Tuesday , November 24 2020

Researchers are exploring how dogs have come to America




URBANA (AP) – Your poodle may have a French pedigree, but Siberia plays an important role in introducing dogs to America.

This is part of the research conducted at the University of Illinois and the Illinois State Archaeological Survey based on the remains of dogs, including two dogs buried back in one of Illinois, just opposite the Mississippi River in St. Louis.


This loving, ceremonial funeral and about 50 petrified dogs help tell the story, The News-Gazette reports.

This genetic code tells us not only dogs but also people who have crossed a land bridge that once existed between Siberia and Alaska, says Ripan Malhi, professor of anthropology and the School of Integrative Biology.

The State Archaeological Survey in Illinois has opened several places with dogs in them.


Not wanting to destroy valuable scientific and cultural relics, Mali's team took samples of domesticated dogs that may have been nearly 10,000 years old, probably the oldest in America.

"The amount removed is about the size of the (dental) cavity," he said.

Mali works closely with Kelsey Witt Dillon, who manages mitochondrial work with the DNA genome following the mother's line of dogs as a graduate student here. (She is now a postdoctoral researcher at the University of Merced in California.)

In a clean room – no trace of pollutants – the researchers pulled out the DNA. It was then arranged in another lab to create a "genome library".

"DNA will give us millions of DNA bits," Mali said, some of them being polluted long ago by microbes or even by human intervention.

These first dogs in North and South America have arrived from Siberia, said Mali and largely disappeared after European contact, an extreme version of the population decline with local Americans after contact.

During the ice age (lasted some 14,500 years ago) sea level levels were lower, and the area between Western Siberia and East Alaska was an entire land, instead of the Bering Strait we now know. The area is known as "Beringia" and people (and dogs) have managed to cross the bridge bridge due to this lower sea level, added Witt Dillon.

Scientists discuss how genetic dogs are in general extinct from the genetic pool: our ancestors may have killed them to prevent breeding with dogs that have already grown for hunting and flocking, or could be eaten during a hunger.


Disease is the cause that occurs most often, as it is the same with local Americans.

In the journal Science, researchers say the first dogs in America did not tampe with the North American wolves.

Most likely they wrote, the dogs followed satellite people over a land bridge that once connected North Asia through Siberia to America.

At an archeological site near Kahiko, called Janey B. Good, other researchers found dogs with scars on their shoulders.

Malchie said the scars can mean that dogs are not just our best friends, but our colleagues who help to pull out strollers or other types of work similar to their long-term use of sledges in the Northwest.

Mali's specialization is a trace of genetic history, so her articles have titles such as "Spreading Y Chromosomes among Native Americans: Exploring Athapaskan's Population History."

He works closely with the first nations in British Columbia and Alaska, including the study of the precious nutritional resource – salmon.

Nuclear DNA and mitochondrial DNA tell stories in different ways.

Nuclear DNA is the type of DNA that most people probably think – your 23 pairs of chromosomes are all nuclear DNA, and you inherit half of them from your mother and half of them from your father, "explained Vit Dylan.

"Your mitochondrial DNA is inherited from your mother and found in many more copies of a cell than your nuclear DNA, so it's easier to find in ancient DNA samples that are usually degraded and fragmented.

There are questions when and where the dogs are domesticated.

"Dogs are probably domesticated between 15,000 and 21,000 years, somewhere in Europe or Asia," said Witt Dillon. "Europe, the Middle East, Southeast Asia and Central Asia are suggested as places where dogs have emerged, but we still do not have a clear answer."

It is possible that the dogs have appeared in several places of "birth".

By the way, this pole, which ends every dog ​​walk? Pain for you, but of great importance to science as petrified coprolites.

Anthropology student UI Karthik Yarlagadda looks at the microbes in the coprolites working with Mali.

In modern studies, he knows that the tested samples contain a large number of microbes that reflect a number of factors, including host, diet, and the environment.

"Since coprolites are an ancient fecal specimen, they probably still contain some residual DNA from the microbes that lived in the dogs at that time, which is particularly interesting because the ancient microbioms give us additional insight into the individual's life history," he said Jargala.



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