DESCARGAR LAS OBRAS DEL AUTOR/DESCARREGAR LES OBRES DEL AUTOR

+SABER / +PENSAR / -TEORIA

miércoles, 29 de febrero de 2012

SOLUCIONES A LA CRISIS VII

Soluciones a la Crisis VII

Dicen que no podemos hacer nada, que los culpables de la crisis jamás podrán ser procesados, que el liberalismo económico impulsado por nuestros políticos en los ochenta va a seguir en boga y que el matrimonio poder con banca convivirá agazapado hasta que la muerte los separe. Pero para mejorar la democracia y evitar futuras crisis económicas como la actual sí existe una manera muy sencilla de dar pasos, un camino sin discursos intelectuales elitistas pero sí con acciones prácticas legales. Parece obvio que es imposible que todos podamos hablar a la vez con la gente supuestamente poderosa parta proponerles esto. Políticos, banqueros o grandes capitalistas son inaccesibles a todo el pueblo en bloque y con la idea que les diré no, no hace falta convencerles de mejorar la democracia con medidas justas para la mayoría. En democracia, y aunque no nos demos cuenta, el poder lo tenemos nosotros pero por desgracia no nos lo creemos. Por la anterior razón nos mostramos muy pasivos políticamente y no sabemos qué hacer. Si queremos mejorar la democracia basta con empezar con mociones en un ayuntamiento. Si por ejemplo creemos que la monarquía no es democrática nuestro ayuntamiento puede aprobar una moción a favor de la abolición de la monarquía sin pasarle nada, así de simple. Imagínese si ahora más y más ayuntamientos aprueban mociones para juzgar a cargos políticos y banqueros implicados en el endeudamiento español que todos estamos pagando con la crisis. O mejor aún, como hizo Islandia, negarse a pagar la deuda externa que ni usted ni yo contrajimos, fueron banqueros y gobernantes quienes lo hicieron. Si se llegase a una gran mayoría de ayuntamientos el Congreso debería secundar la voz de la mayoría. Para ello sólo hace falta ser una cosa, ser conscientes que podemos.

jueves, 23 de febrero de 2012

QUANT “QUI QUI” AMB LA CRISI

Quant es parla de la crisi hi ha tres qüestions que poc se’n parla i que esdevenen cabdals per a les nostres butxaques. Les tres preguntes es resumeixen en quant, qui, qui. Primera, quant devem? Segons el president Rajoy són uns 40.000 milions d’euros. Segona, qui va contractar aquest deute? Doncs el govern d’en ZP, Montilla i altres presidents conjuntament amb els seus socis econòmics. Tercera, qui s’està beneficiant del rèdit que els contribuents estem pagant amb més IVA, IRPF i demés? Doncs banques i financeres estrangeres moltes d’elles d’Alemanya. Davant tal injusta situació, que el poble no va decidir ni escollir, es podria enlairar la bandera de la nostra preuada democràcia i votar en contra de pagar tots aquests crèdits. Així mateix ho van fer els islandesos a l’inici de la crisi. Doncs per què aquí ningú es mou en aquest sentit? Doncs perquè abans que ningú comencés una iniciativa com aquesta el PP i el PSOE, demòcrates els dos, van pactar una reforma d’una cosa que deien era intocable, la Constitució, la nova que ara ens blinda el dret democràtic d’uns comicis en contra d’aquest injust pagament. Sàpiga el lector que per llei constitucional estem obligats a pagar aquest crèdit. En fi, els contribuents estem perdent cada dia més poder adquisitiu per tal que grans capitals cobrin dels nostres impostos, pèrdua de serveis socials i dret a la democràcia furtada. Ara no els estranyi que el PP apliqui mesures democràtiques, foren escollits per comicis, amb la seva reforma laboral, certes repressions per València o privant d’informació a membres d’ERC en el Congrés dels Diputats. Com deia en Sergi Mas fent de Montilla a Polònia, “visc a” la democràcia, però ara algú ens han prohibit gaudir-ne.

domingo, 19 de febrero de 2012

SOLUCIONES A LA CRISIS VI

Normalmente alguien sensato no hipoteca su vida por encima de sus posibilidades. Deber más de lo que uno no puede pagar significa arruinarse en su futuro, un pan para hoy pero hambre para mañana. La deuda pública contraída ha sido eso mismo, créditos para hoy pero deudas para el mañana. Lo perverso de nuestro anterior Gobierno fue que endeudaron al país a cuenta de nuestros bolsillos, es decir, que decidieron que sería usted quien se endeudaría sin pedirle apenas permiso. Ellos, los salientes, ostentan actualmente sueldos vitalicios, cargos importantes y seguros de vida que les cubren las espaldas con creces. El resto de contribuyentes pagan injustamente una hipoteca que no contrataron pero que bancos y entidades extranjeras ahora le cobran, ¿comprende ahora hacia donde van todos los recortes y aumento de impuestos? Entonces, ¿cuál fue el error? Pues que los Estados no pueden endeudarse por encima de sus posibilidades. La deuda española creció por encima de los ingresos y riqueza nacionales, por encima de su PIB. Alguien podría pensar que el error fue del pueblo, que no hubieran votado a los responsables de aquello, que aguanten ahora el chaparrón pero eso mismo argumentó el asesor de Adolf Hitler, Joseph Paul Goebbles, cuando los rusos masacraban a los alemanes en 1945. En fin, mejor regular en el futuro toda cadena de deudas entre estados y prestamistas que no dar la culpa a la democracia.

miércoles, 15 de febrero de 2012

WERE THERE RITUAL BURIALS IN THE SIMA DE LOS HUESOS OUTCROP? (Atapuerca Range, Burgos, Spain)

WERE THERE RITUAL BURIALS IN THE SIMA DE LOS HUESOS OUTCROP? (Atapuerca Range, Burgos, Spain)

David Rabadà i Vives
Museu de Geologia del Seminari de Barcelona
drabada@hotmail.com

ABSTRACT
The Sima de los Huesos site, Atapuerca, contains an important sample of fossilised human bones of Homo neanderthalensis. The nature of the Sima de los Huesos human remains was interpreted as human burials but geological, taphonomical and palaeocological evidences have given rise to a new interpretation. Ecological competition inside the cave site between Homo and predators’ accidents by falling into the cavity and old passages used as access to the chamber by human predators as felines and canines, explain this accumulation of human bones.
Key words: Taphonomy, human burials, neanderthal bones remains, Sima de los Huesos, Atapuerca, Pleistocene.


INTRODUCTION

The Pleistocene site of Sima de los Huesos at Atapuerca contains in only four cubic meters of sediments the highest concentration of primitive Neanderthals around the world. More than thirty-two individual remains were found in that rock volume. This condensation of hominid fossils was explained as human burials by primitive Neanderthals who threw their dead relatives to the cave site as a symbolical act (Arsuaga & Martínez, 1998; Arsuaga, 1999; Carbonell et al., 2003). If this hypothesis is true we would be at the first human funeral rite. This paper attempts to deconstruct this interpretation reviewing three aspects of the site, its taphonomy, its paleoecology and its geology. At the end we will join them to discuss a new interpretation.

