For some 9,000 years, the bones of three aurochs – huge, extinct the ancestors modern cattle—languished deep in a cave in northwestern Spain. A team of paleontologists have now genetically sampled the Mesolithic remains, which were found in the 1990s near a human skeleton, and they believe DNA could help unravel the mystery of whether these aurochs were entirely wild or tamed by humans.
To get the mitochondrial DNA from their work, the researchers crushed aurochs bones from nine different sites in Galicia, Spain’s most northwestern region. Of particular interest were the three aurochs found in the Chan do Lindeiro cave, located near the remains of a woman nicknamed Elba, also around 9,000 years old. This opens up a new dilemma as to whether Galicia’s aurochs were wild or tame – how if not, would multiple specimens end up in the same location as a human? The team’s results are published this week in PLOS One magazine.
“In view of all the evidence, such as their similar chronology and the fact that the bones have become entangled at the base of a subsidence caused by the subsidence of the ground – to a depth of 15 to 20 meters – we believe that the woman and aurochs were found together, ”said co-author Aurora Grandal, a researcher at the University of La Coruna, in a Spanish foundation for science and technology Press release. “This interpretation is controversial because domestication is not considered to have existed at the time.”
Of the 18 bone samples taken from aurochs (Bos primigenius), 11 were genetically sequenced. Researchers got insight into the genetic makeup of animals and, by proxy, their relationships with other aurochs across Europe and modern cows. The two species have genetically distinct, haplogroup-tagged subtypes, referring to the large slices of DNA in a given chromosome that distinguish one population from another. Some of these haplogroups are noticeably different: the zebu, or indicine cattle, are more jovial than Jersey cows and have banana-shaped horns and a large hump. (Previously, another team of researchers tried to understand why modern cattle from the Middle East, where aurochs are thought to have been domesticated for the first time, share so much genetic information with indicin cattle).
The aurochs of Chan do Lindeiro cave belonged to the same haplogroup but exhibited a surprising amount of genetic diversity between them. “This may indicate that they were of different origins, in a scenario in which Elba’s wife took an active role; or a trait that simply reflected very high genetic variability in aurochs, ”Grandal said.
“By studying their mitochondrial DNA, which is transmitted almost intact from mother to offspring, we can determine in which geographical areas predominated the different lineages and what were their movements due to changes in climatic conditions or even to humans following the ‘appearance of breeding,’ said co-author Amalia Vidal, a paleontologist at the University of La Coruna, in the same release.
The team found that cave aurochs were more closely related to British aurochs than any other in central Europe. British aurochs specimens, however, are more recent than Spanish specimens, which are so far the oldest to have undergone mitochondrial DNA sequencing. The team’s next step will be to examine nuclearr DNA (which comes from a cell core, rather than its mitochondria, and contains information on all genetic ancestry rather than just matrilineal ancestry) to understand the relationship of aurochs with modern cows in the region. Since the aurochs were found with a woman, it is possible tthat she was guiding them in a way. Nuclear DNA can help answer this question, because nuclear DNA fragments from other aurochs Ancestry has been found in the genetic codes of some modern cattle.
More: Ancient DNA Helps Trace Origin Of Domestic Cattle