A dental filling that lasted 6,500 years
Ancient dentistry has been discovered in a 6,500-year-old human jawbone: a lump of beeswax that appears to be the earliest evidence of a dental filling. The beeswax was probably applied to ease pain from a crack in the enamel and dentin layers of the tooth,said Claudio Tuniz,a nuclear paleoanthropologist at the Abdus Salam International Center for Theoretical Physics in Italy.
He and his colleagues report their findings in the journal PLoS One.
The jawbone was discovered in 1911,embedded in a rock inside a cave in what is now Slovenia. For many years it was left unstudied in the Museum of Natural History in Trieste,Italy.
With radiocarbon analysis,the researchers determined that both the tooth and the beeswax were 6,500 years old.
The Neolithic people that lived in the area at the time were primarily involved in breeding sheep,Federico Bernardini,an archaeologist at the centresaid.
They probably used their teeth as a third hand, he saida tool to hold thread when weaving,for instance. Evidence of prehistoric dentistry is rare,but it exists. Tooth drilling,for instance,is known to have occurred in what is now Pakistan more than 7,500 years ago.
Catss stripes and spot tracked
The gene that produces the striking dark stripes on tabby cats is also responsible for the spots on cheetahs,a new study reports. And a mutation of this same gene causes the stripes in cats and spots on cheetahs to become blotchy.
Nobody had any idea what the genes were that were involved in these things, said Stephen OBrien,a geneticist now at St. Petersburg University in Russia and one of the researchers who led the study. When the feline genome became available,we began to look for them.
OBrien and his colleagues published their discovery of the gene,known as Taqpep,in the current issue of the journal Science. Cheetahs that have the Taqpep mutation belong to a rare breed found in South Africa. Tabbies with the mutation are more often found in Europe,OBrien said.
The researchers used DNA samples and tissue samples from feral cats in Northern California,along with small skin biopsies and blood samples from captive and wild South African and Namibian cheetahs. The scientists also discovered a second gene,Edn3,that controls hair colour in the cats coat patterns.
There is more work to be done in looking at other genes,and at other cats both domestic and wild,OBrien said.