The Sima de los Huesos fossiliferous site was deposited between 205,000 and 325,000 years ago (Parés et al., 2000) but other investigations talk about 400,000 and 500,000 years ago (Bischoff et al., 2003, Bermúdez de Castro et al ., 2003). This fossil site is located at the end of a dark gallery of 400 meters where it opens a chasm of 13 meters high (Arsuaga et al., 1993, Arsuaga et al., 1997). Inside the cave only predators have been identified including a group of hominids. These were attributed initially to archaic Homo sapiens (Arsuaga et al., 1993) but later they were identified as Homo heidelbergensis (Perez et al., 1999; Arsuaga & Martínez, 1999). In fact, Homo heidelbergensis is an early variety of Homo neanderthalensis. The high variability found in the Sima de los Huesos site (Arsuaga & Martínez, 1999) indicates that Neanderthals contain the old heidelbergensis without any taxonomical problem. At the moment these authors keep the name Homo heidelbergensis instead of Neanderthal in their publications for practical reasons but not taxonomical (Arsuaga & Martínez, 1999).

The Homo neanderthalensis concentration in the Sima de los Huesos site is associated with bone remains of other carnivores, especially bears and foxes (Arsuaga & Martínez, 1998). The absence of herbivore remains was considered a difficult question to resolve (Arsuaga & Martínez, 1998; Arsuaga, 1999) but later we will see an easy interpretation.


TAPHONOMICAL DATA

There are two important taphonomical processes inside caves, the first involves presence of vertebrate fossils in their sediments and the second generates skeletal concentrations. On the other hand karst cavities don’t usually involve rapid burial mechanisms (Smith, 1975, Atkinson & Smith, 1976; Sorriaux, 1982) but caves minimize weather action which breaks and disperses skeletal remains (Hill, 1979; Haynes, 1980). Therefore the discussion about the Sima de los Huesos remains has to be focused on concentration mechanisms of bones. There are many causes which accumulate skeletal remains in caves and caverns (Weigelt, 1927; Brain, 1958, Behrensmeyer, 1978; Brain, 1981; Andrews, 1990, Domínguez-Rodrigo, 1994). The presence of vertebrate fossils in caves can be caused by rodents or predators carrying the bones, hibernation, reproduction, natural traps, mud flows, debris flows, sudden death by karst collapse, flooding inside cavity or illness of a group of organisms (Weigelt, 1927; Brain, 1958, Vrba, 1976; Maguire, 1976; Behrensmeyer, 1978; Brain, 1981; Andrews, 1990, Domínguez-Rodrigo, 1994). All these mechanisms can explain the presence of skeletal remains inside caves but not necessarily its accumulation. There are three contexts which can produce the concentration of bones . First context is continuous supply of corpses for a short period of time (Andrews, 1990), second is eventual supplies for a long time (Andrews,1990) and third a low sedimentation rate (Rabada, 1990). Combinations of these three contexts accumulate and concentrate bones inside caves. If we want to know what happened in the Sima de los Huesos site we have to consider the characteristics of their human remains. The total number of skeletal parts and the inferred number of human individuals show us how partial is the Sima de los Huesos fossil record. The thirty-two Neanderthals were identified from 1300 skeletal parts but the total number of skeletal parts of thirty-two individuals should be much higher. This fact presupposes two things, the first more than sixty percent of the original remains is missing, especially skulls and vertebrae (Andrews & Fernández-Jalvo, 1997, Fernández-Jalvo & Andrews, 2001), and the second this association fossil shows a dispersion of large bones. If Neanderthal remains was carried as a human burial rite we have to suppose that these were whole bodies and not parts of them. Therefore we should find a dispersion and dismantling lower than this sixty percent of missing remains. On the other hand there are a lot of cranial remains with abrasions and fractures. Some authors have suggested that these injuries were caused by impacts of stones which Neanderthals threw to each other (Arsuaga, 1999), but it seems more logical that these scars were produced when falling into the Sima de los Huesos pit because there are no signs of cranial healing. Weigelt described bone trauma in fallen animals in potholes (Weigelt, 1927) as Atapuerca fossil association seems to indicate. But there is a problem with this interpretation. When some animals fall in a place inaccessible to predators they tend to generate fossil associations without bite marks. The Sima de los Huesos human remains show a lot of bite marks in the majority of bones (Andrews & Fernández-Jalvo, 1997, Fernández-Jalvo & Andrews, 2001). The abundance of bears found with Neanderthals might suggest that these predators perpetrated these bite marks (Rabada, 2001) but bears chew bones producing a characteristic pattern with rounded epiphyses (Weigelt, 1927, Domínguez-Rodrigo, 1994) which is not found on the association of the Sima de los Huesos human fossils but is found in bears’ skeletons (Andrews & Fernández-Jalvo, 1997; Fernández-Jalvo & Andrews, 2001). On the other hand a very close relative of the extinguished bear cave, Ursus arctos, the current European bears, eats its preys outside caves without moving them to the cavities. In fact, they used to hibernate inside caves where they sometimes died and ate themselves producing the rounded epiphyses. This process explains the accumulation of bear bones inside cavities (Weigelt, 1927, Domínguez-Rodrigo, 1994) but not the concentration of human remains. Therefore bears didn’t produce the human bone accumulation in the Sima de los Huesos site and we need to study the Atapuerca paleoecological data for answering who caused it.


PALAEOECOLOGICAL DATA

The Sima de los Huesos fossil association contains only predators but not herbivores. The main Atapuerca predators with 50 percent of individuals estimated are bears, followed by humans with 11 percent and foxes with 8 percent. The rest, felines, wolves and weasels are a minority (Andrews & Fernández-Jalvo, 1997, Fernández-Jalvo & Andrews, 2001). Therefore the Sima de los Huesos fossil association has a general absence of herbivores and a clear predominance of bears, hominids and foxes. The absence of herbivores in the old Atapuerca ecosystem was impossible. Something avoided his presence inside the cave. We will explain it later.

