Two studies of fossil teeth point to deep Neanderthal roots in Europe
Two studies of fossil teeth point to deep Neanderthal roots in Europe
Two studies of fossil teeth point to deep Neanderthal roots in Europe
An international team of researchers has published today in the magazine 'PLOS One' separate studies of fossil teeth that provide, independently, strong evidence in favor of the deep roots of Neanderthals in Europe. In one of them it has been discovered that, about one million years ago, 'Homo antecessor' presents a series of characteristics regarding the distribution of dental tissues that are considered typical of Neandertals. The second work endorses that, around 450,000 years, there is a fully Neanderthal dentition both in the distribution of tissues and morphology, which would ratify the idea that the Neandertals are a lineage of ancient origin that was separated from the genealogy sapiens well before half a million years.
This is explained to DiCYT María Martinón Torres, director of the National Research Center on Human Evolution (CENIEH) (Spain) and co-author of both studies, who details that, so far, the population of the hominids of Sima de los Huesos (Atapuerca), about 430,000 years old, represented the oldest population with clearly Neanderthal features. Some members of the scientific community found this surprising finding, because they thought that the Sima de los Huesos was "too old" to present such Neanderthal traits.
Now, the study of a set of seven teeth found in two Italian sites contemporary with Sima de los Huesos (Fontana Ranuccio -in the center of Italy- and Visogliano -in the northeast of the country-), confirms that the strictly Neanderthal characteristics of Teething is at least 450,000 years old.
Enamel thickness of 'H. antecessor 'of Gran Dolina (Atapuerca) compared to Neanderthal and modern human. (Photo: Martín-Francés et al., 2018)
The team, led by Clément Zanolli, of the Toulouse III University Paul Sabatier (France), has used computerized microtomography (microCT), a technique based on X-rays that allows the visualization, reconstruction and 2D and 3D analysis of the internal structures of the tooth, such as the pulp cavity or dentin, the tissue that is below the enamel. It is a non-destructive method that provides researchers with additional information, for example, on the variations in the shape and thickness of the tissues of the teeth and how they are distributed, and they are useful to determine to which species a fossil belonged ( taxonomy) and what is its relationship with other hominins (phylogeny).
"Both in the form and in the distribution of dental tissues, these teeth present typical characteristics of the Neandertals and other populations of the Middle Pleistocene, such as that of the Sima de los Huesos, and they are clearly different from modern humans", underlines Martinón Torres, who adds that this indicates that the separation between the Neanderthal lineage and that of modern humans "had to be necessarily prior to the antiquity of these sites".
But not all populations in this chronology have the same degree of similarity with Neandertals, the researchers warn. The analysis of the hominins found in Arago (France), with an antiquity similar to that of Sima de los Huesos, Fontana Ranuccio and Visogliano, reveals that their dentition was more primitive. And other populations of similar chronologies, such as Ceprano (Italy) or Mala Balanica (Serbia) do not present any Neanderthal trait. "All this points to the possibility that during the Middle Pleistocene, Europe was inhabited by at least two different genealogies, one that is related to the Neandertals, and another more primitive, perhaps a late survivor of the first inhabitants of Europe," suggests the director of CENIEH.
The second work, whose first author is Laura Martín Francés, from the University of Bordeaux (France), analyzes the thickness and distribution of the dental tissues of the molars of the species 'Homo antecessor', found in the site of Gran Dolina ( Atapuerca). At about 860,000 years of age, this collection represents the oldest inhabitants of the European continent and was proposed in 1997 as the best candidate for the last common ancestor of modern humans and Neanderthals.
The study concludes that 'Homo antecessor' presents primitive characteristics, in line with its antiquity, as well as a relatively thick tooth enamel, like most hominins except Neandertals. However, and it is the main finding of the work, "in some features related to the way in which the enamel is distributed in the crown, 'H. antecessor 'presents traits that are considered typical and exclusive to Neandertals, "which shows that some of the typical Neanderthal characteristics" originated nearly a million years ago, "Martinón Torres points out. (Source: CGP / DICYT)
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