martes, 28 de enero de 2014

Scientists collaborated on a study on the origins of the domestic dog


The geographic and temporary origins of the canids’ domestication have aroused controversy in the scientific field. Although there are hypotheses that support the fact that this process initiated 15.000 years ago in the east of Asia, the results of a recent study – where Argentine researchers participated – indicate that the process would have started in Europe between 18.800 and 32.100 years ago.
The study was published in the academic journal Science on November 15th and it compares DNA sequences of 18 prehistoric canids and 20 modern wolves, the genomes of 49 wolves and 77 modern canids.
Daniel Loponte and Alejandro Acosta, CONICET assistant researchers at the National Institute of Anthropology and Latin American Thinking (INAPL, UBA-CONICET) were invited to participate for their studies on domestic dogs in Argentina and South America.
“In 2005, in an archaeological site located at the Paraná Delta, we retrieved a complete skeleton of a prehispanic dog in an excellent state of preservation. It was one of the most complete specimens found in Argentina so far. This specimen was interesting so as to link it with the ones sent from other parts of the world. A team of geneticists coordinated by the Finnish scientist Olaf Thalmann analysed the mitochondrial DNA and we discussed the results”. Loponte affirms.
The conclusions of the study indicate that the domestication of the dog is the result of a process initiated by hunter-gatherers of the Upper Paleolithic. There is evidence of what could be failed attempts of domestication of Belgian species 30.000 years ago.
The researchers explain that the grey wolf is the direct predecessor of the dog but after its domestication the morphological variation rate occurred at a high pace and probably progressive in time, a phenomena that has not been observed in other species. “There is a great phenotypic difference between a Basenji, a Chongquing and a poodle”, Loponte illustrates. Nowadays, this morphotypical variation is distributed in 340 subspecies of dogs recognized by the Fédération Cynologique Internationale.
The study explains the domestication started during the last glaciation, approximately 20.000 years ago. The hunter-gatherers started to relate to dogs in an era where humans hunted big animals.
For the researcher, it is possible that the association was not intentional but part of a long coevolutionary process that led to a mutualism than benefited both species: humans and canids.
“Probably, men gained advantages for prey capture, defense of killing sites against great natural competitors and detection of dangers in camps. In turn, dogs incorporated multiple benefits as food that humans discarded or were not able to process, as well as reproductive security”, Loponte concludes.
Source: DiCYT:

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