Posts Tagged: Dogs


14
Mar 10

Small Dogs Have Middle Eastern Origins

I’ll be blunt. I’m not a fan of small dogs. (I tend to consider them “large rats”.) However, I am a fan of dog genetics.

A genetic study has found that small domestic dogs probably originated in the Middle East more than 12,000 years ago. Researchers writing in the open access journal BMC Biology traced the evolutionary history of the IGF1 gene, finding that the version of the gene that is a major determinant of small size probably originated as a result of the domestication of the Middle Eastern gray wolf.

Melissa Gray and Robert Wayne, from the University of California, Los Angeles, led a team of researchers who surveyed a large sample of gray wolf populations. She said, “The mutation for small body size post-dates the domestication of dogs. However, because all small dogs possess this variant of IGF1, it probably arose early in their history. Our results show that the version of the IGF1 gene found in small dogs is closely related to that found in Middle Eastern wolves and is consistent with an ancient origin in this region of small domestic dogs.”

(Emphasis mine.)

(Link)


21
Feb 10

Dog Morality

Seems that dogs, wolves, and coyotes posses morality, and that morality is similar to human morality.

Looking for the roots of human morality in the animal kingdom? Focus on canines, who know how to play fair
[...]
Every dog owner knows a pooch can learn the house rules—and when she breaks one, her subsequent groveling is usually ingratiating enough to ensure quick forgiveness. But few people have stopped to ask why dogs have such a keen sense of right and wrong. Chimpanzees and other nonhuman primates regularly make the news when researchers, logically looking to our closest relatives for traits similar to our own, uncover evidence of their instinct for fairness. But our work has suggested that wild canine societies may be even better analogues for early hominid groups—and when we study dogs, wolves and coyotes, we discover behaviors that hint at the roots of human morality.

Morality, as we define it in our book Wild Justice, is a suite of interrelated other-regarding behaviors that cultivate and regulate social interactions. These behaviors, including altruism, tolerance, forgiveness, reciprocity and fairness, are readily evident in the egalitarian way wolves and coyotes play with one another. Canids (animals in the dog family) follow a strict code of conduct when they play, which teaches pups the rules of social engagement that allow their societies to succeed. Play also builds trusting relationships among pack members, which enables divisions of labor, dominance hierarchies and cooperation in hunting, raising young, and defending food and territory. Because this social organization closely resembles that of early humans (as anthropologists and other experts believe it existed), studying canid play may offer a glimpse of the moral code that allowed our ancestral societies to grow and flourish.

(Link)


24
Jan 10

Urban Dog Behavior Adaptations in Moscow

There’s an interesting article on dog behavior (H/T Razib Khan): "Moscow’s stray dogs"….

[...] It has become a symbol for the 35,000 stray dogs that roam Russia’s capital – about 84 dogs per square mile. You see them everywhere. They lie around in the courtyards of apartment complexes, wander near markets and kiosks, and sleep inside metro stations and pedestrian passageways. You can hear them barking and howling at night. And the strays on Moscow’s streets do not look anything like the purebreds preferred by status-conscious Muscovites. They look like a breed apart.

I moved to Moscow with my family last year and was startled to see so many stray dogs. Watching them over time, I realised that, despite some variation in colour – some were black, others yellowish white or russet – they all shared a certain look. They were medium-sized with thick fur, wedge-shaped heads and almond eyes. Their tails were long and their ears erect.

(Emphasis mine.)

I think it would be premature to just assume that this look has developed as an or due to an adaptation. (I.e., you need to back up such a claim.) But it is definitely an area one would want to research.

There’s some evidence to suggest that when dogs go feral, they tend to eventually look like the (Australian) dingo. (For example, the Carolina dog looks similar to a dingo.) But I’d imagine that this might not be the only phenotype for feral dogs; as different environments may lead to different feral dog phenotypes.

They also acted differently. Every so often, you would see one waiting on a metro platform. When the train pulled up, the dog would step in, scramble up to lie on a seat or sit on the floor if the carriage was crowded, and then exit a few stops later. There is even a website dedicated to the metro stray (www.metrodog.ru) on which passengers post photos and video clips taken with their mobile phones, documenting the ­savviest of the pack using the public transport system like any other Muscovite.

Quite interesting as well.

