Tag Archives: domestication of dogs

Wolves, dogs and dingoes

Dogs are generally considered the first domesticated animal, while its ancestor is generally considered to be the wolf, but where the Australian dingo fits into this framework is still debated, according to a retired Penn State anthropologist.

“Indigenous Australians understood that there was something different about the dingoes and the colonial dogs,” said Pat Shipman, retired adjunct professor of anthropology, Penn State.  “They really are, I think, different animals. They react differently to humans. A lot of genetic and behavioral work has been done with wolves, dogs and dingoes. Dingoes come out somewhere in between.”

A) Person holding the front paws of a dingo spread wide.  B) Shows a dingo climbing rocks. Image: Lyn Watson

Wolves, dogs and dingoes are all species of the canidae family and are called canids. In most animals, hybridization between closely related species does not happen, or like female horses and male donkeys, produce mules — usually non-fertile offspring.  However, many canid species, including wolves, dingoes and dogs, can interbreed and produce fertile offspring. Defining species boundaries in canids becomes more difficult.

Domestic dogs came to the Australian continent in 1788 with the first 11 ships of convicts, but dingoes were already there, as were aboriginal Australians who arrived on the continent about 65,000 years ago. A large portion of dingoes in Australia today have domestic dog in their ancestry, but dingoes came to Australia at least 4,000 years ago according to fossil evidence. Shipman believes that date may be even earlier, but no fossils have yet been found.

“Part of the reason I’m so fascinated with dingoes is that if you see a dingo through American eyes you say, ‘that’s a dog,'” said Shipman. “In evolutionary terms, dingoes give us a glimpse of what started the domestication process.”

Shipman reports her analysis of wolves, dogs and dingoes in a January 2021 special issue of the Anatomical Record.

Dingoes, and the closely related New Guinea singing dogs, look like the default definition of dog, but they are not dogs. 

“There is a basic doggy look to dingoes,” said Shipman.

Genetically and behaviorally they differ from dogs and are more like wolves in their inability to digest starches and their relationships with humans. 

Most domestic dogs evolved along with humans as humans became agriculturalists and moved to a diet containing large amounts of starch, whether from maize, rice, potatoes or wheat. Their genome changed to allow the digestion of these starches. Dingoes, like wolves, have very few of the genes for starch digestion.

While indigenous Australians stole dingo puppies from their dens and raised them, these puppies generally left human homes at maturity and went off to breed and raise offspring. The ability to closely bond with humans is limited in dingoes, although present in dogs. Native Australians also did not manipulate dingo breeding, which is a hallmark of domestication.

Dingoes are also well-adapted to the Australian outback and fare well in that environment. Domestic dogs that become feral do not survive well in the outback.

“Aboriginal Australians were not well-regarded as holders of knowledge or special skill when Europeans came to the continent,” said Shipman. “So, no one thought to ask them about dingoes. Even recently, asking aboriginals for their scientific or behavioral knowledge really was not common.”

However, aboriginal Australians have a long history of living with dingoes in their lives. Many people argue that dingoes are just dogs — strange dogs, but just dogs, said Shipman.  But, according to aboriginals, dingoes are not dogs.

With dingoes showing behaviors somewhere between wolves and dogs and exhibiting only slight genetic ability to consume starchy foods or tolerate captivity, Shipman concluded that “A dingo is a wolf on its way to becoming a dog, that never got there.”

Source: Penn State News

Domestication of dogs and the culling of mammoths

Adjunct Professor at Penn State, Pat Shipman, believes that the abrupt appearance of large numbers of dead mammoths may have been caused by early humans hunting with the first domesticated dogs.

Spectacular archaeological sites yielding stone tools and extraordinary numbers of dead mammoths — some containing the remains of hundreds of individuals — suddenly became common in central and eastern Eurasia between about 45,000 and 15,000 years ago, although mammoths previously had been hunted by humans and their extinct relatives and ancestors for at least a million years.

A fragment of a large bone, probably from a mammoth, Pat Shipman reports, was placed in this dog's mouth shortly after death. This finding suggests the animal was according special mortuary treatment, perhaps acknowledging its role in mammoth hunting. The fossil comes from the site of Predmosti, in the Czech republic, and is about 27,000 years B.P. old. This object is one of three canid skulls from Predmosti that were identified as dogs based on analysis of their morphology. Photo credit: Anthropos Museum, Brno, the Czech Republic, courtesy of Mietje Germonpre.

A fragment of a large bone, probably from a mammoth, Pat Shipman reports, was placed in this dog’s mouth shortly after death. This finding suggests the animal was according special mortuary treatment, perhaps acknowledging its role in mammoth hunting. The fossil comes from the site of Predmosti, in the Czech republic, and is about 27,000 years B.P. old. This object is one of three canid skulls from Predmosti that were identified as dogs based on analysis of their morphology. Photo credit: Anthropos Museum, Brno, the Czech Republic, courtesy of Mietje Germonpre.

“One of the greatest puzzles about these sites is how such large numbers of mammoths could have been killed with the weapons available during that time,” Shipman said.

Surprisingly, Shipman said, she found that “few of the mortality patterns from these mammoth deaths matched either those from natural deaths among modern elephants killed by droughts or by culling operations with modern weapons that kill entire family herds of modern elephants at once.” This discovery suggested to Shipman that a successful new technique for killing such large animals had been developed and its repeated use over time could explain the mysterious, massive collections of mammoth bones in Europe.

The key to Shipman’s new hypothesis is recent work by a team led by Mietje Germonpré of the Royal Belgian Institute of Natural Sciences, which has uncovered evidence that some of the large carnivores at these sites were early domesticated dogs, not wolves as generally had been assumed. Then, with this evidence as a clue, Shipman used information about how humans hunt with dogs to formulate a series of testable predictions about these mammoth sites.

Shipman’s research has been published in the journal Quaternary International and is entitled “How do you kill 86 mammoths?”

For more information about this research and related studies, read the full Penn State media statement.

Pet obesity at the molecular level

A University of Illinois research team led by Professor Kelly Swanson has published research which describes how nutrients and biological compounds in foods can affect gene expression in animals.

The research will help to understand the underlying reasons for obesity in pets.  Professor Swanson explains that obesity has its roots in the domestication of dogs.  Because dogs no longer hunt or compete for their food and are speyed or neutered (so not having to mate),  the typical dog has much smaller energy requirements than its forefathers.

The research team explains that when more energy (food) is consumed than is required, it is stored as fat in the adipose tissue (fat tissue).  Adipose tissue secretes more than 50 substances known as adipokines, which are cell-signaling molecules that are involved in metabolism, immunity and inflammation.

In obese dogs, levels of the adipokine leptin increases while the levels of the  adipokine adiponectin decreases.

The researchers aim to study obesity at the molecular level, so they can help to prevent it happening.

Source:  University of Illinois media statement