Neanderthal Life: El Sidrón

Stereotypes of Neanderthal life abound. Facts are limited to what can be deduced from the bones and stones they left.

Remains of twelve individuals from 49,000 years ago were found at El Sidrón, in the Cantabrian range of Asturias in northern Spain. That’s during the devastating cold spell mentioned in the post for 29 July. Evidence suggests the Neanderthals were eaten, and their bones left together. They later fell through an opening when the limestone cave’s roof collapsed, probably during a flood.

The twelve must have been members of a single band composed of three adult men and three adult women, along with two teenage males, and a male child. The genders of the other adult, the other teenager and the infant couldn’t be determined.

The three men were brothers. The women were not related, and had come to live with the band. One adolescent and one of the children were brothers, born about three years apart. No comment has been made on the absence of young girls in the group.

It’s likely the band had moved outside its ancestral range in northern Europe, and interbred with people already in the south. A jaw bone had the character of northern Neanderthals, while the faces showed the broadness and lowness associated with southern ones.

The climate was cold and dry. In Catalonia to the east, Francesc Burjachs and Ethel Allué found pollens from composites, sage brushes, and grasses in those millennia. Scattered Scots pines survived in the dry steppes.

Yarrow was surely one of the composites. One subspecies, Ceretanica, is a relic of the Pleistocene Pyrenees. Achillea millefolium spread into North America from a refuge in Bergenia and, today, grows nearly everywhere from the far north of the Yukon to Honduras. You sometimes see it here along the roadside.

Few animal bones were found among the litter at El Sidrón. Antonio Rosas’ team identified a red deer with "very few small mammals and gastropods." When Karen Hardy’s group examined plaque from the Neanderthals’ teeth, they found "few lipids or proteins from meat."

The teeth showed signs of dietary deprivation, often from the fourth and twelfth years of life. The enamel of five individuals indicated they’d been malnourished twice and one person had suffered four times. One of the adolescents had lived through "an exceptionally severe episode of physiological stress"

In the absence of meat they were relying on plants. Hardy’s team found the plaque contained "a
range of carbohydrates and starch granules." They also found "evidence for inhalation of wood-fire smoke and bitumen or oil shale." The starches were so changed by roasting, they couldn’t be identified.

Roasting requires close contact with fire. Perhaps they used sticks to manipulate foods. Yarrow is slow to ignite, and stays green in most winters. It might have been grasped like a potholder for protection.

No wooden tools have survived from El Sidrón. The ones found were stone. The only adaptation to changed circumstances was most used local chert. A few were fashioned from quartzite.

Burns must have been a problem. The two plants Hardy’s team could identify, yarrow and camomile, have both been used to treat burns and other skin injuries. They were probably chewed raw and either spat onto the wound, or the wounded finger was sucked. It’s been used that way in recent times by the Zuñi in New Mexico, the Crow of Montana, the Cree of Saskatchewan, and the Bella Coola of British Columbia.

The chewed plant has been used to treat toothaches by the Cree and Paiute. Rosas’ colleagues found one of the El Sidrón individuals at had had an abscess caused by periodontitis associated with biting hard. They noted, "This sort of lesion is common among Neandertal lineage populations."

The other physical problem Neanderthals were known to have, broken bones, wasn’t mentioned for El Sidrón. Elsewhere, Thomas Berger and Erik Trinkas found nearly all the bodies that survived showed signs of fracture and healing. Most had three or four wounds, primarily to the upper body. The trauma pattern closely resembled injuries suffered by today’s rodeo competitors.

Trinkas noted, they didn’t find any broken leg bones among the Neanderthal relics. That kind of injury must have been fatal in a mobile band. No broken bones in a band meant they either weren’t eating meat, were left behind or, possibly, were eaten.

Notes: Red deer is Cervus elaphus, sage bush is Artemisia, Scots pine is Pinus sylvestris, chamomile is Anthemis nobilis. Generic yarrow is Achillea millefolium, the Pyrenees subspecies is Achillea millefolium ceretanica.

Aleksoff, Keith C. "Achillea millefolium," 1991, in U.S. Department of Agriculture, Forest Service, Fire Effects Information System.