Another important aspect is the close relation between bears and humans. These animals and Neanderthals used caves as a temporary shelter for millennia, bears as a hibernation place and humans as a campsite. When Neanderthals stayed in cavities they carried preys inside for consumption, producing a lot of cut marks on the bones and collections of stone tools. This fact doesn’t happen in the Sima de los Huesos site (Andrews & Fernández-Jalvo, 1997, Fernández-Jalvo & Andrews, 2001) although one handaxe was found (Carbonell et al., 2003). Therefore the common situation between bears and hominids was their specialized omnivorous and carnivorous strategies as predators, their competing for similar food resources and caves as a resting place. The Sima de los Huesos site represented an area of ecological competition between these two species. Neanderthals, being nomadic, periodically revised the cave for various uses while bears hibernated in the cavity every year with high risk of falling inside the Sima de los Huesos pothole. It has been observed chasms trap other predators when they come to inspect a cave for eating falling corpses (White et al. 1984). The same could have happened if Neanderthals tried to inspect the Sima de los Huesos. We have to remember that this pit was at the end of a long and dark gallery. In other words, bears and hominids shared the same accident risk under the same competition for habitat and this situation could caused the accumulation of bears and human corpses in the pit (Rabada, 2001). The only handaxe found in the Sima de los Huesos (Carbonell et al., 2003) could be a tool brought or thrown by a Neanderthal. But this mechanism did not introduce the majority of corpses inside the site. The distribution of human ages shows new information. Fossils can reflect the mortality rate of the original population. Infant mortality rate in current hunter-gatherer is very high followed by old people (Blurton Jones et al., 1992, Howell, 1979) which also occurred in neanderthal populations (Trinkaus, 1995). If the Sima de los Huesos site was generated as intentional burial, it should contain a high number of children and elders but according to published data, 52 percent of Neanderthal remains were adolescents and young adults. On the other hand 60 percent of them were less than 19 years old and 90 percent older than 27 (Bermúdez de Castro & Nicolas, 1997; Arsuaga, 1999). Therefore Neanderthals between 0 to 11 years old and over 27 were underrepresented in the Sima de los Huesos site. This predominance of middle age and partial absence of children and old people doesn’t indicate a mortality rate but something very different, an accident risk rate (Rabada, 2001). Teens and young adults tend to be fearless and they go away from households more than babies and old people. This fact involves high risk of contingencies for young humans. On the other hand bears died in that dark abyss when hibernating and falling inside the hole. Perhaps the same accident could have happened to young Neanderthals but the low skeletal fractures rate observed invalidates this hypothesis (Andrews & Fernández-Jalvo, 1997, Fernández-Jalvo & Andrews, 2001). Thus, the main input mechanism of human remains was another. Other authors explained this human remains accumulation as a sudden death for all the Sima de los Huesos Neanderthals (Bocquet-Appel & Arsuaga, 1999) but this reasoning involves a paradox and a new question, did humans die suddenly in the pothole while many bears, foxes and lions didn’t ? In fact the percentage of bones shows us a new and easier interpretation. There is a clear predominance of cranial, arms and legs remains in the Sima de los Huesos site. Teeth, jaws and limb bones as femurs, humerus and tibias are more frequent than ribs, vertebrae and metacarpials, which are very scarce. All these percentages involve a partial transport of bones (Andrews & Fernández-Jalvo, 1997, Fernández-Jalvo & Andrews, 2001). Lions and leopards produce this kind of bones accumulation because limbs contain a large quantity of meat for feeding (Bailey, 1993). Moreover fifty percent of the human remains are affected by bite marks, especially femora at 96 percent. These incisions were caused by wolves, foxes and some big felines that had had access to the remains before (Andrews & Fernández-Jalvo, 1997, Fernández-Jalvo & Andrews, 2001). Therefore a big feline brought the human remains inside the cave site for feeding. But if felines were the first to eat the human meat, how are they so scarce in Sima de los Huesos shaft? And the most important thing, how did felines and canines come in the pit and go out from it?


GEOLOGICAL DATA

Some predator transported the human remains of the Sima de los Huesos site as prey. This fact raises two questions. First, how did the concentration of bones happen in the cavity? And second, how did predators come in and go out from this pit?

The concentration of skeletal remains in caves may be due to continuous supply of corpses for a short period of time, eventual contribution for a long time or low sedimentation rate.
The first, continuous supply of dead bodies is common in colonial animals. An example of this are bats (Andrews, 1990) but the hunter-gatherers current population density is very low (Blurton Jones et al., 1992, Howell, 1979) as well as social predators as wolves and felines (Vicente et al., 1999). Predators need large areas for survival which involves a very low population density. On the other hand, the absence of cut marks in Sima de los Huesos bones indicates that there was not a substantial hominid colony inside the pit. Therefore, the concentration of corpses in the cave was given by another mechanism.

The second reason for the concentration of bones, slight remains contribution for long periods, has many examples like feeding regurgitation by owls and eagles (Andrews, 1990), feeding troughs (Brain, 1958), falls into trap chambers (Morris, 1974; White et al. 1984; Andrews, 1990), troughs (Vrba, 1976) and hibernating places (Kurt, 1958, Kurt, 1976). Falls inside the pit and feeding troughs were the most probable mechanisms for human remains in the Sima de los Huesos outcrop. The cave morphology with a chasm at the end of a dark gallery and the bite marks in bones indicate these interpretations. On the other hand, the third context, low sedimentation rates, allowed the observed concentration of bones. Cave clays belong to limestone non-soluble fraction. Cavities are due to calcium carbonate dissolution. High percentage of limestone is soluble in water but a small part of clays are not. Therefore, clay generation during a cave formation is scarce. This context involves the observed low sedimentation rate inside cavities. The idea is simple, many bones inside a low clay percentage produces a level of bones condensation. This new explanation is contingent with two more aspects from Atapuerca site. The first is the observed abrasion in 24 percent of human remains (Andrews & Fernández-Jalvo, 1997, Fernández-Jalvo & Andrews, 2001). The low sedimentation production allowed a high bone transport rate inside karst, which involved the observed bone fragmentation and abrasion. The second aspect was the different sedimentation ages found in the outcrop. According to a first sample this age was between 325,000 to 205,000 years old (Parés et al., 2000) but another measure proposed an age between 400,000 to 500,000 years old (Bischoff et al., 2003; Bermudez de Castro et al. 2003). Condensation levels mix fossils from different ages as in the Sima de los Huesos could happen. Perhaps this data dispersion was due to a low sedimentation rate in the Sima de los Huesos pit.

The next problem to solve is how big felines came in and out of the pit. They probably killed young and inexpert Neanderthals while canines came later for feeding on human flesh (Andrews & Fernández-Jalvo, 1997, Fernández-Jalvo & Andrews, 2001). Geological data could explain how all these predators and scavengers came inside and escaped from the chasm. Water does not dilute limestone in a karst system entering and exiting through the same place. The cavities formation produced accesses higher than others. Water flows inside by first entrances and escapes by lower. Collapse and debris flows happen during this process burying old entrances and exits. Therefore there was another lower access in the Sima de los Huesos pit. Felines and canines came in and went out of the cavity through this old buried cave by slumps. Two entries were described in the Sima de los Huesos site (Arsuaga et al., 1997) but they were discarded by those authors. They believed that these entries were sealed 400,000 years ago. Nowadays there is no age data about it and the slump age is not studied. We can suppose that those cavities were the access at that time, explaining entrances and exits of felines to the pit. This interpretation explains the absence of herbivores in the Sima de los Huesos site. If those big felines haunted herbivores they would kill them in the plains around the current Atapuerca range. Herbivores don’t stay a long time inside mountains and forests because they prefer open fields to avoid predators and inside caves there is not grass for them. On the other hand, large predators as lions and leopards move corpses only a few hundred meters (Schaller, 1972; Kitchner, 1991; Bailey, 1993). All these reasons explain the absence of herbivores in the Sima de los Huesos fossil association. This context was different for Neanderthals because they frequently lived near the range caves and they were potential victims for large predators near these cavities. This interpretation also explains the greater abundance of bears at the top of the fossil formation (Andrews & Fernández-Jalvo, 1997, Fernández-Jalvo & Andrews, 2001). When the pit was closed at its base, the only mechanism of bear bone contribution was accidentally falling by hibernation. Similarly, the greater abundance of hominids in the bottom of fossil formation could occur while the lower access remained opened with predators bringing corpses inside the cave. All these bones were reworked by water flows. The abrasions over 24 percent of the remains indicate an intense reworking of fossil association after initial burial (Andrews & Fernández-Jalvo, 1997). These authors interpret the Sima de los Huesos remains as a mixture of different fossil associations (Fernández-Jalvo & Andrews, 2001) and probably with different ages (Rabadà, 2007). The water passage along caves during heavy rainfall events would involve the dispersion, mixing and abrasion observed on these skeletal remains.


CONCLUSIONS

A monolithic interpretation does not explain natural processes because these are consequences of a network of causes. The Sima de los Huesos fossil association was considered only as a human burial site by other authors but according to geological, taphonomical and paleoecological data this outcrop was originated by different taphonomical mechanisms. Competition between Neanderthals and other predators for the cavity, accidental death by falling into the pit and a feeding trough for felines and canines while the cave had other entrances blocked nowadays explain this fossil association. The bears fell by accident or died while hibernating there. Neanderthals could suffer the same fate but they were more probably victims of predation by large felines that carried the corpses inside. Foxes and other scavengers came later for feeding. The water flows in the karst during heavy rainfalls produced dispersion, mixing and abrasion in all these skeletal remains. At the end a low sedimentation rate produced the observed fossils concentration.



