Lessons from Lost Habitats - A Basic Understanding of Environmental Archaeology

Having spent almost a decade studying this specific sub-discipline, I think it is time to try and write a non-boring piece on the topic. I use the term ‘non-boring’ here because to most people archaeology is interesting when it involves huge monuments, conspiracy theories including aliens, or has to do with investigating the mythological/ religious scriptures! Even within the archaeological community, environmental archaeology is perceived as a ‘very-science-y’ niche and not many choose to study it. But what exactly does the term mean? How does it help archaeologists reconstruct the past? And just how science-y is it? I will try my best to simplify it. Let’s dive into it! 

Imagine yourself as a Neolithic human. Let’s suppose that you are looking for a place to settle down with your community - you’ve decided that you don’t want to be a hunter-gatherer anymore! You want to farm and cultivate your own food. What resources would you require in order to shift to a sedentary lifestyle? How would an ideal Neolithic-times day or even life look for you? Fast forward a few thousand years later - an archaeologist stumbles upon the ruins of the place you once lived in. What do you think they would be likely to find there? Take a pause and think about it, let me know in the comments! 

(Credit: https://www.cartoonstock.com/directory/n/neolithic.asp)

Now think about the excavated settlements found at present day archaeological sites - ruins of residential structures, broken pottery, animal bones, and remains of other artefacts, but no people to tell us how they lived, what they ate, which resources they used in their day to day lives, and so on. Enter environmental archaeology! It helps archaeologists understand exactly that! It is ‘the study of people and their relationship with the environment through time’. It provides information about which type of natural resources did people explore and how did they procure these resources for use in their subsistence in the short and the long term, how did they modify the landscapes they lived in, how did they adapt to the changes in weather, climate and how did they cope with natural calamities such as floods or earthquakes. Environmental archaeology also studies how people’s use of the resources in turn must have affected the environment around them. Thus, it is a culture-environment interaction, as I like to put it. 

This interaction between humans and their environments took place over a number of different spatial and temporal scales and still does. Here spatial simply means the geographic range or the scale of area over which a particular process or a combination of processes is occurring, and temporal means the duration of the interactions for e.g. days, months, years, etc. In order to study these different processes, environmental archaeology relies on the natural sciences like biology, chemistry and geology. So yes, it is definitely science-y, but for good reason! If you’re still with me, let’s look at the three major sub-disciplines of environmental archaeology that are used to reconstruct the past environments. These are - zooarchaeology, archaeobotany and geoarchaeology. 

Zooarchaeology is the study of animal remains found at archaeological sites to understand all aspects of past human-animal interactions. Studying faunal evidence from archaeological sites provides insights on the food economy, the age of animals at death, the sex of animals, the techniques employed in hunting, fishing, butchering, cooking and tool making, cultural contacts, social customs, herding and livestock management, animal pathology, the season of occupation of the site, activity areas of the site, available natural resources and also of course the paleoenvironment of the site area. Most of the faunal remains recovered from archaeological sites belong to the vertebrate animals. This is mainly because the bodies of vertebrates are composed of various hard tissues which include bones, teeth, hair, eggshell and other such materials that are more likely to be preserved. In the invertebrate category, only one type is commonly found throughout archaeological sites - shells or molluscs. It is because their outer shells are made of calcium and hence remain well preserved. The hard tissues including bone, teeth, antlers and horn cores are likely to be exceptionally preserved faunal remains as their composition is a mixture of organic and inorganic compounds. 

Besides the macro evidence, the presence of micro fauna on the site can also be studied indirectly through microscopic analyses. For example, in my research on the Early Iron Age habitations in Vidarbha, I found evidence of termites and earthworms as microfauna present at the site. This I discovered by observing the structures that termites build and in the case of earthworms - by the shape and content of their poo! Finding this type of micro evidence is significant as it informs the archaeologist about the taphonomic processes that might have happened in the sediment and the implications it would have in determining the age of the habitation layer, especially if there are dating samples to be extracted from the strata. Taphonomic processes are basically the natural processes that affect factors like preservation or alteration of organic (and inorganic) remains from the time they are buried until the time they are found. 

Archaeobotany is the study of remains of plants cultivated or used by humans in the past which survive in the archaeological contexts. There are macro & micro plant remains. The remains of fruits, seeds, flowers, leaves, stems, wood and roots are all macro remains and have been found in archaeological deposits. Charred plant remains are found at most archaeological sites. Preservation occurs when plant material is burned. This leaves a skeleton of carbon, but sometimes also includes residual starches, lipids and DNA. Microscopic silica remains (phytoliths) of plants are also retrieved from ashy deposits at many sites. The majority of charred macroscopic plant remains are present as a result of anthropogenic activity. In most cases they provide information reflecting the intensity of human activities involving fire. Therefore, scarcity of charred plant remains can, in itself, be useful information. Micro plant remains such as phytoliths and pollen are important environmental records in regions where macro plant remains are not well preserved. Phytoliths are especially important in archaeobotanical studies as these are produced widely, they are more robust and have longer durability in the archaeological record when compared to pollen.

Plant remains are studied to extract information on diet, social aspects of food, arable husbandry practices, foddering of livestock, the introduction of various non-indigenous plants and the reconstruction of local environments, among others. For example, in my doctoral research, I observed that the byproducts of the chiefly cultivated plant at the Early Iron Age site, i.e. rice - husks & leaves - were also used in secondary contexts. Husk was used as fuel source in the hearths and as a tempering material in pottery manufacture, whereas the leaves were mixed with fodder for livestock, and probably also to make floor mats! One crop - so many different purposes! 

