Neanderthals, which were archaic humans who emerged about 200,000 years ago, mostly lived in caves, and led a hunter-gatherer lifestyle. Now, a team of researchers led by the University of Southampton has found interesting details about what Neanderthals and ancient humans living in western Europe ate and hunted.
They studied the chemical properties of the enamel of Neanderthal and animal teeth found from the Almonda Cave system in Portugal. The findings unravel mysteries of how prehistoric humans lived in the land around the Almonda Cave system about 100,000 years ago.
The study describing the results was recently published in the journal PNAS.
According to the study authors, understanding mobility and landscape use may help researchers understand phenomena such as the biological and cultural interactions between distinct populations of Upper Pleistocene humans, who lived 0.126 million to 0.012 million years ago.
What did Neanderthals and ancient humans hunt?
After analysing the tooth, the researchers found that Neanderthals living around the Almonda Cave system likely hunted fairly large animals across wide tracts of land. Meanwhile, humans who lived in the same location tens of thousands of years later consumed smaller creatures in an area half the size.
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Using laser sampling to analyse strontium isotopes
Radioactive processes gradually change strontium isotopes in rocks, over millions of years. Therefore, different places have varying levels of strontium isotopes, depending on the age of the underlying geology.
Weathering of rocks creates sediments, which contain isotopic fingerprints. When plants grow in the soil containing these sediments, the fingerprints are passed on to the plants.
After this, the isotopic fingerprints go further up the food chain, and eventually reach one's tooth enamel.
As part of the study, archaeologists laser-sampled enamel and made thousands of individual strontium isotope measurements along the growth of a tooth crown, a statement released by the University of Southampton said.
Who did the tooth enamel samples belong to?
Some of the tooth enamel samples belonged to two Neanderthals who lived about 95,000 years ago, while other samples belonged to a more recent human who lived about 13,000 years ago, during the Magdalenian period, which occurred from 23,000 to 14,000 years ago.
Analysing teeth belonging to animals
The researchers also found teeth belonging to animals in the cave system. They analysed the isotopes in the enamel of these samples, and measured strontium as well as oxygen isotopes.
According to the study, oxygen isotopes vary seasonally from summer to winter. Using this knowledge, the researchers were able to establish where the animals travelled across the landscape, and in which seasons they were available for hunting.
What the Neanderthals and ancient humans ate
The Neanderthals hunted large animals. They probably hunted wild goats in the summer, and horses, red deer, and an extinct form of rhinoceros all year around. This is because horses, red deer and rhinoceros were available the entire year within a radius of about 30 kilometres around the cave.
However, the lifestyle of the Magdalenian individual was different. The findings suggest that the person showed seasonal movement of about 20 kilometres from the Almonda caves to the banks of the Tagus River, and consumed a diet which included red deer, freshwater fish, rabbits and wild goats.
Areas of the territories of the Neanderthals and Magdelenian groups
Upon approximating the territory of these two different human groups, the researchers found that the Neanderthals gathered their food within an area extending up to 600 square kilometres from where they lived. Meanwhile, the Magdalenian individuals lived in a much smaller territory which had an area of about 300 square kilometres.
In the statement, Dr Bethan Linscott, the lead author on the paper, said since tooth enamel forms incrementally, or grows regularly in stages, it represents a time series that records the geological origin of the food an individual ate.
Linscott explained that the researchers measured the variation of strontium isotopes over the two or three years it takes for the enamel to form, with the help of laser ablation. Then, they compared the strontium isotopes in the teeth with sediments collected at different locations around the Almonda Cave system. This helped them map the movements of the Neanderthals and the Magdalenian individual.
Linscott said that the geology around the Almonda Cave system is highly variable, and hence, it was possible to spot the movement within just a few kilometres.
Why were the territory sizes different?
Quoting co-author João Zilhão, the statement said the difference in the territory size between the Neanderthal and Magdalenian individuals is probably related to the population density.
Zilhão explained that Neanderthals had a relatively low population, and were able to freely roam further to target large prey species such as horses, without encountering rival groups.
Meanwhile, there was an increase in population density by the Magdalenian Period, which reduced available territory. As a result, human groups moved down the food chain to occupy smaller territories, and hunted mostly rabbits and caught fish on a seasonal basis.
The authors concluded that the Middle Paleolithic (2,50,000 to 30,000 years ago) individuals roamed across a territory of approximately 600 square kilometres for survival, while the Late Magdalenian individual showed seasonal movement along the right bank of the 20-kilometre-long Almonda River valley. The individual exploited a smaller territory of approximately 300 square kilometres.