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Rabadà, D. 2007. La asociación fósil de la Sima de los Huesos: resultado de diversos procesos tafonómicos no antrópicos (Sierra de Atapuerca, Burgos, España). Batalleria. Museo Geológico del Seminario Conciliar de Barcelona, 13, 69-74.
Schaller, G. 1972. The Serengeti Lion. Chicago: University of Chicago Press.
Smith, D.I. 1975. The erosion of limestones on Mendip. In: D.I. Smith & D.P. Drew (eds) Limestones and Caves of the Mendip Hills. 135-170. British Cave Research Association, David & Charles.
Sorriaux, P. 1982. Contribute a l'etude de la sedimentation en milieu karstique: le systeme de niaux-lombrives-sabart. Pyrenees Ariegeoises. Univ. Paul Sabatier. Toulouse. 255pp.
Trinkaus, E. 1995. Neanderthal mortality patterns. Journal of Archaeological Science, 22, 121-142.
Vicente, J.L., Rodríguez, M. & Palacios, J. 1999. Relaciones entre lobos y ciervos en la sierra de la Culebra. Quercus, 157, 10-15.
Vrba, E. 1976. The significance of bovid remains as indicators of environment and predation patterns. In: Fossils in the Making (Butzer and Freeman eds.). The University Chicago Press.
Weigelt, J. 1927. Recent Vertebrate Carcasses and their Paleobiological Implications. The University Chicago Press. 188 pp.
White, J.A., McDonald, H.G., Anderson, E. & Soiset, J.M. 1984. Lava blisters as carnivore traps. Special Publications Carnegie Museum Naural History, 8, 241-256.

martes, 14 de febrero de 2012

SOLUCIONES A LA CRISIS V

Durante las últimas décadas parece que el nivel adquisitivo de la clase trabajadora ha caído estrepitosamente a cambio de ampliar la riqueza de unos pocos directivos. En abril del 2009 Pierre-Antoine Delhommais escribía para Le Monde que la diferencia media entre el salario de un director general y el de un trabajador en USA era de 1 a 40 en 1980. Esta distancia pasó de 1 a 411 en 2005. Añadamos que entre 1998 y 2006 los sueldos de casi el 90 % de los franceses quedaron estancados mientras que el 10 % restante de clase rica aumentó un 9 % y el 0,01% de los más ricos se engrosó un 43 %. Tengo la impresión que lo mismo nos ha sucedido por la península ¿Y cuál ha sido la causa? Pues la búsqueda de los máximos beneficios por parte de los grandes capitales y un erróneo liberalismo económico permitido por los gobiernos. Cabe averiguar de donde surge tal ideología y la respuesta es de las escuelas de altos negocios occidentales. Parece obvio que los futuros yuppies, brokers o gestores de finanzas no deberían ser entrenados para convertirse en ávidos directivos de ganancias sin ningún tipo de remordimientos, que estos golden boys, smart o quick no deberían desear brillar por sólo los beneficiosos engendrados sino por construir algo que a largo plazo genere lugares de trabajo y productos útiles que ofrecer a la sociedad. Parece como si estos aprendices llegaran a pensar que una empresa es una ficha de ajedrez a mover a su antojo, que el único idioma a utilizar es el globish, o inglés global de los negocios, y que enriquecerse con el mínimo esfuerzo resulta algo totalmente loable. ¿Que tal entonces, y por ley, un poco de comercio justo obligatorio, teoría de banca de microcréditos y un juramento hipocrático de buena conducta al crear y gestionar productos financieros? ¿Qué tal unas leyes que volvieran a regular las especulaciones y los productos financieros? Por ahora sólo se prioriza que las grandes empresas aumenten sus ingresos con publicidad y márqueting agresivos provocando la compra de bienes innecesarios y la reducción de gastos con más despidos.

lunes, 13 de febrero de 2012

Taphonomy, human burials, neanderthal bones remains, Sima de los Huesos, Atapuerca, Pleistocene.

