Anthropology Chapter 6

Interpreting the context of Macrobotanical Remains

Archaeologists want to know about the human use of certain plants in hunter-gathering communities as well as agriculture: what plants were important to diet? How were they gathered and grown, processed, stored, and cooked? To do this one has to understand the processes that these plants went through and what effects the processes had on them. Often the plants reveal the nature of a context and not the other way around.

Domestication of Wild Plant Species

Archaeologists want to know when humanity started adapting plants for their own personal gain. Often, it is very difficult to tell when a plant is wild and when it has been domesticated, but in some cases a clear distinction can be made. Evidence of this can be found in seeds and through an observed loss of atomical structure in the plant.

Other Sources of Evidence

Art and texts, even early photographs.

Plant Residues

Can give some idea of what species were available - pottery vessels themselves contain plant fibers as tempering material.

Chemical Residues in Plant Remains

Certain chemical survive in plant remains which provides another way to identify them - proteins, fatty lipids and DNA.

Remains of Wood

Charcoal (burnt wood) is a very durable material and is commonly found by the archaeologist during excavation. Charcoal and charred seeds have proved to be the most reliable material from which to take samples for radiocarbon dating.

Deducing Age, Sex, and Seasonality from Large Fauna

Classifying the sex is easy in the case than an animal has antlers, large canines, where a penis bone is present, and differing pelvic structures. Measurements of certain bones can also indicate gender. Age of the animal can be decided from the degree of closure of the sutures in the skull, or to an extent, development of limb bones. Estimates of the age when animals were killed are based upon eruption and wear patterns of the teeth. Seasonality can be determined by identification of species available at only certain times of the year such (ex: certain animals shed antlers at a specific time in the year).

Plant Impressions

Common in fired clay - proves that a species in question was present at the spot where the clay was worked. The impression however does not prove that the plant was important to society. Sometimes plants were purposely marked on clay, such a wheat, which could over-emphasize its importance.

Lovelock Cave, Nevada

Contains preserved feces from 2500-150 years ago and yielded remarkable evidence about diet.

Animal Domestication

Crucial to the most important developments in history - in some cases animal domestication is obvious in that a new species is introduced to an area by humans. When an animal is domesticated, humans interfere with the natural breeding pattern which has led to changes in the physical characteristics of that species from their wild state. Certain tools can indicate domestication such as plows, yokes and horse trappings.

Plant Evidence from Literary Societies

Evidence is written in documents and displayed in art. Herodotus for example gives plenty information about eating habits in the fifth century, notably Egypt. Though the writings are useful, they view human diet in short-term while archaeologist view diet with a long-term perspective.

Ancient Winds

Isotopes can also say something about winds in different periods. Isotope O-18 and O-16 give a ratio which makes it so the temperature difference can be calculated because that place and the equatorial region. Rain drops found in hurricanes allow scientists to trace but when a hurricane took place and create a record back to tens of thousands of years. Wind has impacted the migration of several peoples.

Proving Human Exploitation of Animals in the Paleolithic

Many mistakes have been made in the past by assuming all animal remains by a site are part of the human diet - archaeologist check bones for marks of stone tools. Much work is going in to differentiating marks from other traces such as scratches and punctures made by animal teeth, etching by plant roots, abrasion by sedimentary particles or post-depositional weathering, and damage by excavation tools. It turns out that microscopic features alone are not enough and context of the finds as well as position of the marks need to be studied as well.

Fecal Material

Many organic remains can survive surprisingly well after their journey through the human digestive tract - feces survive rarely and only in very dry sites or very wet sites. Feces are a very important indication of what people ate in the past - remains of bone fragments, plant fibers, bits of charcoal, seeds, remains of fish, birds and even insects have been found in waste. Since fecal residues represent only a single meal, they provide short term data, unless found in great quantities.

Macrobotanical Remains and diet

May be desiccated, waterlogged or preserved by charring - charring is the principle and sometimes only cause of preservation on habitation sites. Numerous samples over time are needed to know what species were exploited, their importance and their use during a time period.

Macrobotanical Remains

Nonmicroscopic plant remains recovered from an archaeological site - sediments are screen and plants are retrieved because they float on the surface of water.

Pollen Analysis

Paynology, or the study of pollen grains was developed by Lennart von Post at the beginning of the 20th century. It is valuable because it provides information of chronology as well as environment and forest clearance. Although it cannot produce an exact picture of a past environment, it does give some idea of fluctuations in vegetation. It also provides information for environments as ancient as 3 million years old. Pollen has an almost indestructible outer shell and can survive for ten of thousands of years.

Plant Residue on Artifacts

Phytoliths can show what type of grasses were cut by a certain tool and microscopic study can identify plant fibers. Certain chemicals can be placed on a surface and will have a reaction if certain substances are on that surface. Chromatography is used on lipids to differentiate fats that are found.

Reconstructing the Plant Environment

Plant studies are meant to reconstruct what the vegetation was like in any past time period or place. Plant communities of a given area and period provide clues to local animal and human life and also reflect soil conditions and climate. Pollen is a huge contributer to plant evidence.