Burjachs, F. and E. Allué. "Paleoclimatic Evolution During the Last Glacial Cycle at the NE of
the Iberian Peninsula," in María Blanca Ruiz Zapata, et alia, Quaternary Climatic Changes and Environmental Crises in the Mediterranean Region, 2003.

Hardy, Karen, Carles Lalueza-Fox, et alia. "Neanderthal Medics? Evidence for Food, Cooking, and Medicinal Plants Entrapped in Dental Calculus," Naturwissenschaften 99:617-626:2012; quotation on smoke.

_____. Discussed by Matt Kaplan in "Neanderthals Ate Their Greens," Nature website, 18 July 2012; quotations on lipids and starches.

Hirst, K. Kris. "El Sidrón - Evidence for Neanderthal Cannibalism in Spain," About Archaeology website.
Lalueza-Fox, Carles, Antonio Rosas, et alia. "Genetic Evidence for Patrilocal Mating Behavior among Neandertal Groups," National Academy of Sciences, Proceedings 108:250-253:2011.

Moerman, Dan. Native American Ethnobotany, 1998, summarizes data from a number of ethnographies.

Rosas, Antonio, Carles Lalueza-Fox, et alia. "Paleobiology and Comparative Morphology of a Late Neandertal Sample from El Sidrón, Asturias, Spain," National Academy of Sciences, Proceedings 103:19266-19271:2006; quotation on dietary stress.

Trinkas, Erik. Quoted in "Evidence Suggests Skulduggery among the Neanderthals," The Washington Post, 23 April 2002.

_____ and T. D. Berger. "Patterns of Trauma among Neadertals," Journal of Archaeological Science 22:841-852:1996

Neanderthal Tools: La Cueva de los Aviones

Neanderthals, especially those inhabiting areas to the north of the Iberia peninsula, relied primarily on flint for their tools. Paul Mellars noted a strong "coincidence between raw material distributions and the occurrence of the richer and more intensively occupied open-air sites" in southwestern France. In Spain, flint nodules only occurred in the area of Cap Salou on the Catalonian coast.

When flint wasn’t available, tool makers substituted chert, a similar silica rock. Its primary location in Spain was the Jurassic layers in the Sistema Ibérico.

Perhaps because flint wasn’t as widely distributed as the animals they hunted, early Neanderthal tool makers developed techniques that produced more flakes from a nodule than previous methods. Once formed, Jean-Pierre Bocquet-Appel and Alain Tuffreau said, Mousterian technology didn’t change.

Southern Neanderthals who sought refuge in southeastern Spain during the cold spell 50,000 years ago still used flint for sidescrapers and points, but were forced to adapt quartz for their other tools. Their diet also expanded to include local species. They left behind marine mollusk shells and rabbit and tortoise bones along with those of horses, deer, and ibex.

La Cueva de los Aviones was less than five miles from the Mediterranean. João Zilhão’s team found the local Neanderthals not only ate local varieties of cockles, mussels, and limpets, but also some that weren’t local. They believed they must have wrapped the dog whelks in algae to prevent them from spoiling on the journey back to the cave.

The archaeologists noticed that some of the shells they found were from inedible species. Many had holes from 4.5 mm to 6.5 mm in diameter. While nature and weather could have produced holes, they believed these specific clam shells were selected because they could be strung into ornaments.

Glycymeris nummaria shells are nearly circular with a diameter that can reach 2.4 inches across. According to Wikipedia, they’re marked by radiating, concentric lines. The exterior is dull, usually a dark or pale brown. The inside is " glossy, white or pale yellow, often with irregular brown markings."

Hematite residues were found on one of the clam shells. Researchers found the nearest source for the iron oxide was two or three miles away in the modern mining district of La Unión.

More interesting than the ornamental clam shell was a spiny oyster shell that had contained "a red lepidocrocite base mixed with ground particles of charcoal, dolomite, hematite, and pyrite." Zilhão’s group thought it was either used for mixing or storing pigments.

The existence of a container implies the development of one of the necessary concepts that allowed individuals to move beyond being dependent on what was found each day to storing food for later use and for boiling it.

Notes:
Bocquet-Appel, Jean-Pierre and Alain Tuffreau (April–June 2009). "Technological Responses of Neanderthals to Macroclimatic Variations (240,000-40,000 BP)," Human Biology 81:287-307:2009.