WERE THERE RITUAL BURIALS IN THE SIMA DE LOS HUESOS OUTCROP? (Atapuerca Range, Burgos, Spain) (modified 13/11/2012 to Palevol, Elsevier ed.) David Rabadà i Vives Museu de Geologia del Seminari de Barcelona ABSTRACT The Sima de los Huesos site, Atapuerca, contains an important sample of fossilised human bones of Homo heidelbergensis. The nature of the Sima de los Huesos human remains was interpreted as human burials but geological, taphonomical and paleoecological evidences have given rise to a new interpretation. According to this new interpretation this outcrop was originated by different taphonomical mechanisms. Competition between Homo and other predators for the cavity, accidental death by falling into the pit and a feeding trough for felines and canines while the cave had other entrances blocked nowadays, explain this fossil association. The bears fell by accident or died while hibernating there. Homo could suffer the same fate but they were more probably victim of large felines or others that carried the corpses inside or around the pit. Foxes and other scavengers came later for feeding. The water flows in the karst during heavy rainfalls produced dispersion, mixing and abrasion in all these skeletal remains. During all these processes a low sedimentation rate produced the observed fossils concentration. Key words: Taphonomy, human burials, Homo heidelbergensis, Sima de los Huesos, Atapuerca, Pleistocene. INTRODUCTION The Pleistocene site of Sima de los Huesos at Atapuerca contains the highest concentration of primitive Neanderthals or Homo heidelbergensis around the world. In fact, the most appropriate name for this lineage is Homo neanderthalensis, although it is also possible to admit, only for practical reasons, the succession of two chronospecies, Homo heidelbergensis and Homo neanderthalensis (Bermúdez de Castro et al., 2004). In Sima de los Huesos site more than thirty-two individual remains were found in only four cubic meters of sediments. This condensation of hominid fossils was explained as human burials by this primitive Homo who threw their dead relatives to the cave site as a symbolical act (Arsuaga & Martínez, 1999; Arsuaga, 1999; Carbonell et al., 2003; Carbonell & Mosquera, 2006). If this hypothesis is true we would be at the first human funeral rite. This paper attempts to deconstruct this interpretation reviewing three aspects of the site, its taphonomy, its paleoecology and its geology. At the end we will join them to discuss a new interpretation. The Sima de los Huesos fossiliferous site was originated between 205,000 and 325,000 years ago (Parés et al., 2000) but other investigations talk about 400,000 and 500,000 years ago (Bischoff et al., 2003; Bermúdez de Castro et al., 2003). This fossil site is located at the end of a dark gallery of 400 meters where it opens a chasm of 13 meters high as cave profiles have been shown by different authors (Arsuaga et al., 1993; Arsuaga et al., 1997; García & Arsuaga, 2011). Inside the cave only predators have been identified including a group of hominids. These were attributed initially to archaic Homo sapiens (Arsuaga et al., 1993; Bermúdez de Castro et al., 1997) but later they were identified as Homo heidelbergensis (Pérez et al., 1999). The high variability found in the Sima de los Huesos site indicates that Neanderthals contain the old heidelbergensis without any taxonomical problem (Arsuaga & Martínez, 1999). At the moment these authors keep the name Homo heidelbergensis instead of Neanderthal in their publications for practical reasons but not taxonomical (Arsuaga & Martínez, 1999; Bermúdez de Castro et al., 2004). The primitive Homo neanderthalensis concentration in the Sima de los Huesos site is associated with bone remains of other carnivores, especially bears and foxes (Arsuaga & Martínez, 1999). The absence of herbivore remains was considered a difficult question to resolve but related with human burials (Arsuaga, 1999), but later we will propose a possible interpretation without relation with them. The problem of Sima de los Huesos site is the absence of similar outcrops with equivalent geology and fossil assemblage. Therefore it is very difficult to distinguish natural bone accumulations from human burials. The main findings about treatment of the dead during the Pleistocene age come from repeated studies of cut marks, scraping marks, bone breakage of human bones regarded as purposive mortuary practices (Ullrich, 1999) but all these factors are not observed at the Sima de los Huesos site. The occurrence and situation of this outcrop has very few known parallels for the Palaeolithic record. The only remotely analogous finding might be the Cueva del Angel, near Córdoba in Andalusia (Barroso et al., 2011), where a very deep cleft has been identified with animal food refuse, hand axes and human remains inside. At any rate, Sima de los Huesos site only contains human and carnivores remains while Cueva del Angel represents something very different. The assemblage of large herbivores in the Cueva del Angel corresponds to an accumulation of anthropic origin during a long period from the end of the Middle Pleistocene to the beginning of the Upper Pleistocene where humans brought large quantities of meat into the cave from essentially horses and bovids in the form of dismembered and cut (Barroso et al., 2011). Cueva del Angel fossil assemblage shows an appreciable number of cutmarks and striations (9% of the material) related to defleshing, filleting and disarticulation, and high proportion of burnt elements (88% of the material) while this characteristics doesn’t exits at Sima de los Huesos fossil assemblage. Therefore this outcrop hasn’t direct taphonomical relation with Sima de los Huesos outcrop. Cueva del Angel was a site of intense and continuous occupation for butchering and cooking of animal meat resources predated and transported into the cave by humans and Sima de los Huesos wasn’t it. TAPHONOMIC DATA If we want to understand fossil assemblages inside caves there are two important taphonomical processes, the first involves only presence of vertebrate fossils in their sediments and the second generates skeletal concentrations. The Sima de los Huesos outcrop shows a high quantity of bone remains with excellent bone preservation. Therefore, the discussion about this site has to be focused on concentration mechanisms of bones. There are many causes which accumulate skeletal remains in caves and caverns (Weigelt, 1989; Brain, 1958; Behrensmeyer, 1978; Brain, 1981; Andrews, 1990; Domínguez-Rodrigo, 1994). The presence of vertebrate fossils in caves can be caused by rodents or predators carrying the bones, hibernation, reproduction, natural traps, mud flows, debris flows, sudden death by karst collapse, flooding inside cavity or illness of a group of organisms. All these mechanisms have explained the presence of skeletal remains inside caves, but not necessarily its concentration. There are three contexts which can produce this fact. First context is continuous supply of corpses for a short period of time (Andrews, 1990), second is eventual supplies for a long time (Andrews, 1990) and third a low sedimentation rate (Rabadà, 1990). Combinations of these three contexts accumulate and concentrate bones inside caves. If we want to know what happened in the Sima de los Huesos site we have to consider the characteristics of their human remains. At the moment human remains are mixed with others mammals bones and without anatomical connections (Arsuaga et al., 1993) and complete human skeletons were computed from tooth, jaws and limbs (Arsuaga et al., 1997). For instance, the human remains from Sima de los Huesos, but never entire bodies, have allowed to reconstruct 27 complete long bones to estimate for each bone an average body stature about 163.6 cm for the Sima de los Huesos hominids (Carretero et al., 2012), therefore there aren’t complete human skeletons with anatomical connections in the Sima de los Huesos outcrop until today. The total number of skeletal parts and the inferred number of human individuals show us how partial is the Sima de los Huesos fossil record. The thirty-two individuals were identified from only 1300 skeletal parts but, the total number of skeletal parts of thirty-two heidelbergensis should be much higher, more than 3.000. This fact presupposes two things, the first more than sixty percent of the original remains is missing, especially skulls, phalanges and vertebrae (Andrews & Fernández-Jalvo, 1997; Fernández-Jalvo & Andrews, 2001), and the second this association fossil shows a dispersion of large bones. If human remains were carried as a sepulchral rite we have to suppose that these were whole bodies and not parts of them. Therefore, we should find dispersion and dismantling lower than this sixty percent of missing remains. On the other hand, there are many cranial remains with abrasions and fractures. Some authors have suggested that these injuries were caused by impacts of stones when they were fighting or playing to each other (Arsuaga, 1999), but it seems more logical that these scars were produced when falling into the Sima de los Huesos pit or when water currents reworked the human remains because there are no signs of cranial healing. Weigelt (1989) described bone trauma in fallen animals in potholes as Atapuerca fossil association seems to indicate. But there is a problem with this interpretation. When some animals fall in a place inaccessible to predators they tend to generate fossil associations without bite marks. The Sima de los Huesos human remains show many bite marks on the majority of bones (Andrews & Fernández-Jalvo, 1997; Fernández-Jalvo & Andrews, 2001). The abundance of bears found with humans might suggest that these predators perpetrated these bite marks (Rabadà, 2001), but bears chew bones producing a characteristic pattern with rounded epiphyses (Weigelt, 1989; Domínguez-Rodrigo, 1994) which is not found on the association of the Sima de los Huesos human fossils but is found in bears’ skeletons (Andrews & Fernández-Jalvo, 1997; Fernández-Jalvo & Andrews, 2001). On the other hand, a very close relative of the extinguished bear cave, the current European bears, eats its preys outside caves without moving them to the cavities. In fact, they used to hibernate inside caves where they sometimes died and ate themselves producing the rounded epiphyses. This process explains the accumulation of bear bones inside cavities (Haynes, 1983; Weigelt, 1989; Domínguez-Rodrigo, 1994), but not the concentration of human remains. Moreover, there are bite marks from bears on bears bones but not over human bones (Fernández-Jalvo, 2003) and therefore bears didn’t produce the human bone accumulation in the Sima de los Huesos site but they ate themselves inside the cave during hibernation. If we want to understand human bones concentration at Sima de los Huesos site we need to study the Atapuerca paleoecological data for answering who caused this human remains accumulation. PALAEOECOLOGICAL DATA The Sima de los Huesos fossil association contains only predators, but not herbivores. The main Atapuerca predators with 50 percent of individuals estimated are bears, followed by humans with 11 percent