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paleoanthropology, genetics and evolution

Gesher Benot Ya'aqov

  • Did humans colonize the northern latitudes without fire?

    Mon, 2011-03-14 20:47 -- John Hawks

    Wil Roebroeks and Paola Villa [1] review the evidence for human control and use of fire in the archaeology of Europe during the Middle Pleistocene (130,000-780,000 years ago) and earlier. They observe that no evidence of human-controlled fire occurs in Europe before 400,000 years ago. This raises a puzzle: How did humans occupy the northern part of Europe without fire?

    The argument about the antiquity of fire is not new. There is very early evidence of fire at Swartkrans, Koobi Fora, and Chesowanja, which includes burned bones and heated artifacts, along with clay nodules that show evidence of heating as high as 400 degrees Celsius. The criticism of these early finds (reviewed by James [2]) centers around the difficulty of distinguishing human-made fire from natural bush fires. The association of the fire with artifacts can be readily explained: archaeologists only look for evidence of fire where they already have artifacts. The remaining question is whether artifacts or bones have been heated to temperatures hotter than those possible in bush fires, thereby providing evidence of human involvement. Burned bone from Swartkrans at least did reach such temperatures, seemingly unlikely without human involvement given their presence in the cave. I tend to think that humans did control fire early in some cases.

    Roebroeks and Villa do not dispute possible earlier evidence of fire, but claim that it was not habitual. Or to put it another way, some early humans may have used fire, but many or most did not do so. The lack of fire seems particularly surprising in the northern latitudes of Europe, where sites like Happisburgh (and Pakefield) show evidence of human habitation in the late Lower Pleistocene. Their review of the early sites is really worth reading and impressively compact. Nonetheless, I can't quote it in full; it's just too much text to extract. After a discussion of the earliest archaeological occurrences, they turn to the long sequences from Arago and Gran Dolina, where we really should expect to see some evidence of fire if people were using it.

    Arago and Gran Dolina contain long sequences and large quantities of lithic and faunal remains, subjected to taphonomic analyses (34–36). Their settings are comparable to the ones that, in later times, have often provided strong evidence of fire, such as Bau de l’Aubesier, Grotte XVI, and Lazaret in France; Bolomor Cave in Spain (Dataset S1); and Middle Paleolithic/Middle Stone age caves in Israel and in South Africa. Traces of fire have been found in the upper part of the sequence at Arago, in layers younger than 350 ka. No charcoal, no burnt bones, nor any other evidence of fire have been reported from any of the assemblages from the lower levels (dated to MIS 10–14). No charred bones or heated artifacts have been reported from the Gran Dolina sequence (TD4– TD10). Rare charcoal particles have been found in thin sections of the TD6 sediments, but these sediments originate from the exterior of the cave, and there is evidence of low-energy transport (37); thus, the charcoal may not be in situ. However, the high density of human, faunal, and lithic remains as well as their state of preservation and refitting studies (38, 39) clearly indicate an occupation in situ with little postdepositional disturbance. The absence of any heated material from the long sequences of Gran Dolina and Arago, both documenting hominin occupations over several hundred thousand years (36, 40), is striking. This is a strong pattern, which can be tested by future work at other hominin habitation sites. We suggest that the European record displays a strong signal, in the sense that, from ~400 to 300 ka ago, many proxies indicate a habitual use of fire, but from the preceding 700 ka of hominin presence in Europe, we have no evidence for fire use.

    One thing that really impressed me visiting Roc de Marsal last summer was that the site preserves a long archaeological sequence in which some levels are densely packed with charcoal and the remains of hearths, and at least one well-defined layer, with abundant evidence of tools and debitage, just has hardly any evidence of fire at all. These were Neandertals, not Middle Pleistocene Homo, and they managed to get by without leaving any clear evidence of fire even though many Neandertal populations clearly did control and use fire extensively, including at this very site at other times.

    There really were people living in the Pleistocene of Europe who didn't use fire very much, at least as evidenced by relatively long cultural deposits in well-stratified rock shelters and caves. Unfavorable preservation can explain the lack of charcoal or hearths at some sites, but not all of them. If we don't have a single good instance of fire in Europe before 400,000 years ago, people may well have done without it.

