How technology helped archaeologists to dig deeper in ancient cities
Joseph Jones, a sociologist at William & Mary College and one of the researchers at the site, told me that science has matured even though his team is still researching. Early in their excavations, they analyzed fossils using methods that archaeologists have used for nearly a century, measuring bone growth and detecting damage to them in order to find out more about human life. Today, however, the team is using it modern methods that previous generations of researchers simply wished they had used lasers to cut small enamel pieces so that the isotops locked inside could be analyzed; classifying old DNA to connect people who died hundreds of years ago with their descendants.
The African Burial Ground was unveiled during a cultural discovery. Historians were exploring the role of slaves in the construction of northern cities, while black scholars such as Henry Louis Gates Jr. and writers like Toni Morrison were African-American historians in US history.
Scientific research at the site increased awareness of these groups and changed the way most Americans view the establishment of their country. It revealed that African slaves had built many of the cities where Americans still live – North and South. And it showed how we have evolved into nomadic species that migrate in small groups to share a strong habitat with millions of other people.
The African Burial Ground project was one of the first to use a new group of “bioarchaeology” tools that surpassed traditional pickaxes and brushes. But this was the first phase of an archaeological revolution that brought scientists and human scientists to the forefront of our knowledge about our ancestors. Nowadays, researchers support bioarcheology with 3D photography, lidar, satellite imagery, and more.
Sometimes referred to as “archaeological research,” this type of research is well worth studying the history of cities. Using remote technologies like lidar, researchers can access the entire city grid, giving us a good idea of what it would be like to walk around and take a look at the shops. This type of data makes digital editing more accurate, which means that historians can turn a remote, inaccessible page into something that anyone can access online.
This also reflects history, as well: scholars can now analyze hundreds, if not thousands, of data, and analyze a wide range of data to understand the plight of ordinary people – not just a few who had the opportunity to own a place, sign names, or government officials.
Explaining the tooth
Archaeological excavations are especially useful for historians who study the cities because urban areas often contain stories of visitors that may be difficult to find. Michael Blakey, a researcher who led the project at the Africa Burial Ground since the early 1990’s, said his team would not know where cemeteries come from if they did not know several types of chemical analysis on their dental enamel. Because this enamel is formed in areas where people grow up, scientists are able to study the part of the tooth and discover things that people have seen in childhood. It is like examining tree rings, whereas each enamel represents a person’s lifetime.
At the same time, he discovered the distinctive line between African-born and American-born: lead. Although African development worked with a number of metals, lead was only used by Europeans, for things like pipes and pewter plates. Anyone who had lead in childhood dental enamel was almost a native.
With the advent of science, the Blakey team also used a method called strontium isotope analysis to find out more about human origins. When people eat and drink in a certain area for a long time, their teeth take up a little strontium, something that comes out from under the rocks into food and drinking water. Older Strontium has a distinct signature that differs from strontium from new ones, so looking at an isotope in human enamel lets researchers know where they live for the rest of their lives.