Archaeological site analysis and interpretation can be a very subjective thing, which is why it’s imperative to gather as much information as possible, especially when trying to determine whether specific activities were practiced. However, all recoverable remains are dependent on the buried environment or soil conditions. For example, whereas pottery can be found on most sites, organic material has usually decayed, although charred or burnt material, pollen and phytoliths are the exception, as are organic remains buried in waterlogged or especially dry environments. So with this in mind, the following is a list of material remains that might indicate domestication at ancient sites.
Evidence for the domestication of crops/plants
1. Pollen - By analysing pollen it is sometimes possible to envisage the wider environment, such as whether a site is surrounded by woodland or open grassland. If the latter, then this might indicate that the land was cleared for growing crops, whilst a high proportion of tree pollen would not. It can also be used for identifying individual species, but cannot differentiate between wild and domestic, except in the case of some cereals. It should also be noted that pollen blown in from some distance could skew the results.
2. Charred remains - The accidental burning of crops/plants (cereal grains for instance) during the preparation or processing of food, can be an invaluable indicator of site domestication.
3. Buried land surfaces - Buried land surfaces can sometimes reveal evidence of ploughing. Such surfaces tend to be preserved under manmade structures, burial mounds being a prime example.
4. Tools - Implements used in the processing of crops/plants are usually a very good indication of domestication, such as quern stones, a device used for grinding cereal grains into flour.
5. Storage facilities - These may take the form of pits or evidence for buildings raised on stilts (possibly as a means of deterring pests). At Butser experimental Iron Age farm, it was shown that sealed pits offered the best form of storage.
6. Latrines - Human faeces can provide an invaluable insight into diet, and whether the food eaten was from domestic or wild sources. However, it does not necessarily mean that the food was local, and could in fact be the result of trade or importation.
7. Pottery - Sometimes plant material unintentionally adhered to the wet surface of a pot prior to firing, and afterwards remained as an impression in the clay. If the impression is of a domesticated species, then it could be argued that the plant was grown locally by the sites inhabitants.
8. Phytoliths - Phytoliths are minute particles of plant silica that come in a variety of different shapes and sizes, depending on the plant, so that domestic varieties are usually quite distinct. They can be found imbedded in pottery, or in places where crop/plant processing was carried out, such as hearths, and like pollen, they can survive in most conditions.
9. Non-indigenous crops/plants - Varieties that are not native to the environment in which the site is found could be regarded as domestic imports, although this cannot be taken for granted, as the ancient distribution of plant species is not fully understood.
10. Human remains: Human teeth were particularly prone to wear from eating quern ground flour, because the bread it produced contained a fine stone powder.
11. Waterlogged material - Organic matter can be found in a remarkable state of preservation if buried in waterlogged (anaerobic) conditions. This is because the absence of air delays or stops the process of decay, so that domestic crops/plants, or associated wooden tools, are likely to survive intact.
Evidence for the domestication of animals
1. Bones - In some cases the skeletal remains of domestic animals can be noticeably different to their wild cousins, the pig being a very good example, as domestic pig teeth tend to be far smaller. It is also possible to spot stress in the bones of animals used for heavy labour, such as oxen or cattle for ploughing.
2. Age and sex - By determining the age and sex of an animal it is sometimes possible to deduce whether the remains were domestic or wild. For instance, a bone assemblage of predominantly young animals might indicate that they were kept primarily for their meat and hides, especially if they were male. Whereas older animals, especially females, might indicate they were kept for breeding, or if cows or goats, milk.
3. Tools - Finding a yoke or plough would be a strong indication of domestication, as would a horses bit.
4. Non-indigenous animals - The sudden appearance of animals that were not native to the area, might indicate the arrival of a new domestic breed, such as the introduction of sheep into Britain.
5. Phosphates: Animal manure leaves behind phosphates in the soil, which can remain there for sometime. So when this is found in abundance, it could be used as evidence for specialist structures, such as livestock enclosures, and therefore domestication. However, geochemical prospection is very expensive and tends to be used sparingly.
The above is far from being a comprehensive list, and for those who would like to know more about this subject, or archaeology in general, then a good all round authority is Renfrew and Bahn’s ‘Archaeology: Theories, Methods and Practice’, published by Thames and Hudson Ltd of London.