and foxes with 8 percent. The rest, felines, wolves and weasels are a minority (Andrews & Fernández-Jalvo, 1997; Fernández-Jalvo & Andrews, 2001). Therefore, the Sima de los Huesos fossil association has a general absence of herbivores and a clear predominance of bears, hominids and foxes. The absence of herbivores in the old Atapuerca ecosystem was impossible. Something avoided his presence inside the cave. We will try to explain it later. Another important aspect is the close relation between bears and humans. These animals and Homo heidelbergensis or neanderthalensis used caves as a temporary shelter for millennia, bears as a hibernation place and humans as a campsite. When humans stayed in cavities, they carried preys inside for consumption, producing many cut marks on the bones and collections of stone tools as Cueva del Angel (Barroso et al., 2011). This fact doesn’t happen in the Sima de los Huesos site (Andrews & Fernández-Jalvo, 1997; Fernández-Jalvo & Andrews, 2001), although one hand axe was found (Carbonell et al., 2003; Carbonell & Mosquera, 2006) which belongs to a reworked element as we will describe later. Therefore, the common situation between bears and hominids was their specialized omnivorous and carnivorous strategies as predators, their competing for similar food resources and caves as a resting place. The Atapuerca range represented an area of ecological competition between these two species. Homo, being nomadic, periodically revised the cave for various uses while bears hibernated in the cavity every year with high risk of falling inside the Sima de los Huesos pothole. It has been observed chasms trap other predators when they come to inspect a cave for eating falling corpses (White et al., 1984). The same could have happened if Homo tried to inspect the Sima de los Huesos. We have to remember that this pit is located at the end of a long and dark gallery (Arsuaga et al., 1993; Arsuaga et al., 1997; García & Arsuaga, 2011). In other words, bears and hominids shared the same accident risk under the same competition for habitat and this situation could caused the accumulation of bears and human corpses in the pit (Rabadà, 2001). The only hand axe found in the Sima de los Huesos could be a tool brought by a Homo near the cave and reworked with the rest of skeletal remains. But, this mechanism did not introduce the majority of corpses inside the site. The distribution of human ages shows new information. Fossils can reflect the mortality rate of the original population. Infant mortality rate in current hunter-gatherer is very high followed by old people (Jones et al., 1992; Howell, 1979) which also occurred in Neanderthal populations (Trinkaus, 1995). If the Sima de los Huesos site was generated as intentional burial, it should contain a high number of children and elders, but according to published data, 52 percent of human remains were adolescents and young adults. On the other hand, 60 percent of them were less than 19 years old and 90 percent less than 27 (Bermúdez de Castro & Nicolas, 1997; Arsuaga, 1999). There are only the testimonial presence of one individual under the age of 10 years in the Sima de los Huesos site (Bermúdez de Castro et al., 2004). The fragile and delicate remains of infants and children are more severely affected by the action of biostratinomic and fossildiagenetic agents than bones from adolescents and adults. Moreover caves minimize weather action (Hill, 1979; Haynes, 1980). Therefore the fossil preservation in Sima de los Huesos site was excellent and the distribution of human ages should be equivalent with the original corpses number. Therefore, humans between 0 to 11 years old and over 27 were underrepresented in the Sima de los Huesos site. This predominance of middle age and scarcity of infants and old individuals doesn’t indicate a mortality rate, but something very different, an accident risk rate (Rabadà, 2001). Teens and young adults tend to be fearless and they go away from households more than babies and old people. This fact involves high risk of contingencies for young humans. On the other hand, bears died in that dark abyss when hibernating and falling inside the hole. Perhaps the same accident could have happened to young humans, but the low skeletal fractures rate observed invalidates this hypothesis (Andrews & Fernández-Jalvo, 1997; Fernández-Jalvo & Andrews, 2001).## Thus, the main input mechanism of human remains was another. For instance, other authors discarded the hypothesis that the site was a primitive cemetery but they suggested instead that the mortality distribution could be the result of a catastrophe as a sudden death for all the Sima de los Huesos human individuals, although they did not specify the origin of the accumulation and didn’t explain this human remains concentration (Bocquet-Appel & Arsuaga, 1999). The last reasoning involves a paradox and a new question, did humans die suddenly in the pothole while many bears, foxes and others didn’t it? In fact, the percentage of bones shows us a new and easier interpretation. There is a clear predominance of arms and legs remains in the Sima de los Huesos site. The fossil assemblage shows high amount of humeri and tibiae which can indicate accumulation by scavengers. Teeth, jaws and limb bones as femurs, humeri and tibiae are more frequent than ribs, vertebrae and metacarpials, which are very scarce. All these percentages involve a partial transport of bones at Sima de los Huesos site (Andrews & Fernández-Jalvo, 1997, Fernández-Jalvo & Andrews, 2001). The fact that some 60 % of the bodies’ bones are missing, particularly vertebra, cranial elements and phalanges without presence of coprolits (Andrews & Fernández-Jalvo, 1997; Fernández-Jalvo & Andrews, 2001) seems to support that the Sima de Los Huesos fossil human accumulation had little to do with ritual burials that involved carrying of the corpses. Human phalanges remains are scarce, which seems to buttress some selective transport. Perhaps lions, leopards and hyenas produced the first bone human accumulation because limbs contain a large quantity of meat for feeding while ribs, vertebrae and metacarpials don’t (Bailey, 1993). Metacarpials contains relatively little nutritional value, carnivores rarely fragment them. Phalanges are nearly absent at many modern hyena dens, and fossil carnivore accumulations often exhibit low numbers of phalanges (Hutson, 2008). Moreover fifty percent of the human remains at Sima de los Huesos are affected by bite marks, especially femora at 96 percent and, in general, on limb bones. The Sima de los Huesos site contains a bone-bearing breccia with clayish matrix mainly composed of Ursus deningeri (MNI: 176), Vulpes vulpes (MNI: 21), Canis sp. (MNI: 1), Panthera leo cf. fossilis (MNI: 3), Panthera sp. (jaguar-size; MNI: 1), Felis silvestris (MNI: 1), Lynx pardinus spelaeus (MNI: 2) Martes sp. (MNI: 1), Mustela nivalis (MNI: 2), Mustela putorius (MNI: 3) and Meles meles (MNI: 1) (García, 2003). According with this last list, large carnivore as felines could be the first producers of Sima de los Huesos human remains accumulation. Opportunistic predators as lion or leopard used to concentrate bone preys. Since Pleistocene hominid hunter-gatherers are regarded as apex carnivores in a competitive carnivore guild (Eaton, 1994). The total of some 32 individuals at Sima de los Huesos site as preys would not be out of character with a comparatively low rate of predation on ancient humans by medium or large carnivores at the site. Therefore large carnivores could hunt human individuals during Pleistocene. In this case, and if indeed the human remains were carried near the cave by predators, which carnivore species was involved? Spotted hyenas, and probably their Pleistocene ancestors, Crocuta spelaea, are known to dig up buried humans in Ethiopia, and equivalent examples come from some Late Pleistocene caves with Neanderthal remains in Southwest France, and also in Monte Circeo, Italy. Moreover hyenas use to break bones with high intensity (Palmqvist et al., 2011). According to low fracture level in the Sima de los Huesos fossil association perhaps hyena was not the main bone-cracking producer. On the other hand, the carnivore taxonomic diversity found in Sima de los Huesos is particularly high likely corresponding to high ecosystem productivity, although the absence of specialized large scavengers, such as hyaenas, is striking (García, 2003). Therefore we have to suppose that there was high carnivore biodiversity at Atapuerca range. In any case, carnivore who made bite marks over human remains at Sima de los Huesos site is not clear (Andrews & Fernández-Jalvo, 1997; Fernández-Jalvo & Andrews, 2001) but some authors think that Panthera leo fossilis and Vulpes vulpes were probably carnivores which produce the main bite marks (Bermúdez et al., 2004). At the moment we can say that incisions over human bones were caused by wolves, foxes and some big feline that had access to the remains before (Andrews & Fernández-Jalvo, 1997; Fernández-Jalvo & Andrews, 2001). Therefore, a big feline brought the human remains inside or near the cave for feeding. However if felines were the first to eat the human meat, how are they so scarce in Sima de los Huesos shaft? In addition, the most important thing, how did they come in the pit and go out from it if Homo neanderthalensis threw the corpses inside the chasm as a ritual demonstration? GEOLOGICAL DATA Some felines, hyenas, or others carnivores, could transport the human remains of the Sima de los Huesos site as prey. This fact raises two questions. First, how did the concentration of bones happen in the cavity? Second, how did predators come in and go out from this pit? The concentration of skeletal remains in caves may be due to continuous supply of corpses for a short period of time, eventual contribution for a long time or low sedimentation rate. The first, continuous supply of dead bodies is common in colonial animals. An example of this are bats (Andrews, 1990), but the hunter-gatherers current population density is very low (Jones et al., 1992; Howell, 1979) as well as social predators as wolves and felines (Vicente et al., 1999). Predators need large areas for survival which involves a very low population density. On the other hand, the absence of cut marks in Sima de los Huesos bones indicates that there was not a substantial hominid colony inside or near the pit. Therefore, the concentration of corpses in the cave was given by other processes. The second reason for the concentration of bones, slight remains contribution for long periods, has many examples like feeding regurgitation by owls and eagles (Andrews, 1990), feeding troughs (Brain, 1958), falls into trap chambers (Morris, 1974; White et al., 1984; Andrews, 1990), troughs (Vrba, 1980) and hibernating places (Kurtén, 1958; Kurtén, 1976). Falls inside the pit and feeding troughs were an easy interpretation for human remains in the Sima de los Huesos outcrop. The cave morphology with a chasm at the end of a dark gallery and the bite marks in bones could indicate these interpretations but the low skeletal fractures rate observed are not contingent with falling into the Sima de los Huesos