قالب وردپرس درنا توس
Home / Science / Ancient dog DNA reveals 11,000 years of canine evolution

Ancient dog DNA reveals 11,000 years of canine evolution



Papua New Guinea singing dog captive, Papua New Guinea.

The New Guinea singing dog is related to the Australian wild dog.Credit: Daniel Heuclin / NPL

Human history is for dogs. The largest study ever conducted on the ancient genomes of animals has shown that where people have gone, so have their four-legged friends. The study also identified major regional changes in human ancestry, which had little effect on the number of dogs and the time the dogs changed, but the owner did not.

The analysis of more than twenty Eurasian dogs also shows that these animals have been domesticated and spread around the world as early as 1

1,000 years ago. But it did not make any statement about the time or location of the domestication of wolves. This issue has plagued researchers and has led to topics that sometimes arouse heated debate.

Pontus Skoglund, a population geneticist at the Francis Crick Institute in London, said: “Dogs are a separate tracer dye in human history.” The study was published in London on October 29. science1 piece. “Sometimes human DNA may not show the prehistoric parts we can see in the dog genome.”

Until the past few years, the genetic history of dogs was mainly informed by the DNA of modern dogs. But this provides a confusing picture, because the genetic diversity of many early dogs may be lost when modern dog breeds are established. The first study of the ancient dog genome hints at past changes in the dog population. But so far, only six ancient dog or wolf genomes are available. This conclusion is preliminary.

Family Tree Confidant

In order to expand the DNA library of ancient dogs, Skoglund’s laboratory joined a team led by evolutionary geneticist Greger Larson of the University of Oxford and Ron Pinhasi of the University of Vienna. Together, the research team sequenced 27 ancient dog genomes. The samples came from Europe, the Middle East, and Siberia, ranging in age from 11,000 to 100 years old.

By modeling the relationship between ancient and modern dog groups and between them, the researchers determined that a 10,900-year-old dog from Russia is different from later ancient European dogs, Middle Eastern dogs, Siberian dogs or American dogs, and It has canine pedigree from modern New Guinea singing dog (related to Australian dingo). “Already 11,000 years ago, there were at least five different dog groups in the world, so the origin of dogs must have been earlier than this.” Skoglund said.

With so many genomes, researchers can track the movement and mixing of ancient canine populations and compare them with human populations. Sometimes, dog travel parallels human travel. 10,000 years ago, when Middle Eastern farmers began to expand into Europe, they came with dogs, and these animals (like their owners) mixed with the local population. The ancient dogs of the Middle East about 7,000 years ago were related to the modern dogs of sub-Saharan Africa. The latter may be related to the human activities of “returning to Africa” ​​at that time.

But the history of man and dog does not always overlap. 5,000 years ago, a large influx of people from the grasslands of Russia and Ukraine caused a lasting change in the genetic makeup of European humans, not dogs. Research also shows that in the past 4,000 years, the pedigree of European dogs has become less and less, and during this period, the thorough sampling of ancient human DNA showed less turmoil.

Stray dogs

Angela Perri, an animal archaeologist at Durham University in the United Kingdom, said the reason for this disconnect is a mystery. “Are cases such as diseases introduced? Cultural preference? Abandoning the old for the new?” She wondered. “These may be cultural questions that DNA cannot answer.”

Eleanor Carlson, an evolutionary geneticist at the University of Massachusetts School of Medicine in Worcester, said that human sports and cultural preferences are not the only reasons for changing dog pedigrees. She said: “Dogs may begin to exploit humans because they are useful resources to help them survive.” Dogs may move freely, following humans or moving between groups when they suit their interests.

Robert Wayne, an evolutionary biologist at the University of California, Los Angeles, believes that the large-scale analysis of ancient dog genomes is a major advance. He added that to clearly determine the origin of the domestic dog, the same approach must be taken. “This will require detailed collection of samples of wolves and dogs throughout the history of dog domestication.”

Skoglund said that without a large number of even older dog and wolf genomes, “it is really hard to know the initial conquest of the world.”


Source link