Tag Archives: genetics

The first American dogs were different, and arrived a very long time ago

New genetic research using buried dogs found at two sites in Illinois suggests that the first American dogs came over from Siberia over 16,000 years ago, and were genetically distinct from European dogs.

In the 1960s and 1970s, archaeologists excavated two sites in western Illinois, where ancient hunter-gatherers collected shellfish from a nearby river and stalked deer in surrounding forests. These people also appear to have buried their dogs: One was found at a site known as Stilwell II, and four at a site called Koster, curled up in individual gravelike pits.

Radiocarbon analysis of the bones reveals that they are around 10,000 years old, making these canines the oldest dogs known in the Americas, researchers report on the bioRxiv server. It also makes these the oldest solo dog burials anywhere in the world. The Stilwell II dog was about the size of an English setter, whereas the Koster dogs were smaller and slenderer, says the study’s lead author, Angela Perri, a zooarchaeologist at Durham University in the United Kingdom. “It wouldn’t be surprising if they were all used as hunting dogs.” But where did they come from in the first place?

A second study, published today in Science, may have the answer. A large, international team of researchers sequenced DNA from the mitochondria, or cellular power plants, of 71 North American and Siberian dog bones—including from one of the Koster dogs—dated from about 10,000 to 1000 years ago. When they compared this material, which is passed down only by the mother, to that of 145 modern and ancient dogs, they discovered that the ancient American dogs have a genetic signature not found in any other canines.

There is much uncertainty still about the dates, but not about the genetics. The dogs were larger, resembles wolves, and even howled instead of barked. They were wiped out after the arrival of the Europeans in American, probably because of disease.

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Cats vs dogs in genome research

After an initial focus on studying the genomes of dogs, genetics researchers are now switching to cats.

After the completion of the human, mouse and rat genomes, the US National Institutes of Health organized a commission to decide on their next target; the dog genome was selected for high-quality sequencing, whereas cats were put on hold.

That got some cat geneticists’ backs up. “The truth is there were more powerful people interested in dogs,” says Stephen O’Brien, director of the Theodosius Dobzhansky Center for Genome Bioinformatics in St Petersburg, Russia, who led the initial cat-sequencing efforts.

There is now a project which, for only $7,500, allows scientists to map the genome of any cat for the cause of science. Under this program, they’ve already done 56 cats, including a kitten and her parents.

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