wrangham of Harvard University argues that cooking of plant foods may have triggered brain expansion by allowing complex carbohydrates in starchy foods to become more digestible and in effect allow humans to absorb more calories.[8][9][10]

[edit] Changes to diet

Stahl suggested that because of the indigestible components of plants such as raw cellulose and starch, certain parts of the plant such as stems, mature leaves, enlarged roots, and tubers would not have been part of the hominid diet prior to the advent of fire.[11] Instead, the diet consisted of the parts of the plants that were made of simpler sugars and carbohydrates such as seeds, flowers, and fleshy fruits. The incorporation of toxins into the seeds and similar carbohydrate sources also affected the diet, as cyanogenic glycosides such as those found in linseed, cassava, and manioc are made non-toxic through cooking.[11] The teeth of H. erectus and the wear on the teeth reflect the consumption of foods such as tough meats and crisp root vegetables.[12][13]

The cooking of meat, as evident from burned and blackened mammal bones, makes the meats easier to eat and easier to attain the nutrition from proteins by making the meat itself easier to digest.[14][15] The amount of energy needed to digest cooked meat is less than raw meat, and cooking gelatinizes collagen and other connective tissues as well as "opens up tightly woven carbohydrate molecules for easier absorption."[15]

[edit] References

  1. ^ a b c Price, David. Energy and Human Evolution. Retrieved on 2007-11-12.
  2. ^ a b c d e f g h i j k l m James, Steven R. (February 1989). "Hominid Use of Fire in the Lower and Middle Pleistocene: A Review of the Evidence". Current Anthropology 30 (1): 1–26. University of Chicago Press. doi:10.1086/203705. 
  3. ^ Rincon, Paul. "Early human fire skills revealed", BBC News, April 29, 2004. Retrieved on 2007-11-12. 
  4. ^ a b First Control of Fire by Human Beings--How Early?. Retrieved on 2007-11-12.
  5. ^ a b c d Weiner, S.; Q. Xu, P. Goldberg, J. Liu, O. Bar-Yosef (1998). "Evidence for the Use of Fire at Zhoukoudian, China". Science 281: 251–253. doi:10.1126/science.281.5374.251. 
  6. ^ Stone, Linda; Paul F. Lurquin, Luigi Luca Cavalli-Sforza. Genes, Culture, And Human Evolution: A Synthesis. Blackwell Publishing, 33. 
  7. ^ Eisley, Loren C. (1955). "Fossil Man and Human Evolution". Yearbook of Anthropology: 61–78. University of Chicago Press. 
  8. ^ William R. Leonard. Food for Thought: Into the Fire. Scientific american. Retrieved on 2008-02-22.
  9. ^ Wrangham R, Conklin-Brittain N. (2003 Sep). "Cooking as a biological trait". Comp Biochem Physiol A Mol Integr Physiol 136 (1): 35–46. doi:10.1016/S1095-6433(03)00020-5. PMID 14527628. 
  10. ^ Lambert, Craig. "The Way We Eat Now", Harvard Magazine, May-June 2004. 
  11. ^ a b Stahl, Ann Brower (April 1984). "Hominid Dietary Selection Before Fire". Current Anthropology 25 (2): 151–168. University of Chicago Press. doi:10.1086/203106. 
  12. ^ Viegas, Jennifer. "News in Science - Homo erectus ate crunchy food - 22/11/2005", November 22, 2005. Retrieved on 2007-11-12. 
  13. ^ Early Human Evolution:  Homo ergaster and erectus. Retrieved on 2007-11-12.
  14. ^ What evidence is there that Homo erectus used fire? Why did they use it?. Retrieved on 2007-11-12.
  15. ^ a b Gibbons, Ann. "Food for Thought" (pdf). Science. 

[edit] See also