Gibbons, Wes and Teresa Moreno. The Geology of Spain, 2002; on locations of flint.

Gómez, J. J. and S. R. Fernández-López. "The Iberian Middle Jurassic Carbonate-Platform System: Synthesis of the Palaeogeographic Elements of Its Eastern Margin (Spain)," Palaeogeography, Palaeoclimatology, Palaeoecology 236:190-205:2006; on locations of chert.

Mellars, Paul. The Neanderthal Legacy, 1996.

Wikipedia, on the mollusk species.

Zilhão, João, et alia. "Symbolic Use of Marine Shells and Mineral Pigments by Iberian Neandertals," National Academy of Sciences, Proceedings 107:1023-1028:2010.

The edible local species were:
Cerastoderma - common cockle
Monodonta - sea snail
Mytilus - saltwater mussel
Patella - limpet

The non-local edible species were:
Nassarius incrassatus - thick-lipped dogwhelk
Gibbula - small sea snail

The ornamental species was:
Glycymeris insubrica/nummaria - bittersweet clam

The utilitarian species was:
Spondylus gaederopus - European spiny oyster

Neanderthals

Homo neanderthalensis emerged about 200,000 years ago as a regional species or ecotype of Homo heidelbergensis in Europe. A parallel species, Homo sapiens, was developing at the same time in east Africa. Neanderthals evolved into thee subgroups: one in Asia (blue on the map below), one in northern Europe (pink), and one in southern (rust). The boundary between east and west lay in the Caucasus. The last two were divided by the Alps, which were covered at times with glaciers during the Pleistocene.

Anders Götherström’s team found differences between the eastern and western groups increased about 48,000 years ago. The DNA from bones found before that period and those found in the east contained the range of genetic variation one would expect. Those from the west showed much less: .0063 compared with an index of .0191 for eastern Neanderthals and .0270 for species in Africa.

The reduced variation recorded a demographic crisis that occurred when the western population had been severely reduced in size and regrown from a single group or area. Thomas Schmitt has noted that when species expanded from Pleistocene refuges they exhibit "only weak genetic differentiation during the process of range expansion."

Götherström’s group noted the break in Neanderthal genetic continuity occurred after ice bergs breaking from the Greenland ice sheet added cold, fresh water to the north Atlantic. The altered ocean currents brought frigid conditions to western Europe.

Hartmut Heinrich was the one who first observed the changes in ocean core sediments that occurred when ice bergs calved. The fifth such episode has been dated to 50,000 years ago by Gerald Bond’s team. Mark Maslin’s group thought the rafting was fairly rapid and each episode probably lasted less than a thousand years. That’s still 50 generations that reproduce every 20 years.

Quick change is difficult for plants, animals, and their dependants. Götherström’s colleagues hypothesized the western Neanderthals that survived were those who moved into protected refuges from which they emerged when climatic conditions improved.

During the ice age, there were three major European protected areas for species fleeing the spreading glaciers: the Iberian, Italian and Balkan peninsulas (the R's on the map below). Schmitt has reviewed their ranges, which include small mammals, insects, and plants. Within the Spanish peninsula, he noted one nursery area was in the southwest. The other in the southeast had some connections to the maghreb of northern Africa. The refuges roughly coincide with the distribution of southern Neanderthals.

Notes:
Bond, Gerard, et alia. "Correlations Between Climate Records from North Atlantic Sediments and Greenland Ice," Nature 365:143-147:1993; date for Heinrich event 5.

Fabre, Virginie, Silvana Condemi, and Anna Degioanni. "Genetic Evidence of Geographical Groups among Neanderthals," PLoS One, 15 April 15, 2009.

Götherström, Anders, Thomas P. Gilbert, J. Carlos Díez Fernández-Lomana, Eske Willerslev, and Juan Luis Arsuaga. "Partial Genetic Turnover in Neandertals: Continuity in the East and Population Replacement in the West," Molecular Biology and Evolution 29:1893-1897:2012.

Heinrich, H. "Origin and Consequences of Cyclic Ice Rafting in the Northeast Atlantic Ocean During the past 130,000 Years," Quaternary Research 29:142-152:1988; cited by Wikipedia. The episodes are referred to as Heinrich Events 5 and 6.

