We know that illnesses have existed as long as there have been humans to get ill – but how do archaeologists identify disease in the past?
Palaeopathology is the study of ancient diseases, which archaeologists can identify by examining both hard skeletal and soft tissue remains. Understanding the types of illnesses that ancient people dealt with provides a lot of information about how life was in the past, but can also help us understand the diseases of today.
1. Soft tissue remains
Mummies have a lot to offer when it comes to evidence of disease because there is so much soft tissue preservation.
CT scans of 137 mummies from different populations found that more than 30% of them suffered –had clogged arteries (artherosclerosis). Until now, clogged arteries were thought to be a modern affliction, down to fatty foods and lazy lifestyles. Apparently ancient people needed to cut down on the crisps too!
2. Skeletal remains
There are plenty of diseases that leave tell-tale signs on the skeleton, including joint diseases, infectious diseases, trauma, oral diseases and tumours.
Take syphilis, an infectious disease that leaves very distinctive lesions on bones including the skull, shin and tibia. Archaeologists have now traced its origins to the New World, where it mutated from an older disease called yaws around 1600 years ago.
3. Chemical analysis
Chemical analysis can tell us a lot about disease in the past. Researchers have recently developed a way to diagnose malaria in archaeological bones. using Roman skeletons from 550 AD.
4. Molecular analysis
Molecular analysis is exactly what the name suggests – the analysis of molecules, including DNA, in ancient remains that may suggest disease.
Researchers have been arguing about whether Europeans brought Tuberculosis to the New World, but German scientists recently showed that it existed in the New World before contact by Colombus. By finding and extracting tuberculosis DNA from Peruvian skeletons and comparing it to modern strains they were surprised to find the closest variant was actually the type found in seals – meaning that TB-infected animals were responsible for the spread of the disease.
5. Histological analysis
Histology is the study of cellular structures in palaeopathology this often means looking at skeletal remains with microscopes to examine cellular abnormalities caused by disease.
Histology was used to disprove the theory that ‘Dr Granville’s mummy’ – a famous specimen from Egypt autopsied in 1825 – had died from an ovarian cyst. Modern researchers examined the cyst and concluded it was benign. Further study revealed abnormal lung cells which lead to the diagnosis of tuberculosis as the true cause of death.
6. Radiographic Analysis
Radiography – using electromagnetic radiation (like x-rays) to create images of the internal structure of the body or bones is a common technique used when looking for disease.
Radiography was used in combination with other palaeopathological methods to identify early evidence of cancer in a 3000 year old skeleton from Sudan. researchers examined bone lesions on the skeleton and determined they were a symptom of an unknown soft tissue cancer. The scientists noted that radiography is one of the best ways to see inside the bones into where the disease begins and make observations not visible to the naked eye.
And finally… Why do we study disease?
Palaeopathology tells us about the types of diseases that ancient people were dealing with which can provide information about quality of life as well as medical care, diet and nutrition. It can also illustrate how past cultures may have interacted by examining the way that a particular disease evolves and spreads. This information is useful for the understanding of the past but can also provide insight into modern disease and help scientists to predict how disease may act in the present. Disease has been a part of human life as long as there have been people to get sick, this makes it an incredibly important field of study when it comes to understanding past lives.
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