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Coins Reveal Clues About Ancient Roman Population

October 07, 2009 02:15 PM
by Anita Gutierrez-Folch
Based on the discovery of ancient coin hoards, two scientists believe the population of ancient Rome may have been smaller than previously suggested, an issue that is widely debated.

Coin Hoards Reveal Population Decline

Using a mathematical model that “predict[s] population trends based on ancient coin hoards,” biologist Peter Turchin from the University of Connecticut and historian Walter Scheidel from Stanford University have suggested that the population of ancient Rome during the first century BC may have been smaller than initially thought, ScienceDaily reports. 

In an article published in the Proceedings of the National Academy of Sciences (PNAS), Turchin and Scheidel explain that the actual size of the population in ancient Rome is dependent on whether early Imperial censuses considered just adult males or included women and children in their count. This fact would determine if “the Roman citizen population of Italy either declined, or more than doubled, during the first century BCE,” the article states.

If the “high count” hypothesis proved to be true, suggesting a boom in the population of the Roman Empire, “much of Roman history as it currently stands would have to be re-written,” and “the popular view of the economic scope and social structure of ancient Rome” would have to be reconsidered, ScienceDaily notes.

In an attempt to clear this debate, the two academics looked at the ancient coin hoards typically buried by citizens “during times of great violence and political strife,” reasoning that the coins could provide an “indicator of population demographics.” Scheidel and Turchin then applied a mathematical model “to project population dynamics before and after 100 BC,” ScienceDaily explains. “Hoards are an excellent indicator of internal turmoil,” Turchin told ScienceDaily. “[L]ittle catastrophes happening to small people, in accumulation, can give us a very good idea of what happened at the macro-level to the whole society.”

Consistent with the association between “high levels of sociopolitical instability” and “demographic contractions,” described in PNAS, their mathematical model predicted a decline in population after 100 BC, suggesting that the “vigorous population growth scenario of the ‘high count’ is highly implausible,” ScienceDaily reports.

In a statement quoted by Discovery News, Turchin explains that it would be “very difficult to imagine how a population could grow during a period of such violence, and the model provides a precise quantitative statement of this.”

Background: Collaborations between science and the humanities

The work of Turchin and Scheidel is an excellent example of a collaborative approach to the study of ancient civilization that combines mathematical modeling and data analysis, thus “compensat[ing] for the scarcity of reliable statistics from pre-modern societies,” ScienceDaily quotes Turchin as saying.

Turchin calls such collaborations “cliodynamics,” an approach to the study of ancient civilizations that proposes “a systematic application of the scientific method to history.” This approach tests empirical material using mathematical models and precise, analytical predictions, aiming to ultimately “discover general principles that explain the functioning and dynamics of actual historical societies.” On his Web site dedicated to the approach, Turchin explains the development of this science and its use by scientists and humanists around the world.

Related Topic: Italy’s population expected to drop 22 percent

During the 1970s, Italian men averaged 71 million spermatozoa per millimeter. But today, they average 60 million, according to a study of 10,000 healthy men conducted by Fabrizio Menchini Fabris of Pisa University. As a result, Italy's population is expected to drop 22 percent by 2050.

Geography and environmental factors figured largely in the study. Men who reside in bigger cities or agricultural locations where the use of pesticides is common had 20 percent less mobile sperm than smaller town and village dwellers, and sperm that were 15 percent more defective.

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