Schmitt, Thomas. "Molecular Biogeography of Europe: Pleistocene Cycles and Postglacial Trends," Frontiers in Zoology, 2007.

Graphics:
1. Delamaison, Manon. "Distribution Géographique des Sites du Moustérien," uploaded to Wikimedia Commons, 15 October 2013.

2. Neanderthal subgroups, from Fabre, above. Pink represents the range of western Neanderthals, blue the east, and gold the southern.

3. Pleistocene refuges, from Schmitt, above. The R’s represent refugia, the H’s diffusion paths for recolonization.

Experiences of Fire

Chemistry dictates there’s only one way to create a fire: heat a carbon containing substance to 400C.

Nature does it by charging electrons until they’re hot enough to flare in bolts of lightning. Such events were more likely to occur in prehistoric Africa than in Europe. Today, the greatest number of cloud to ground strokes occur in the highlands of eastern Congo, the black spot on the map below that lies on the equator.

NASA’s charting shows Europe experiences relatively few lightning strokes. Our part of the country gets a moderate number, but only one of our recent fires was caused by lightening. The Jaroso ran through the headwaters of the Santa Cruz river near Trailrider Wall in 2013.

The other major fires were caused by exposing flammable material to intense heat. The Dome spread from a poorly extinguished camp fire in 1996, the Cerro Grande from a controlled burn in 2000, and Las Conchas from a downed power line in 2011. All occurred during times of high winds, and none were declared out until monsoon rains had drenched them.

In the past, the easiest way to create such a spark was by striking pyrite with something harder like chert or flint. The impact sheered the iron and ignited the sulphur. Pyrite is iron sulfide (FeS₂), flint and chert mainly silicon dioxide (SiO₂).

Our recent experiences have taught us the condition of grass and the spacing of trees makes a difference in the severity of a conflagration. High intensity fires spread when they burn in tree canopies or crowns where heat transfers easily from dried leaf to instantly dried leaf.

On the road to Jémez Springs the trees were so closely spaced in 2000 the grasses at the bases of some could ignite the tops of others. This was probably a rare situation caused by lumbering in the early twentieth century. Trees are not normally so dense nor are they all the same age and height.

Low intensity fires spread along the ground through plants and organic debris. It’s difficult for them to jump from trunk to trunk, because there’s too much oxygen between the two poles of carbon for temperatures to sustain them. Instead, they creep up the trunks, charring as they rise.

At moderate temperatures, ground fires may occasionally flare high enough to torch lower leaves. Usually, the trees are too widely spaced for one canopy to ignite another.

The nature of the grass and underbrush also matter. Few lightening strokes produce fires during the monsoon season when it’s raining. Most occur in the dry spring. One Forest Service scientist, Guido Kaminski, found rotted wood ignited but went out quickly. When cheat grass was heated, "the flame of the pilot jumped across the entire fuel bed, consuming it before the test operator could contain it."

Another Forest Service employee, William Pitts, found a mix of pine needles and recently cut tall, wet-season fescue burned at a lower temperature than the other tested fuels, but the quickest flame occurred with dry-season fescue if there was a wind. He found cheat grass also required wind to burn, and a had tendency to smolder. Needles from loblolly pines were the only kindling that would fire without wind.

After the Cerro Grande fire, people who surveyed the grounds saw areas of ash, iron oxides, and clays where once there’d been trees. The reddened soils were ones where the water-containing iron compounds (iron hydroxides) had become so hot they lost their water and some form of hematite emerged. To produce those results, soil temperatures were at least 480 degrees (250C). The severely burned surface may be sterile for some time.

More common were areas where ground litter burned and only charred logs remain. Here soil temperatures were above the boiling point of water and could have been lethal down 2". Even if only ash were present, there were nutrients left to support seeds that blew in from adjoining areas.

Surrounding them were the scorched trees that hadn’t ignited. Over the nearly 6,000 acres reviewed by Raymond Kokaly’s team, nearly half were ash, char or bare ground. More than 15% were conifer dehydrated by heat. Almost 4% were grasses dried into straw. The rest, 28.9%, were still green.

