Peoples of the Mesa Verde Region
Estimating Population Growth
How do archaeologists know that the population grew during the Basketmaker III period, and why do they think the increase was due mainly to immigration?
Most often archaeologists measure population size by counting the places—usually sites or structures—where people lived. That may sound simple, but it's not. How can you be sure that you have found all the places where people lived, and how do you know which of those places were lived in at the same time? Archaeologists conduct surveys to try to find all the sites in a given area, and they use various dating techniques to estimate when those sites were built and occupied.
In the case of the Basketmaker II and Basketmaker III periods, we also need to keep in mind that they lasted for different lengths of time. The Basketmaker II period lasted for 1,000 years; the Basketmaker III period, for only 250. Yet, archaeologists have found far more Basketmaker III sites than Basketmaker II sites in the Mesa Verde region. That's pretty convincing evidence that the size of the population increased dramatically during the Basketmaker III period!
So why do archaeologists think that the population boom was primarily the result of immigration into the area? Because the increase in population was so large and so rapid that it is unlikely that natural growth—that is, the natural birth rate—could account for it.
Much more research is needed for us to better understand exactly where the Basketmaker III immigrants came from and why, what kinds of communities they lived in, and the impact they had on the almost-pristine landscape they found as they entered the central Mesa Verde region. That's why Crow Canyon's current excavation project is focused on a large Basketmaker III community located not far from campus. Read all about it!
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