30 research outputs found
Ancient DNA Analysis of 8000 B.C. Near Eastern Farmers Supports an Early Neolithic Pioneer Maritime Colonization of Mainland Europe through Cyprus and the Aegean Islands
The genetic impact associated to the Neolithic spread in Europe has been widely debated over the last 20 years. Within this context, ancient DNA studies have provided a more reliable picture by directly analyzing the protagonist populations at different regions in Europe. However, the lack of available data from the original Near Eastern farmers has limited the achieved conclusions, preventing the formulation of continental models of Neolithic expansion. Here we address this issue by presenting mitochondrial DNA data of the original Near-Eastern Neolithic communities with the aim of providing the adequate background for the interpretation of Neolithic genetic data from European samples. Sixty-three skeletons from the Pre Pottery Neolithic B (PPNB) sites of Tell Halula, Tell Ramad and Dja'de El Mughara dating between 8,700–6,600 cal. B.C. were analyzed, and 15 validated mitochondrial DNA profiles were recovered. In order to estimate the demographic contribution of the first farmers to both Central European and Western Mediterranean Neolithic cultures, haplotype and haplogroup diversities in the PPNB sample were compared using phylogeographic and population genetic analyses to available ancient DNA data from human remains belonging to the Linearbandkeramik-Alföldi Vonaldiszes Kerámia and Cardial/Epicardial cultures. We also searched for possible signatures of the original Neolithic expansion over the modern Near Eastern and South European genetic pools, and tried to infer possible routes of expansion by comparing the obtained results to a database of 60 modern populations from both regions. Comparisons performed among the 3 ancient datasets allowed us to identify K and N-derived mitochondrial DNA haplogroups as potential markers of the Neolithic expansion, whose genetic signature would have reached both the Iberian coasts and the Central European plain. Moreover, the observed genetic affinities between the PPNB samples and the modern populations of Cyprus and Crete seem to suggest that the Neolithic was first introduced into Europe through pioneer seafaring colonization
Mitochondrial DNA genetic relationships at the ancient Neolithic site of Tell Halula
The extent of racemization of aspartic acid (Asp) -expressed as D/L ratio- has been used as a marker of biomolecular degradation in ancient remains. However, Asp racemization rate is highly variable, and depends on biochemical and geochemical factors. In this paper we aim to determine to which extent the fraction analyzed and the kind of sample used may influence the D/L Asp ratios. Other factors, such as burial site and sample preservation conditions, are also considered. D/L Asp ratios were obtained in 38 ancient human samples from 30 different individuals in which Real Time PCR quantification and amplification of short mtDNA fragments had been previously achieved. Four samples were taken from bones, 16 from whole teeth and 18 from dentine. In 7 cases whole tooth and dentine fractions from the same individual were analyzed. The samples belonged to 8 archaeological sites from Pre-pottery Neolithic B (PPNB), Cardial Neolithic and Chalcolithic time periods. Results show significant differences between the D/L Asp ratios obtained in dentine and whole tooth fractions from the same tooth and individual, as well as among dentine samples from the same archaeological site and among samples of the same age from different, though nearby, archaeological sites. Ancient DNA (aDNA) could be characterized in the majority of the samples, independently from their racemization values, which suggests that other factors, apart from the sample preservation stage, are more significantly affecting the racemization rate. A generalized use of the Asp racemization ratio as a threshold value for ancient DNA preservation needs to be questioned until further methodological standardization is considered
The distinctive character of human being in evolution
Human beings, as we know and understand them today, are the result of a lengthy, two million year old process that has made them one of the most powerful and beautiful biological beings. The process of encephalisation in humans, combined with the development of areas of speech, brought about by a neurological reorganisa-tion that may have taken place before the increase in brain size, has enabled humanity to generate a tremendous cognitive capacity that in turn has led to the development of what we know of as culture. Culture influences biological development. No other species has achieved the like anywhere. For human survival, culture is a new dimension, a new habitat, which humanity has to adapt as it creates it. Culture is not written into the genome, but it can be transmitted and communicated thanks to speech. This enables knowledge to be shared and transmitted to other members of the group or society, to communicate ideas, concepts and abstractions. Knowledge enables a society to form a structure and make it more complex than a simple agglomeration of individuals while also creating an environment where raising children is viable since it can guarantee their survival, giving them the right treatment to enable them to reach adulthood. It has been said that ‘humanity is a spirit in time’, hence the need to understand the essence of human natural history; the importance of paying it sufficient attention to ensure that what is attractive about its history does not become indigestible
The distinctive character of human being in evolution
Human beings, as we know and understand them today, are the result of a lengthy, two million year old process that has made them one of the most powerful and beautiful biological beings. The process of encephalisation in humans, combined with the development of areas of speech, brought about by a neurological reorganisa-tion that may have taken place before the increase in brain size, has enabled humanity to generate a tremendous cognitive capacity that in turn has led to the development of what we know of as culture. Culture influences biological development. No other species has achieved the like anywhere. For human survival, culture is a new dimension, a new habitat, which humanity has to adapt as it creates it. Culture is not written into the genome, but it can be transmitted and communicated thanks to speech. This enables knowledge to be shared and transmitted to other members of the group or society, to communicate ideas, concepts and abstractions. Knowledge enables a society to form a structure and make it more complex than a simple agglomeration of individuals while also creating an environment where raising children is viable since it can guarantee their survival, giving them the right treatment to enable them to reach adulthood. It has been said that ‘humanity is a spirit in time’, hence the need to understand the essence of human natural history; the importance of paying it sufficient attention to ensure that what is attractive about its history does not become indigestible