Randy Balice’s group found, outside the lands managed by LANL, 48.6% of the acres burned at high intensity and 42.6% at moderate temperatures. The remaining 8.8% suffered low intensity heat. Fire intensity and fire severity refer to two different phenomena, the one to chemistry and air temperatures, the other to biological consequences and soil temperatures.

In Africa hominins no doubt also walked through fire scarred lands and saw the effects of heat. They may have observed sticky resins released from partly charred trees and transformations in rocks. They also may have noticed differences in the tastes of plant foods roasted by passing heat and tender rejuvenating growths. They certainly would have recognized any hematite.

When we drive through the damaged lands years after the Cerro Grande, we see curiosities. The hominins were trained to observe rocks and plants.

Notes: Fahrenheit conversions of Centigrade temperatures are rounded for ease of understanding.

Balice, Randy G., Kathryn D. Bennett, and Marjorie A. Wright. Burn Severities, Fire Intensities, and Impacts to Major Vegetation Types from the Cerro Grande Fire, 2004; good maps and pictures.

Kaminski, Guido C. Ignition Time vs Temperature for Selected Forest Fuels, November 1974. He was studying fires caused by sparks from chain saws.

Kokaly, Raymond F., Barnaby W. Rockwell, Sandra L. Haire, and Trude V.V. King. "Characterization of Post-fire Surface Cover, Soils, and Burn Severity at the Cerro Grande Fire, New Mexico, Using Hyperspectral and Multispectral Remote Sensing," Remote Sensing of Environment 106:305-325:2007.

Pitts, William M. Ignition of Cellulosic Fuels by Heated and Radiative Surfaces, March 2007. He was studying fires started by hot mufflers and catalytic converters. Loblolly pine is Pinus taeda. His fescue was Festuca arundinacea.

Graphics: All photographs were taken 4 July 2013 along Route 4 from the entrance to Bandelier National Monument to the base of Cerro Grande. The altitudes are from the camera’s GPS interface.

1. United States National Aeronautics and Space Administration, National Space Science and Technology Center Lightening Team, and the Global Hydrology Resource Center. Data from space-based sensors reveal the uneven distribution of worldwide lightning strikes, 10 December 2001. Data obtained from April 1995 to February 2003. Units: flashes/km²/yr.

2. Ponderosa pine on steep hill, burned so severely, little has come back in 13 years. Altitude: 8049'.

3. Area of charred wood. It looks like a dozer knocked down trees like the one laying in back with short needles. The grasses have not revived in the drought, but shrubs have regrown and the trees in the distance weren’t killed. Altitude: 7054'.

4. Close-up of gambel oak in #3. The trunks were scorched enough to kill the buds buried in the sapwood, but the roots have been able to sucker.

5. Gully was not destroyed and juniper have come back. Other sloping ground in the area is still infertile, but the ponderosa pine on the far bank survived. Trees in the distance, closer to Cerro Grande, are still black specks. Altitude: 7211'.

Fire

Back to life in early Spain for a few weeks.

Archaeologists have problems establishing when hominins deliberately used fire. For a while they believed anything that looked like a heated red sediment indicated combustion had occurred. Then, geologists determined the red color at Schöningen came from iron compounds that formed when the nearby lake dried. Similarly, researchers determined the remains that suggested fire and wood ash in China’s Zhoukoudian cave were actually the natural consequences of "water-deposited organic-rich sediment and colluvial reworking of loess."

Archaeologists believe sediments underlying fires were only reddened when they were heated to 390 to 750 degrees F (200 to 400 Celsius). Now they test artifacts with infrared microspectroscopy to determine the highest temperature to which they’ve been exposed and thermoluminescence dating to determine when. Unfortunately, machines can’t distinguish between temperatures caused by man-made fire, wild fire, or volcanic eruptions.

Fire is a chemical reaction that occurs when carbon molecules are heated in an oxygen environment until the two recombine to create carbon dioxide and water. The point of conversion is the explosion we call combustion.

Not all carbon molecules burn easily. Some are embedded in sacs that make ignition difficult. All grass and wood cells contain cellulose fibers suspended in lignin. Both are organic compounds that contain carbon.