    The authors' review of fire evidence after 400,000 years ago in Europe is also very useful, and they include supplementary data table with fuller information and references for all the sites they discuss. It is impressive just how much evidence has accumulated over the years, and Roebroeks and Villa have doggedly tracked it down. They conclude that Neandertals had essentially the same degree of control of fire as Upper Paleolithic humans, and consider the use of fire as a processing step in the manufacture of complex tools:

    A recent study provides evidence of early modern humans at the site of Pinnacle Point in Southern Africa regular use of heat treatment to increase the quality and efficiency of their stone tool manufacture process 164 ka ago (13). The authors infer that the technology required a novel association between fire, its heat, and a structural change in stone with consequent flaking benefits that demanded “an elevated cognitive ability.” They also suggest that, when these early modern humans moved into Eurasia, their ability to alter and improve available raw material may have been a behavioral advantage in their encounters with the Neandertals. However, this interpretation ignores that Neandertals used fire as an engineering tool to synthesize birch bark pitch tens of thousands of years before some modern humans at Pinnacle Point decided to put their stone raw material in it. In more general terms, a greater control and more extensive use of fire is sometimes (12) seen as one of the behavioral innovations that emerged in Africa among modern humans and favored the spread of modern humans throughout the world. As stressed by Daniau et al. (52), if extensive fire use for ecosystem management were indeed a component of the modern human technical and cognitive package, one would expect to find major disturbances in the natural biomass burning variability associated with and after the colonization of Eurasia by modern humans. In their study of microcharcoal particles from two deep-sea cores off of Iberia and France, spanning the 70- to 10-ka period of biomass burning, the authors did not recover any sign that Upper Paleolithic humans made any difference: either Neandertals and modern humans did not affect the natural fire regime, or they did so in comparable ways.

    I do think the silcrete processing is interesting, but so is the pitch processing. For that matter, the possibility of fire-hardening in the Schoeningen spears would be a case of deliberate production of a complex tool using fire (complex, in that the fire-processing adds a step).

    Gesher Benot Ya'aqov, in Israel dating to around 800,000 years ago, is a highly compelling site in terms of evidence of fire. There are distinct hearth areas that correlate with archaeological scatter and have burned nut hulls and other foodstuffs. While Roebroeks and Villa express skepticism about the earlier evidence from Africa (specifically pointing to the high likelihood of bush fire as an explanation), they do accept Gesher Benot Ya'aqov as a likely fire location, while discussing the strength of the evidence. It's not such a high threshold to set; it seems like other sites should be able to meet it if fire was common.

    Personally, I am quite ready to accept that fire was invented many times by Lower Pleistocene humans and may have occurred in some regions of the world ephemerally. The maintenance of this tradition may have been a challenge that these early humans couldn't meet over long spans of time. This view does imply that the advantages of fire, including cooking, were not a typical part of the repertoire of Early Paleolithic people. But that would be consistent with what we understand of traditions in other species of primates; where one population may be pursuing complex and apparently valuable extractive foraging that another population lacks, despite otherwise being ecologically similar.


    References

    1. Roebroeks W, and Villa P. 2011. On the earliest evidence for habitual use of fire in Europe. Proceedings of the National Academy of Sciences [Internet] 108:5209–5214. Available from: http://dx.doi.org/10.1073/pnas.1018116108
    2. James SR. 1989. Hominid use of fire in the {Lower} and {Middle Pleistocene}: a review of the evidence. Current Anthropology 30:1–26.
    Synopsis: 
    Wil Roebroeks and Paola Villa claim the archaeological record doesn't provide evidence for systematic fire use in Europe before 400,000 years ago.
  • Mailbag: Fire starters

    Mon, 2010-05-17 13:51 -- John Hawks

    Regarding the use of fire, I’ve always been intrigued by how early Homo was able to continue its trek northward (ex. Dmanisi) without it. It would seem that a traveling hominid would frequently find itself out in the open (at night!!) without access to secure shelter while, at the same time, it was also experiencing more dramatic seasonal changes.

    I understand that the two-stone method of making fire isn’t particularly easy for an amateur. It would seem, however, that bashing rocks together to make tools on a dry savannah for a few thousand generations would have produced a clue as to how this worked. In fact, I would be surprised if they weren’t accidentally burning the neighbor-hood down on a regular basis. Maybe the initial production and control problem was learning how to put all these blazes out, not how to start them.