deep pit (Andrews & Fernández-Jalvo, 1997; Fernández-Jalvo & Andrews, 2001). The third context, low sedimentation rates, allowed the observed concentration of bones. Cave clays belong to limestone non-soluble fraction. Cavities are due to calcium carbonate dissolution. High percentage of limestone is soluble in water, but a small part of clays are not. Therefore, clay generation during a cave formation is scarce. Therefore karst cavities don’t usually involve rapid burial mechanisms (Smith, 1975; Atkinson & Smith, 1976; Sorriaux, 1982). This context involves the observed low sedimentation rate inside cavities. The idea is simple, many bones inside a low clay percentage produces a level of bones condensation. This new explanation is contingent with three more aspects from Atapuerca site. The first is the observed abrasion in 24 percent of human remains (Andrews & Fernández-Jalvo, 1997; Fernández-Jalvo & Andrews, 2001). The low sedimentation production allowed a high bone transport rate inside karst, which involved the observed bone fragmentation and abrasion. More than 24 % of the bones are eroded by water currents which transported this first fossil assemblage inside the chasm (Andrews & Fernández-Jalvo, 1997; Fernández-Jalvo & Andrews, 2001). These abrasions over fractures was post buried which suggests that these remains was inside sediment and mineralized before the abrasion. In addition, there are bite marks from bears on bears bones but not over human bones. On the contrary, there are bite marks from felines or foxes on human remains but not over bear bones while there are not coprolits in the fossil association. All these reasons indicate that bear and human remains were separated at the first time and was mixed later by debris flows which involved the observed abrasion (Fernández-Jalvo, 2003). Therefore coprolits and phalanges could disappear and spread far away during this water transport. The second reason is the mixed fauna found in the Sima de los Huesos site which happens very often in condensation levels. And the third aspect was the different sedimentation ages found in the outcrop. According to a first sample this age was between 325,000 to 205,000 years old (Parés et al., 2000), but another measure proposed an age between 400,000 to 500,000 years old (Bischoff et al., 2003; Bermúdez de Castro et al., 2003). Condensation levels mix fossils from different ages as in the Sima de los Huesos could happen. Perhaps this data dispersion was due to a low sedimentation rate in the Sima de los Huesos pit. Given the actual time scale suggested by palaeomagnetism and uranium thorium, much of this fossil human accumulation would cover a substantial time span, perhaps in excess of 100,000 years. The next problem to solve is how big felines came in and out of the pit. They probably killed young and inexpert humans while canines came later for feeding on human flesh (Andrews & Fernández-Jalvo, 1997; Fernández-Jalvo & Andrews, 2001). Geological data could explain how all these predators and scavengers came inside and escaped from the chasm. Water does not dilute limestone in a karst system entering and exiting through the same place. The cavities formation produced accesses higher than others. Water flows inside by first entrances and escapes by lower. Collapse and debris flows happen during this process burying old entrances and exits. Therefore, there were more accesses in the Sima de los Huesos. Felines and canines came in and went out of the cavity through these old buried caves by slumps. Two entries were described in the Sima de los Huesos site (Arsuaga et al., 1997), but they were discarded by those authors. They believed that these entries were sealed 400,000 years ago. Nevertheless some rocks falling are around the Sima area which involves an old upper entrance during the Middle Pleistocene (Carbonell & Mosquera, 2006). Nowadays there is no age data about it and the slump age is not studied. In fact, at the end of the excavation in the Sima de los Huesos we will see new entries very probably. We can suppose that all those cavities were the access at that time, explaining entrances and exits of felines to the pit or a feeding place around the cave which produced the primary accumulation transported and reworked by water currents later. This interpretation explains the absence of herbivores in the Sima site. If those big felines haunted herbivores they would kill them in the plains around the current Atapuerca range. Herbivores don’t stay a long time inside mountains and forests because they prefer open fields to avoid predators and inside caves there is not grass for them. On the other hand, large predators as lions, leopards and hyenas move corpses hundred meters (Schaller, 1972; Kitchner, 1991; Bailey, 1993). All these reasons explain the absence of herbivores in the Sima de los Huesos fossil association. This context was different for hominids because they frequently lived near the range caves and they were potential victims for large predators near these cavities. This interpretation also explains the greater abundance of bears at the top of the fossil formation. When the pit was closed by slumps, the only mechanism of bear bone contribution was accidentally falling by hibernation. Similarly, the greater abundance of hominids in the bottom of fossil formation could occur while the lower or upper access remained opened with predators bringing corpses inside or around the chasm. All these bones were reworked by water flows. The lack of phalanges and the abrasions over 24 percent of the remains indicate a selective transport and an intense reworking of fossil association after initial burial (Andrews & Fernández-Jalvo, 1997). These authors interpret the Sima de los Huesos remains as a mixture of different fossil associations (Fernández-Jalvo & Andrews, 2001) and probably with different ages (Rabadà, 2007). The water passage along caves during heavy rainfall events would involve the dispersion, mixing and abrasion observed on these skeletal remains. On the other hand, these water currents dispersed and destroyed carnivore coprolites which are an indicator of carnivore den or feeding place. The only one hand axe found in the Sima de los Huesos site could be reworked with the rest of skeletal remains. Traceology studies reveal that the hand axe does not show use-wear traces because there is microscopic erosion on the edges of the hand axe. According to experimental data, this abrasion seems to have been produced by sandy sediments (Carbonell & Mosquera, 2006). Therefore, this hand axe was not a symbolic object, it was a reworked element as the rest of human remains. CONCLUSIONS A monolithic interpretation does not explain natural processes because these are consequences of a network of causes. The Sima de los Huesos fossil association was considered only as a human burial site by other authors, but according to geological, taphonomical and paleoecological data this outcrop was originated by different taphonomical mechanisms. Competition between Homo and other predators for the cavity, accidental death by falling into the pit and a feeding trough for predators while the cave had other entrances blocked nowadays explain this fossil association. Furthermore, there could have been time differences between bears, humans and others bone remains accumulations events. The bears fell by accident or died while hibernating there. Homo could suffer the same fate but they were more probably victim of large predators that carried the corpses inside or around the pit. Foxes and other scavengers came later for feeding. The water flows in the karst during heavy rainfalls produced dispersion, mixing and abrasion in all these skeletal remains. During all these processes a low sedimentation rate produced the observed fossil concentration. The possible presence of partial and articulated human skeletons in future excavations at Sima de los Huesos site should not involve any problem with the interpretation from this paper because humans could fall down too inside the chasm as bears did. Human falling could involve articulated and complete bodies. REFERENCES Andrews, P. 1990. Owls, Caves and Fossils: predation and accumulation of small mammals bones in caves with analyses of the Pleistocene cave faunas from Westbury-sub-Mendip, Somerset, UK. British Museum (Natural History). London. 231 pp. Andrews, P. & Fernández-Jalvo, Y. 1997. Surface modifications of the Sima de los Huesos fossil humans. Journal of Human Evolution, 33, 191-217. Arsuaga, J.L. 1999. El Collar del Neandertal. Col. "Tanto por saber". Ediciones Temas de Hoy. Madrid. 311 pp. Arsuaga, J.L. & Martínez, I. 1999. La Especie Elegida. Col. "Tanto por saber". 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L’Anthropologie, 107, 1-14 Carretero, J.M., Rodríguez, L., García-González, R., Arsuaga J.L., Gómez-Olivencia, A., Lorenzo, C., Bonmatí, A., Gracia, A., Martínez, I. & Quam, R. 2012. Stature estimation from complete long bones in the Middle Pleistocene humans from the Sima de los Huesos, Sierra de Atapuerca (Spain). Journal of Human Evolution 62, 242-255. Domínguez-Rodrigo, M. 1994. La formación de las acumulaciones óseas de macrofauna: revisión de los criterios de discernimiento de los agentes biológicos no antrópicos desde un enfoque ecológico. Zephyrvs, XLVI, 103-122. Eaton, R.L. 1994. Interference competition among carnivores: A model for the evolution of social behaviour. Carnivores 2, 9-16. Fernández-Jalvo, Y. 2003. Tafonomía en la Sierra de Atapuerca, Burgos (España). Coloquios de Paleontología, Vol. Ext. 1, 147-162 ISSN: 1132-1660. Fernández-Jalvo, Y. & Andrews, P. 2001. Atapuerca, le conte de deux sites. L’Anthropologie, 105, 223-236. García, N., 2003. Osos y otros carnívoros de la Sierra de Atapuerca. Fundación Oso Asturias, Oviedo. García, N. & Arsuaga, J.L. 2011. The Sima de los Huesos (Burgos, northern Spain): palaeoenvironment and habitats of Homo heidelbergensis during the Middle Pleistocene. Quaternary Science Reviews 30, 1413-1419 Haynes, G. 1980. Evidence of carnivor gnowing of Pleistocene and recent mammalian bones. Paleobiology, 6(3), 341-351. Haynes, G. 1983. A guide for differentiating mammalian carnivore taxa responsible for gnaw damage to herbivore limb bones. Paleobiology, 9(2),164-172. Hill, A. 1979. Disarticulation and scattering of mammal skeletons. Paleobiology, 5(3), 261-274. Howell, N. 1979. Demography of the Dobe !Kung. Academic Press, New York. Hutson, J. M. 2008. Reanalysis and reinterpretation of the Kalkbank fauna accumulation, Limpopo province, South Africa. Journal of Taphonomy 6 (3-4), 399-428. Jones, N., Smith, L., O'Connell, J., Hawkes, K. & Kamuzora, C. 1992. 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Hominid Evolution. Lifestyles and Survival Strategies. Schwelm: Archaea, 543-562. Weigelt, J. 1989. Recent Vertebrate Carcasses and their Paleobiological Implications. University Chicago Press, Chicago 188 pp. White, J.A., McDonald, H.G., Anderson, E. & Soiset, J.M. 1984. Lava blisters as carnivore traps. In: H.H. Genoways & M.R. Dawson (eds): Contributions on Quaternary vertebrate paleontology: a volume in memorial to John E. Guilday. Carnegie Museum of Natural History, 8, 241-256. Pittsburg.

