Archaeologists use the following steps to determine how many people may have lived at a site:
- First, count or estimate the number of rooms at a site.
- Next, decide how many rooms were in use at the same time. Some rooms were likely associated with the founding of the site, some with the middle occupation, and some were only used near the end of the occupation. Remember the Piece of the Puzzle that focused on using pottery to date things? Pottery can help archaeologists determine which rooms were lived in first, and which last.
- Finally, use trends among historic American Indians to arrive at a reasonable estimate of the number of people who lived in each room.
Tracking Population Changes through Time and across Geographic Place
Regional population trends can be examined by comparing data for all of the sites in an area over different periods of time. Population estimates and other information can be collected in a database, and then examined from different perspectives. What was previously a long, laborious, and error-filled process has been simplified and streamlined, thanks to advances in computing technology.
For this project, information on the location, date, and size of archaeological sites in the Southwest occupied between A.D. 1200 and 1700 was compiled into a Geographic Information System (GIS) called the Coalescent Communities Database. This database now includes information about more than 4,000 sites. It is a powerful tool in the quest to analyze and illustrate population changes in the ancient Southwest.
How Did Ancient Population Levels Change in the Southwest?
The latest research indicates that more than 40,000 people lived in the Hohokam region around A.D. 1300. Fewer than 10,000 were living in the same area by the mid-1400s. Remember the Puzzle Piece that focused on evidence for migration? Unexpectedly, this population decline took place during a period when the region was experiencing an influx of immigrants.
- Archaeologists estimate site population by counting rooms, figuring out how many rooms were occupied during different periods of time, and estimating the number of people per room based on trends among historic American Indians.
- Advances in computer technology, especially the use of Geographic Information Systems, have given archaeologists much more effective ways to investigate and illustrate changes in population through time at the scale of the entire Southwest.
- The Hohokam region was gradually depopulated despite an influx of immigrants from northern Arizona.
- The Four Corners region was rapidly depopulated during the late 1200s.
- Throughout the Southwest, people were living in fewer but larger sites, leaving more space between clusters of sites.
- The Hohokam region was gradually depopulated.