17:55 December 21, 2021
CC BY 3.0 / /
In an interesting study, Serbian and foreign scientists used the method of annulment of tartar on the
teeth of individuals from the Mesolithic and Neolithic periods to examine physiological stress before and during the Neolithic demographic transition in Europe. What did they learn from that? And why does this matter?
Abrogation dental cement (
Tooth cementum annulation ) the microscopic method, which is mainly used for determining the age of the individual. The results obtained by applying this method are closest to the actual (chronological) age of the individual.
Scientists cut the remains of the teeth with a diamond saw, make a small section and look at the plate under a microscope. Here they can see the so-called lines of annulment, because
every year the tooth gets one layer of dental cement . It is the same as with rings on a tree. Counting those lines, we can say how old someone was at the time of death. This method is also used in forensics and is very accurate.
However,
by observing these lines on the teeth, scientists can also see the physiological stress that occurred during a certain period of a woman's or man's life. Physiologically demanding events such as pregnancy and lactation are known to have multiple effects on the skeleton, such as significantly altered bone metabolic status.
The study used the method of dental cement annihilation (TCA) to examine physiological stress before and during the Neolithic demographic transition in Europe. Episodes of physiological stress are reflected as "stress lines" in tooth cementum at almost annual resolution.
The TCA method was used to detect and count stress events for a sample of 21 Mesolithic and 25 Neolithic individuals from the central Balkans between 9,500 and 5,400 BC. In line with the theory of Neolithic demographic transition, scientists assume that Neolithic individuals will have more stress than Mesolithic individuals.
The results suggest that Neolithic women had significantly more stress lines in tooth cementum per year than Mesolithic women. The difference between Mesolithic and Neolithic men was not statistically significant.
The conclusion is that
Neolithic women had more episodes of physiological stress than Mesolithic women. The differential pattern between the sexes, combined with the fact that pregnancies are one of the main causes of the formation of stress lines in tooth cementum, may indicate that the observed differences are mainly due to increased fertility in the Neolithic.
Why is the Neolithic demographic transition important?
At the time of the beginning of the Mesolithic, there are
climate changes - the retreat of glaciers, an increase in the lushness of vegetation, new species - the previous living conditions are changing. The Mesolithic is known as the Older, and the Neolithic as the Younger Stone Age within prehistory. With the Neolithic comes the aforementioned demographic expansion - scientists believe that more children are born then than before.
The first demographic transition in human (pre) history occurred in the Neolithic period when the global size of the population increased dramatically. This is a period of change from the way of life of hunters-gatherers-fishermen to food production, animal husbandry and animal husbandry that took place in the early Holocene and represents the transition from the Mesolithic to the Neolithic period in Europe. It is assumed that the
flourishing of the Neolithic population was caused by the increase in women's fertility due to a
sedentary lifestyle and the availability of high-calorie food.
Support for this hypothesis comes from the observed increase in the share of subadult individuals (child skeletons and burials) in Neolithic prehistory around the world as an indirect measure of fertility. It is also assumed that increased population size and density, combined with new lifestyles (changes in diet, increased labor demands, sedentary lifestyle, proximity to domestic animals and poor hygiene conditions increase the likelihood of various infections) have resulted in an
overall decline in health .
Together, the increase in fertility and the decline in health that resulted in increased mortality are the two main processes that define and structure the Neolithic demographic transition. Both increased fertility and increased mortality should be reflected in bioarchaeological records as an increase in various types of biological stress. However, so far there has been no direct or independent evidence.
What did the scientists and collaborators conclude in their work?
"Our results support the hypothesis of increased physiological stress in the population of prehistoric farmers. The differential pattern between the sexes can be conditionally interpreted as evidence for the increase in female fertility in the Neolithic period - that the increase in the number of births was the main (but not the only) contribution to increasing stress during the Neolithic transition, "said Kristina Penezic. her associates.
If this interpretation is correct, the research states, the results would provide direct empirical evidence in favor of the general theory of demographic transition in agriculture, where increasing fertility is assumed to be the main driver of population expansion in agriculture.
"The method we used has a wide bioarchaeological potential, because it allows researchers to gain a more direct insight into physiological stress in past populations. Perhaps the greatest potential methods of researching series paleodemografskih and social issues that include birth and motherhood, but this time interpretation requires further methodological research to formulate criteria for distinguishing pregnancy from other causes of stress, "the statement of reasons,
transfers National Geography.
