DNA traces cattle back to a small herd domesticated around 10,500 years ago
31 March 2012
All cattle are descended from as few as 80 animals that were domesticated from wild ox in the Near East some 10,500 years ago, according to a new genetic study.
An international team of scientists from the Le Centre national de la recherche scientifique (CNRS) and National Museum of Natural History in France, the University of Mainz in Germany, and UCL in the UK were able to conduct the study by first extracting DNA from the bones of domestic cattle excavated in Iranian archaeological sites.
These sites date to not long after the invention of farming and are in the region where cattle were first domesticated.
The team examined how small differences in the DNA sequences of those ancient cattle, as well as cattle living today, could have arisen given different population histories. Using computer simulations they found that the DNA differences could only have arisen if a small number of animals, approximately 80, were domesticated from wild ox (aurochs).
The study has been published in the current issue of the journal Molecular Biology and Evolution.
Dr Ruth Bollongino of CNRS, France, and the University of Mainz, Germany; lead author of the study, says, ''Getting reliable DNA sequences from remains found in cold environments is routine. That is why mammoths were one of the first extinct species to have their DNA read. But getting reliable DNA from bones found in hot regions is much more difficult because temperature is so critical for DNA survival. This meant we had to be extremely careful that we did not end up reading contaminating DNA sequences from living, or only recently dead cattle.''