Public release date: 23-Jun-2010
Separation between Neanderthal and Homo sapiens might have occurred 500,000 years earlier
The separation of Neanderthal and Homo sapiens might have occurred at least one million years ago, more than 500.000 years earlier than previously believed after DNA-based analyses. A doctoral thesis conducted at the National Center for Research on Human Evolution (Centro Nacional de Investigación sobre la Evolución Humana) -associated with the University of Granada-, analysed the teeth of almost all species of hominids that have existed during the past 4 million years. Quantitative methods were employed and they managed to identify Neanderthal features in ancient European populations.
The main purpose of this research –whose author is Aida Gómez Robles- was to reconstruct the history of evolution of Human species using the information provided by the teeth, which are the most numerous and best preserved remains of the fossil record. To this purpose, a large sample of dental fossils from different sites in Africa, Asia and Europe was analysed. The morphological differences of each dental class was assessed and the ability of each tooth to identify the species to which its owner belonged was analysed.
The researcher concluded that it is possible to correctly determine the species to which an isolated tooth belonged with a success rate ranging from 60% to 80%. Although these values are not very high, they increase as different dental classes from the same individual are added. That means that if several teeth from the same individual are analysed, the probability of correctly identifying the species can reach 100%.
Aida Gómez Robles explains that, from all the species of hominids currently known "none of them has a probability higher than 5% to be the common ancestor of Neardenthals and Homo sapiens. Therefore, the common ancestor of this lineage is likely to have not been discovered yet". http://www.eurekalert.org/pub_releases/ ... 062310.php