Macrofuana

Remains of large animals found on archaeological sites - helps archaeologists build a picture of past human diet. As environmental indicators however, they have proved less reliable because they are not as sensitive to environmental changes as small animals and because human placement has a lot to do with where some bones are found. Teeth of large animals tell us about diet, therefore type of vegetation. However, often that is not a good indicators because herbivores thrive in a wide range of environments and eat a variety of plants - can also be used to determine in which seasons of the year a site was occupied.

Isotopic Methods: Diet over a Lifetime

Reveals a great deal about long-term food intake: relies on reading the chemical signatures left in the body by different foods. Plants can be separated into 3 groups based on their differing ratios of two carbon isotopes: temperate land plants, tropic land plants, and marine plants. As these foods are consumed, chemical signatures are passed along the food chain and are eventually fixed in human and animal bone. Only archaeological evidence however can provide specifics on species.

Diatom Analysis

Single-cell algae that have cell walls of silica instead of cellulose so their cell walls survive after the algae die. They accumulate in large number of any body of water in which they live and are most commonly found in lake and shore sediments. Can be used to identify when lakes became isolated from the sea in area of tectonic lift.

Microfauna

Small, often microscopic animals, especially those that live in the soil. They are more sensitive to climate change and adapt quickly - reflect the immediate environment more quickly than larger animals. Small animals are found in greater numbers than larger ones, which improves statistical significance of analysis. Insectivores, rodents and bats are found on archaeological sites, but it is necessary to make sure that their bones were deposited at the same time due to burrowing. Bones of fish and birds can be used to determine the season in which particular sites were occupied.

Stomach Content

Stomach tend not to survive in archaeological contexts, except in bogs. Some mummies also provide dietary evidence. While this information can be useful, they do not necessarily indicate every day diet. Victims were possibly executed or sacrificed indicating that their last meal might have been out of the ordinary.

Human Teeth as Evidence for Diet

Teeth survive well because they are made of the two hardest tissues in the body. Examining the microscopic marks on teeth can indicate evidence for the sort of food that people enjoyed. Striations on teeth can indicate what kind of food has been consumed. Earlier teeth indicated that meat and chewing was more common while cooking and less meat consumption followed in more civilized eras. Tooth decay can also provide dietary information.

Remains of Individual Meals

The most direct kind of evidence of what people ate - At Pompeii, meals of fish, eggs, bread and nuts were found on the tables, as well as food in shops. Much food in found in funeral contexts such as tombs. Although meal remains can tell us what was eaten on a certain day, only actual human remains reveal what was eaten habitually.

Evidence from water and ice:

The sediments of the ocean floor only grow centimeters every thousand years, but those those centimeters contain thousands or even millions of years of climate history. Cores are extracted from the seabed and fluctuations in the species are recorded to find a sequence. Cores are also extracted from stratified ice sheets and the oxygen isotopic composition provides a guide for climate oscillations. It is also possible to analyze bubbles of ancient methane gas trapped in ice. Variation of oxygen and hydrogen isotopic compositions reveal the temperature when ice was formed.

Paleoentomology

The study of insects from archaeological contexts. The survival of insect exoskeletons, which are quite resistant to decomposition, is important in the reconstruction of paleo-environments.

Archaeozoology/Zooarchaeology

The study of past human use of animals.

Paleoethnobotany

The study of past human use of plants.

The source of direct evidence for what people ate:

The study of stomach content, fecal matter and bones.

Microwear Analysis

The study of the patterns of wear or damage on the edge of stone tools, which provides valuable information on the way in which the tool was used.

Phytoliths

Tiny silica particles contained in plants. Sometimes these fragments can be recovered from archaeological sites even after the plants themselves have decayed. They can be found in hearths, ash layers, pottery, plaster and even on stone tools and the teeth of animals. They are useful because they are produced in large numbers and survive well in ancient sediments with distinctive shapes that vary according to type. Phytoliths often survive in sediments that are hostile to the preservation of fossil pollen and may be the only things that provides evidence for paleoenvironmental or vegetational change.

Tree Rings and Climate

Tree rings have a growth that varies with the climate - growth is strong in the spring and declines to nothing in the winter. The more moisture available, the wider the annual rings gets. A tree grows slowly when it has a dense forest cover and quickly when the forest is light. However, temperature and soil moisture tend to be the most dominant thing to affect tree growth. It is much more effective than evidence water and ice give and proves that organic materials give the most accurate evidence.

Seeds and Fruit

Used to identify species, despite changes in their shape caused by charring or waterlogging.

Subsistence and Diet

What people extracted from an environment/how people subsisted. Meals = what people ate at a particular time, Diet = what people consumed over a long period of time. Some of the diet can be discovered by bones which can indicate the balance of marine and terrestrial food and even show differences in nutrition between members of a society. Interpretation of food can be problematic and required complex procedures. The only way of proving that a plant or animal was actually part of the diet the presence of its traces in stomach content or ancient fecal matter. If neither of those are present, archaeologists look at the bones so see if they are cut or burned indicating an animal would have been butchered and cooked.