Some tars and resins may alter fire behavior slightly by species. Moisture in the sapwood can slow the process. Relative amounts of lignin and cellulose may differ by plant. But, the

chemistry is absolute. When the temperature of wood reaches the boiling point of water, 212 degrees (100C), chemical bonds begin breaking.

By the time temperatures reach 392 (200C), wood begins losing moisture and releases water vapor.

Between 392 and 572 degrees (300C), lignin loses its liquid chemicals and turns to char. Cellulose does not. Technically it has entered the pyrolysis phase. Charcoal is made by this type of controlled heating.

The temperature at which any organic material can burn depends on the chemistry of the material. The temperature at which it can maintain the combustion without contact with a heated surface is absolute.

Cellulose begins to disintegrate around 660 degrees (350C). Carbon bonds begin breaking around 700 to 750 degrees (370 to 400C).

The ignition point is reached around 750 degrees F (400C). After that, a fire is self-sustaining. The heat from the explosion of molecules warms the air so others can ignite. The more explosions, the greater the generated heat and the greater the number of subsequent explosions.

Before that magic temperature, you can only keep something burning by maintaining contact with something hotter. You use flaming kindling to ignite wood in a camp fire. When people use flame throwers to burn weeds, the tools provide a constant heat source to organic matter too widely dispersed to spread heat. One company advertises the propane-fueled temperature of its thrower is 2050 degrees F.

At 842 degrees (450C) wood cells no longer emit the volatile chemicals that color smoke and poison the air. What remains is char that is converted to carbon dioxide and water, until only ashes remain.

Bones burn differently because their carbon is held in different molecular structures. Several students have tried to reproduce paleolithic fires. A girl in Wisconsin found long bones from white-tailed deer would crack to expose the marrow, which dripped into the flames. The fire temperature varied between 275 (135C) and 200 degrees (150C). She used braided grass for her fuel.

She tried again with ribs and long bones from a deer and long bones from a North American elk. This time the temperature reached a thousand degrees (540C) and produced "calcined (decomposed carbon) bone." She’d used a different local grass with a smaller stem diameter.

A group in Finland tried igniting fresh, unbroken bones of elk, bear and grey seal with "dried pine and birch wood." They found a fire composed of 25% bone and the rest wood had a stable temperature, while one that was 75% bone had one that fluctuated. The latter also did not produce enough heat to burn bones thoroughly.

The four also found ribs burned quickly at a high temperature, while long bones burned "slower but at a more stable temperature for a longer time." When they finished the bear bone experiment, they stacked the bones aside. They found after an hour their temperature was 750 degrees (400C), even though they were cold to the touch.

Archaeologists believe the earliest fire users didn’t yet ignite fires with flint and pyrite. Instead, they perpetuated chance fires by keeping them burning and by carrying miniature fires when they migrated. Terrence Twomey thought they might have carried glowing logs from place to place. The Finnish students implied bones kept at the ignition temperature of 400C would have worked better.

Notes:
Berna, Francesco, et alia. "Microstratigraphic Evidence of in situ Fire in the Acheulean Strata of Wonderwerk Cave, Northern Cape Province, South Africa," National Academy of Sciences, Proceedings 109:E1215-E1220:2012, quote on Zhoukoudian cave.

_____, Mareike Stahlschmidt, et alia. "The Schöningen Hearths: Perspectives on Multidisciplinary Geoarchaeological Research and Middle Pleistocene Fire Use in Northern Europe," Developing International Geoarchaeology Conference, 2013.

Glazewski, Megan. "Experiments in Bone Burning," Oshkosh Scholar 1:17-25:2006.

Twomey, Terrence Matthew. Keeping Fire: the Cognitive Implications of Controlled Fire Use by Middle Pleistocene Humans, 2011.

Vaneeckhout, Samuel, Juho-Antti Junno, Anna-Kaisa Puputti, and Tiina Äikäs. "Prehistoric Burned Bone: Use or Refuse - Results of a Bone Combustion Experiment," International Council for Archaeozoology, international conference, 2010.

White, Robert H. and Mark A. Dietenberger. "Fire Safety of Wood Construction" in USDA, Forest Products Laboratory, Wood Handbook, 2010; defines the stages of wood burning.