VOA慢速英语--被宣布灭绝50年,新几内亚“唱歌”犬再次现身(在线收听

Ancient New Guinea ‘Singing Dog’ Rediscovered after 50 Years

Researchers say an ancient wild dog known for making unusual "singing" noises has been rediscovered after 50 years.

Scientists had theorized that the breed, called the New Guinea singing dog, had likely gone extinct by the 1970s.

The dogs are native to the Pacific Ocean island of New Guinea, the second largest island in the world. The western half of New Guinea belongs to Indonesia, while the eastern half makes up the independent country of Papua New Guinea.

Researchers say genetic tests have confirmed that the New Guinea singing dog is in fact closely related to wild dogs seen in New Guinea in recent years. That breed is known as the highland wild dog. It is thought to be the rarest and most ancient dog-like animal in existence.

The genetic research was recently reported in a study in Proceedings of the National Academy of Sciences. It uncovered many genetic similarities when comparing the DNA from the two breeds.

Researchers from the National Human Genome Research Institute carried out the study. The institute is part of the U.S. National Institutes of Health, or NIH. Scientists from Indonesia's Cenderawasih University also took part, along with researchers from other educational organizations.

The New Guinea singing dog was first studied in 1897. It became known for its ability to make pleasing, singing-like sounds. The sounds are unlike any produced by other dog populations. The sounds have been described as a "wolf howl with overtones of whale song."

Scientists have estimated that only 200 to 300 New Guinea singing dogs currently exist in captivity in zoos and protective centers. Observations of the highland wild dog are also rare in New Guinea.

There had been reports of highland wild dogs living in an area in Papua New Guinea in 2009, the study noted. But there were only two known cases of highland wild dogs being seen and photographed up until 2016.

"The New Guinea singing dog that we know of today is a breed that was basically created by people," said Elaine Ostrander in a statement. She is an NIH investigator and lead writer of the study. "Eight were brought to the United States from the Highlands of New Guinea and bred with each other to create this group."

Many researchers had suggested that the highland wild dog might have been the predecessor to New Guinea singing dogs. But the lack of sightings and genetic information on highland wild dogs made it difficult to test this theory.

But in 2016, researchers led a trip to a rural mountain area in Papua, Indonesia. The group found 15 highland wild dogs near the Grasberg Mine, the largest gold mine in the world.

A follow-up visit in 2018 permitted researchers to collect blood samples from three highland wild dogs. The samples were examined and compared with DNA from captive New Guinea singing dogs.

Heidi Parker is a scientist with the National Human Genome Research Institute. She said in a statement that the comparisons showed the two breeds had very similar genetic sequences – "much closer to each other than any other" dog-like animals.

The researchers noted that the genetic sequences of the two dogs are not exactly the same. This is likely because of physical separation and continued inbreeding over many years among New Guinea singing dogs.

However, the researchers stated that since the two share such a large number of genetic similarities, "they are, in essence, the same breed." This finding proves that the New Guinea singing dog population "is not extinct in the wild," the researchers added.

The research team says it hopes to start breeding efforts between highland wild dogs and New Guinea singing dogs in captivity to help create "a true New Guinea singing dog population."

Words in This Story

breed – n. a kind of animal

extinct – adj. no longer existing in nature

DNA – n. short for deoxyribonucleic acid -- a substance that carries genetic information in the cells of plants and animals

howl – n. a long, sad sound made by a dog or wolf

overtone – n. something that is suggested, but not clearly stated

predecessor – n. something that comes before another thing in time or in a series

sample – n. a small amount of something that gives you information about the thing it was taken from

sequence – n. the order in which nucleotides (chemical substances) are combined with DNA

in essence – phr. relating to the most important characteristics or ideas of something

  原文地址:http://www.tingroom.com/voa/2020/9/512120.html