A recent study led by the Pennsylvania State University has made a surprising discovery: the switch from hunting, gathering, and foraging to farming approximately 12,000 years ago in Europe may have had negative health effects on our ancestors, as indicated by shorter than expected heights in the earlier farmer populations. This might have been caused by poorer and less diverse diets and the prevalence of infectious diseases among denser populations.
“Recent studies tried to characterize the contribution of DNA to height,” said study lead author Stephanie Marciniak, an assistant professor of Anthropology at Penn State. “We started thinking about the longstanding questions around the shift from hunting, gathering, and foraging to sedentary farming and decided to look at the health effect with height as a proxy. Our approach is unique in that we used height measurements and ancient DNA taken from the same individuals.”
Professor Marciniak and her colleagues studied the skeletal remains of 167 individuals who lived from 38,000 to 2,400 years ago, thus spanning the Neolithic, Copper, Bronze, and Iron ages. By employing a new model that took into account adult height, indicators of stress observed in the bones, and ancient DNA, the scientists have found that individuals from the Neolithic period – when farming emerged as a widespread practice – were an average of 1.5 inches shorter than previous individuals and 0.87 inches shorter than subsequent ones. Moreover, heights seemed to steadily increase through the Copper, Bronze, and Iron ages in comparison to the Neolithic average (by 0.77, 1.06, and 1.29 inches, respectively).
However, when researchers took into account the variations in genetic ancestry influenced by patterns of Neolithic migrations, they found that the switch from hunting and gathering to agriculture did not always result in height loss, although the height drop around the beginning of farming was still evident.
“There was movement of people, generally from east to west,” Professor Marciniak said. “We wanted to account for that migration that perhaps brought different proportions of height-associated genetic variants.”
“This research requires more study with larger datasets. Our work represents a snapshot of something that is very dynamic and very nuanced. We need to do more to see what is the cause of the decrease in achieved height versus predicted genetic height during the shift to farming,” she concluded.
The study is published in the journal Proceedings of the National Academy of Sciences.
By Andrei Ionescu, Earth.com Staff Writer