viernes, 10 de febrero de 2012

ZAPATERO CONSELLER VITALICI?

Acaben de nomenar a José Luís Rodríguez Zapatero amb un nou càrrec vitalici com a mèrit per la seva vàlua. Ara patim retallades, ben repartides o no, pel deute contret pels anteriors responsables de la gestió del país, el senyor Zapatero i els seus socis econòmics i polítics. Mentre la crisi econòmica sorgia prop el 2008, i mancaven fons per pagar obres i càrrecs, el Govern d’aquests va crear el Plan E demanant grans crèdits a bancs. Això va provocar els dèbits que ara el poble ha de pagar a entitats estrangeres. No puc entendre que després d’aquesta nefasta gestió dels nostres impostos el senyor Zapatero sigui ara nomenat Conseller amb caràcter vitalici del Consell d’Estat alhora que cobri el seu sou, vitalici també, com expresident. Aquest doble premi, primer un despatx com expresident i després un càrrec de conseller mai passarien en una empresa privada. Ell i el seu Govern varen portar a l’actual ruïna les arques estatals. La classe política surt massa sovint indemne de les seves arriscades empreses. En una companyia privada si un alt càrrec provoca una fallida fraudulenta se’l porta a tribunals i no pas se li regala un nou càrrec amb un bon sou. Si això no servís per a un fiscal, resta el delicte d’errors de forma en la tramitació de lleis i el seu conseqüent traspàs de diners la qual cosa el senyor ZP sabia al conèixer els PIB respectius i el deute tan extrem que estava contractant. I si això no fos suficient sempre podem estirar de la jurisprudència ja que a Islàndia estant processant a un alt càrrec del govern, al senyor Geir Haarde, per negligència en el col•lapse econòmic d’aquell país. Però, i si les raons exposades no fossin suficients, sempre ens queda el que sempre resta molt allunyat de les lleis, el nostre sentit comú que ens diu que injust que resulta aquest món entre una classe política d’intocables i un poble que els hi paga el sou, els errors i els regals quan deixen el seu càrrec.

jueves, 9 de febrero de 2012

SOLUCIONES A LA CRISIS IV

Si usted decide invertir sus ahorros puede que le ofrezcan productos financieros con siglas como derivados, preferentes, futuros, CDS o creditt default swap , VaR o value at risk, MBS o mortage-backed securities y CDO o collateralized debt obligations, ¿se ha enterado en qué invertirá su capital? Aún así, y si decide entregar sus euros, deberá armarse de fe y confiar en un banco o entidad financiera bajo una religión llamada codicia. Parece extraño y sospechoso que se hayan creado tantos productos financieros que nada dejan en claro dando sólo trabajo a unos gestores de dinero que nada producen para el país. Con su inversión no se fabricará nada, sólo se especulará con humo, algo que no crea ni lugares de trabajo ni solivianta la crisis vigente. Parece obvio que una manera de solucionar esta crisis es regular los productos financieros y las inversiones como ya se hacía antes de los años 80. Ello era eficaz para evitar la codicia de los mercados, el enriquecimiento de pocos y el paro de muchos. Obama lo prometió antes de ser presidente consciente que ese liberalismo salvaje fue el culpable de la actual crisis económica. Por desgracia, y una vez presidente, se ha rodeado de los altos cargos de las mismas financieras a quien quería regular. Conclusión, todo cambia para que nada cambie.