The third major sub-discipline in environmental archaeology is geoarchaeology. It is the study of archaeological and geomorphological records combined, to study how humans caused changes in their landscapes. It investigates the nature, sequence and causes of human versus natural impacts on the landscape. It focuses on understanding how deposits were originally formed and subsequently modified through time due to human influence. Geoarchaeological studies also focus on understanding site formation processes, explaining issues of preservation for e.g. Soil condition, taphonomic changes like burrowing caused by earthworms, degradation of organic matter, etc. as well as identifying changes in the physical landscape through time. The processes that played a part in the formation of a deposit are identified by the physical and chemical properties they leave behind, for example - fluvial, colluvial, aeolian, etc. types of processes. Each of these processes are influenced differently by climate, ecology and human activity. 

One geological concept important for reconstructing past environments is uniformitarianism; often phrased as ‘the present is the key to the past’. Introduced in the late eighteenth century, this is the idea that natural processes observed at present have been occurring in the same fundamental ways in the past! Basically it is the idea that natural processes observed today also occurred in the past and produced the same physical effects. For example, we may observe today that a particular species of mollusc (let’s suppose Lymnaea truncatula) inhabits exclusively marshland or wet, muddy areas. If we find shells of that species in an archaeological deposit, we can assume (allowing for taphonomy) that a similar habitat existed nearby at the time the deposit was formed. Uniformitarianism is fundamental to archaeology, because one of the basic assumptions that always needs to be made is that the behaviour and tolerances of plant and animal species were the same in the past as in the present, and hence knowable; and exactly the same applies to early humans—if we could not assume that their physical needs, their tolerances and their behavioural responses were the same in the past, and hence predictable, archaeology would simply be impossible!

What I’ve discussed above is only very basic information and in no way exhaustive explanations of these sub-disciplines. These approaches are used for environmental archaeological investigations by employing a vast range of methods and techniques such as field observations, scientific analyses including but not limited to phytolith, pollen, DNA, isotope, lipids, starch & residue analyses, XRF, radio carbon, XRD, particle size analyses, micromorphological studies - among numerous others! 

To put things in perspective, let’s consider a popular case study - one of my favourite archaeological investigations of all time - of Ötzi, the Iceman! He is a prehistoric mummified human and was found in the Ötztal Alps near the Italian-Austrian border in early 1990s. Since being discovered, the iceman has been a subject to extensive archaeological investigations. His body was exceptionally well preserved because he died in a small rocky hollow which was soon after covered with glacial ice. This glacial ice started melting 5300 years later, which is when his body was discovered! He was identified as a man aged between 35 to 40 years of age when he died. There were several personal artefacts found alongside him, these include an unlined fur robe which was stitched from skins of deer, ibex and chamois, his shoes were made in leather, a fur cap to provide warmth from the cold and a cape made of woven grass. He was also carrying a small copper axe, a flint dagger, several arrows, a net made of grass, a leather pouch and a wooden frame that probably held all these things together as a backpack. 

The mummified body of Ötzi when it was discovered (above) and in the laboratory (below) Credit: https://www.iceman.it/en/the-iceman/

Archaeologists found hophornbeam tree pollen in Ötzi’s body - it flowers in the Alps between the months of March and June and it indicated that he probably died during spring or early summer. A further study of pollen and the isotopic composition of the enamel extracted from his teeth suggested that he spent his childhood somewhere near Bolzano and later settled about a 100 kms further north. Ötzi continues to fascinate the world three decades after his discovery. The mummy offers a glimpse into the life and times of a man who lived over 5,000 years ago. The clothing he wore and the tools he carried suggest he was well adapted to his environment and was well-versed in the plants, and animals of his era. You can read more about the entire reconstruction here in the wikipedia article. Ötzi is now preserved in the South Tyrol Museum of Archaeology in Bolzano.

The reconstruction of Ötzi’s life and death shows us how various environmental remains could tell us so much about his lifetime and therefore, also highlights the importance of studying paleoenvironmental remains found at archaeological sites in order to reconstruct a more holistic picture of the past. 

If you’ve made it this far - bravo! I hope I was able to convey the basics! 

Cheers!

- B.

Here are some more links if you want to read further: 

https://www.pbs.org/wgbh/nova/icemummies/iceman.html 

• Earle, S. (2019). Physical Geology – 2nd Edition. Victoria, B.C.: BC campus.

Retrieved from Physical Geology – 2nd Edition – Open Textbook (Open access available for online reading as well as download)

• Goldberg, P., Macphail, R. I. (2008). Practical and theoretical geoarchaeology.

Oxford: Blackwell publishing.

• Wadia, S., R. Korisettar and V.S. Kale (Eds.) (1995) Quaternary Environments and

Geoarchaeology of India. Essays in honour of Professor S.N. Rajaguru. Memoir No:

32, Geological Society of India, Bangalore.

• Bell, M., Walker, M. J. C. (2014). Late Quaternary Environmental Change: Physical

and Human Perspectives. Routledge.

• Dincauze, D. F. (2000). Environmental archaeology: principles and practice.

Cambridge University Press.

• Heritage, E (2007) Geoarchaeology: Using earth sciences to understand the

archaeological record. English Heritage. 

• Lowe, J. J., Walker, M. J. (1997) Reconstructing Quaternary Environments. London.

• Butzer, K. W. (1982). Archaeology as human ecology: method and theory for a

contextual approach. Cambridge University Press.