    There is evidence for fire in Swartkrans Member 3, which may be as old as 1.5 million years. The really good evidence from Gesher Benot Ya'aqov is sufficient to demonstrate control and habitual use of fires by 800,000 years ago. So it is not a safe assumption that the early occupation of temperate latitudes preceded fire use. If a 1.8-million-year-old site had evidence of fire, I think few of us would be surprised.

    The fire drill was repeatedly independently invented in different populations during the Late Pleistocene and Holocene -- it's one of the classic examples of diffusion and independent invention in cultural anthropology. So friction methods for fire making seem intuitive enough that humans come up with them again and again. To my mind these is easier and more consistent than the rock striking method, but who can say for sure?

    It does leave the question of why the systematic use of fire for landscape control is so late.

  • Mailbag: What is human?

    Tue, 2009-12-29 23:46 -- John Hawks

    Regarding Gesher Benot Ya'aqov:

    Am I missing something obvious? Your post, referring to the work at
    Gesher Benot Ya'aqov, refers to human activities 800,000 years ago.
    I'm just an interested layperson, but the rule of thumb I've always
    kept in my head was Homo sapiens sapiens beginning about 200kya, maybe
    double that for plain old Homo sapiens. What have I missed?

    I always use human as the adjective for Homo. So Neandertals are human, too -- and that gives a nice way not to have to fall back on "hominin." I suppose the right version for sapiens would be "sapient", although you don't see it nearly as often as "modern".

  • The fishy spaces of the Middle Pleistocene

    Fri, 2009-12-18 10:27 -- John Hawks

    In Science this week, Nira Alperson-Afil and colleagues report on recent excavations at Gesher Benot Ya'aqov, Israel. I saw some of this research presented at a conference, and I thought it was quite amazing to see the preservation of organic materials at this site. The Science paper is a good summary of the high points, presented in a very readable way.

    About the site:

    Gesher Benot Ya’aqov is located on the shores of the paleo–Lake Hula in the northern Jordan Valley in the Dead Sea Rift (7). The Early to Middle Pleistocene sediments document an oscillating freshwater lake and represent some 100,000 years of hominin occupation (Oxygen Isotope Stages 18–20) dating to 790,000 years ago (8, 9). Fourteen archaeological horizons indicate that Acheulian hominins repeatedly occupied the lake margins, where they skillfully produced stone tools, systematically butchered and exploited animals, gathered plant food, and controlled fire (7, 10–15).

    The current paper reports on a single occupation level, characterized by a hearth feature and associated plant, animal, and artifactual remains. Some interesting things:

    1. The plant remains:

    Although most taxa indicate wet habitats (e.g., lakes, lake margins, swamps, and near streams), the abundant fruit remains of woodland species such as olive, oak, and officinal storax (Styrax officinalis) imply human involvement, as their habitat was likely located some distance from the lake shore. Edible plants include oak acorns, prickly water lily (Euryale ferox) seeds, and water chestnut (Trapa natans) fruits; these were probably staple foods because of the nutritive value of their starchy nuts. Through roasting, the inedible shell of the nuts can easily be peeled and the tannin content of the acorns reduced. The fruits of the wild grapevine (Vitis sylvestris) and olive, and the leaves of the white beet (Beta vulgaris) and holy thistle (Silybum marianum), may also have been consumed.

    2. Crabs:

    The 17 crab specimens [minimum number of individuals (MNI) = 4 (22)], identified as the extant Potamon potamios, include pieces of the two asymmetric chelipeds, each with a distinctive form of the movable (upper) and fixed (lower) pincer....Of the seven pincers of the large cheliped present in Level 2, six occur around the hearth. These are the only crab remains in this area (fig. S4) (23).

    What's not to like about people eating crabs?

    3. Spatial patterning. There are two distinct areas of the horizon with anthropogenic activities -- the hearth and a second cluster of tools and stone waste flakes, I'm not very excited about the spatial distribution of activities. The story in the news is about how ancient humans knew how to "keep house" -- they're selling it as a major breakthrough in cognitive evolution.

