New Delhi: An international team of researchers have found that the shift from primarily hunting, gathering, and foraging to farming about 12,000 years ago in Europe may have had negative health effects on individuals. These include shorter than expected heights in earliest farmers.
The study, led by researchers at Pennsylvania State University, United States, was recently published in the journal Proceedings of the National Academy of Sciences.
Individuals From Copper, Bronze, Iron Ages Studied
The team looked at the heights of individuals who lived before the Neolithic, and in the Neolithic, Copper, Bronze and Iron Ages. The team also measured the long bones of skeletal remains that were being sampled or already been sampled for ancient DNA testing by other researchers.
In a statement issued by Pennsylvania State University, Stephanie Marciniak, the lead author of the study, said that recent studies tried to characterise the contribution of DNA to height, and that the team started thinking about the long-standing questions around the shift from hunting, gathering, and foraging to sedentary farming, and decided to look at the health effect with height as proxy.
Building a model that used adult height, indicators of stress seen in the bones and ancient DNA, the researchers looked at genetic indications of ancestry.
Marciniak said their approach is unique in that they used height measurements and ancient DNA taken from the same individuals.
According to the study, the switch from a hunting, gathering, and foraging lifestyle to an agricultural lifestyle did not occur across Europe simultaneously, but in different places at different times.
Findings Of The Study
As many as 167 individuals who lived from 38,000 to 2,400 years ago were studied. These individuals included pre-agricultural individuals, the earliest farmers, and subsequent farmers.
The researchers found that individuals from the Neolithic were an average of 1.5 inches shorter than previous individuals, and 0.87 inches shorter than subsequent individuals. The team had taken into account the genetically indicated potential heights of the individuals from the Neolithic.
The researchers also found that the heights of individuals increased through the Copper Age, by 0.77 inches, through the Bronze Age, by 1.06 inches, and through the Iron Age, by 1.29 inches, with respect to Neolithic heights.
Marciniak said that right now, the team knows that 80 per cent of height is from genetic makeup and 20 per cent is from the environment. She said researchers have not yet identified all the genetic variants associated with height.
According to Marciniak, the switch from hunting, gathering, and foraging to agriculture did not always result in a height loss, although it did in some parts of Europe.
She said there was movement of people, generally from east to west. The researchers wanted to account for that migration that perhaps brought different proportions of height-associated genetic variants, she added.
The researchers incorporated ancestral information and found that for the Neolithic, the height decrease is reduced a bit so that it is not as extreme.
According to the researchers, their approach is adaptable to studies of past human health and could be applied in other areas.