    But the reason why we rarely have archaeological evidence about spatial patterning is that an archaeological horizon doesn't have very good temporal resolution. Here's an alternative scenario to account for the spatial pattern of remains in this horizon: One day, some people came, made tools and ate some fish. Three weeks later, some other people were in the same area, and they stayed for a few days, made a fire, did a bunch of other stuff.

    That's pretty much the spatial pattern that I would find if I went back home to Kansas and checked out campsites around the shore of the local reservoir. Few campsites are occupied for very long, and different people use them over time, sometimes with a fire, often not. Sure, we're cognitively advanced. I'm just not convinced that the spatial distribution of our campsite trash is very good evidence about it.

    Here's what the paper includes about the spatial patterning:

    The evidence from Gesher Benot Ya’aqov suggests that early Middle Pleistocene hominins carried out different activities at discrete locations. The designation of different areas for different activities indicates a formalized conceptualization of living space, often considered to reflect sophisticated cognition and thought to be unique to Homo sapiens (3). Modern use of space requires social organization and communication between group members, and is thought to involve kinship, gender, age, status, and skill (2).

    I think this is weak on two grounds -- first because the archaeology is poor evidence about the formal conception of living space, and second because it's not obvious that there's anything very unique about it.

    Why not unique? Any animal that can make a structure must have some capacity to pattern spatial activities -- if they don't, there's going to be poop everywhere. Conditioned on the fact that a human social group is sharing a single space, and group members are doing more than one activity, I don't see how you would ever expect to find a uniform scatter of evidence of these activities. There will always be some kind of spatial pattern, from the mere fact that two people can't occupy the same space at the same time.

    Remember that Gesher Benot Ya'aqov provides the earliest good evidence of human-controlled fire. It's no coincidence that "spatial patterning" should be found with a fire -- anything that people did anywhere other than by the fire is automatically evidence of a pattern.

    4. Fish. Now if there is one big reason why the spatial patterning is useful, it's the interpretation of the fish remains. It's not in the least bit surprising that there would be a lot of fish remains on an ancient lakeshore. But the remains are clustered into two distinct parts of the site, which happen to be the very two locations that humans were clearly using.

    In other words, once you accept that the archaeology gives you some evidence of where the people were within the site, you can test for association of the fauna and plant remains with the people. The crabs aren't all around the fire because of a failed attempt to stay warm at night; the people brought them there and ate them. The fish remains are clustered around the fire and flintknapping areas because people were eating them.

    Here's a good moral of the Gesher Benot Ya'aqov story: It's now past time to stop talking about whether "pre-modern" humans used aquatic resources. They did, sometimes intensively. I never understood why this argument about seafood and modern humans ever got any traction. We've known for twenty years that coastal Neandertals ate shellfish. We also have known from the numbers in caves near the coast that people never seem to have transported them very far inland. So there was a good reason why you didn't see more evidence of seafood; there just weren't that many sites very near the coast.

    So why was it news when a bunch of coastal African sites started producing evidence of shellfish consumption? Evidence that we already had for coastal Neandertals? I don't understand. Well, here we have people eating crabs and lots and lots of fish, 800,000 years ago. We can add the paper by Jose Joordens and colleagues earlier this year about Trinil (I reviewed it in "The shells of Trinil"), a million years ago or more.

    Another reason why Gesher Benot Ya'aqov is interesting: outside Africa, Middle Pleistocene sites (and Late Pleistocene sites, for that matter) have a fairly extreme bias toward caves and rock shelters. Caves can preserve evidence of within-site spatial patterns, and certainly offer some exceptional opportunities to track human activity over long periods of time. However, humans aren't very likely to have schlepped hundreds of fish from a lakeshore into some remote cave.

    UPDATE (2009-12-18) Thanks to a reader who pointed out a hanging omission; I corrected the text.

    References:

    Alperson-Afil N, Sharon G, Kislev M, Melamed Y, Zohar I, Ashkenazi S, Rabinovich R, Biton R, Werker E, Hartman G, Feibel C, Goren-Inbar N. 2009. Spatial Organization of Hominin Activities at Gesher Benot Ya’aqov, Israel. Science 326:1677-1680. doi:10.1126/science.1180695

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