Where did these animals come from? It’s a question Andrei Poyarkov, 56, a biologist specialising in wolves, has dedicated himself to answering. His research focuses on how different environments affect dogs’ behaviour and social organisation. About 30 years ago, he began studying Moscow’s stray dogs. Poyarkov contends that their appearance and behaviour have changed over the decades as they have continuously adapted to the changing face of Russia’s capital. Virtually all the city’s strays were born that way: dumping a pet dog on the streets of Moscow amounts to a near-certain death sentence. Poyarkov reckons fewer than 3 per cent survive.
[...]
[O]n average, [they] are much less aggressive and a good deal more tolerant of one another [than wolves],” says Poyarkov. Wolves stay strictly within their own pack, even if they share a territory with another. A pack of dogs, however, can hold a dominant position over other packs and their leader will often “patrol” the other packs by moving in and out of them. His observations have led Poyarkov to conclude that this leader is not necessarily the strongest or most dominant dog, but the most intelligent – and is acknowledged as such. The pack depends on him for its survival.

(Emphasis mine.)

I think this would definitely warrant some kind of dog intelligence testing. (Especially a test that doesn’t rely on obedience.)


24
Jan 10

Aspie Dogs?

Well, maybe not quite an Aspie dog, but canine obsessive compulsiveness seems to be similar to human obsessive compulsiveness.

(Note the usual caveats about them labeling this behavior as a “disorder” where I don’t think that’s accurate, in the layman idea of what a “disorder” is.)

A canine chromosome 7 locus that confers a high risk of compulsive disorder susceptibility has been identified through a collaboration between the Behavior Service at the Cummings School of Veterinary Medicine, the Program in Medical Genetics at the University of Massachusetts Medical School and the Broad Institute at the Massachusetts Institute of Technology. The findings are published in the January 2010 edition of Molecular Psychiatry.

Obsessive compulsive disorder is characterized by time consuming, repetitive behaviors and affects about 2 percent of humans, while the equally distressing canine equivalent, canine compulsive disorder, or CCD, seems to target certain dog breeds, especially Dobermans and Bull Terriers. [...]

The chromosome 7 location most significantly associated with CCD is located within the neural cadherin-2 gene, CDH2. CDH2 is widely expressed, mediating synaptic activity-calcium flux related neuronal adhesion. Dogs showing multiple compulsive behaviors had a higher frequency of the “risk” associated DNA sequence than dogs with a less severe phenotype (60 and 43%, respectively, compared with 22% in unaffected dogs). This highly significant association of CCD with the CDH2 gene region on chromosome 7 is the first genetic locus identified for any animal compulsive disorder, and raises the intriguing possibility that CDH2 and other neuronal adhesion proteins are involved in human compulsive behaviors, including those observed in autism spectrum disorder. [...]

“The CDH2 gene is expressed in the hippocampus, a brain region suspected to be involved in OCD. In addition, this gene oversees structures and processes that are possibly instrumental in propagating compulsive behaviors — for example, the formation and proper functioning of glutamate receptors,” said Dr. Nicholas Dodman, professor of clinical sciences at Cummings School of Veterinary Medicine at Tufts University and the study’s lead author. Dr. Dodman added that “this finding is congruent with current evidence that NMDA blockers are effective in the treatment of OCD.”

The occurrence of repetitive behaviors and similarities in response to drug treatments in both canine CCD and human OCD suggest that common pathways are involved” [...]

(Link)


19
Jan 10

Dog Genetics and Domestication

Interesting study on the genetics of dogs. The comparisons they are making with dog domestication and recent evolution in humans is interesting.

Although domestication of dogs began over 14,000 years ago [...] the spectacular diversity among breeds is thought to have originated during the past few centuries through intense artificial selection of and strict breeding for desired characteristics. [E]ffort[s] [are underway] to map canine genome regions that show signs of recent selection and that contain genes that are prime candidates for further investigation. Those genes are being examined for their possible roles in the most conspicuous variations among dog breeds: size, coat color and texture, behavior, physiology, and skeleton structure.

The researchers performed the largest genome-wide scan to date for targets of selection in purebred dogs. The genomes came from 275 unrelated dogs representing 10 breeds that were very unlike each other. The breeds were: Beagle, Border Collie, Brittany, Dachshund, German Shepherd, Greyhound, Jack Russell Terrier, Labrador Retriever, Shar-Pei, and Standard Poodle.

The study was conducted, the researchers said, because the canine genome, the product of centuries of strong selection, contains many important lessons about the genetic architecture of physical and behavioral variations and the mechanisms of rapid, short-term evolution. The findings, the researchers said, “provide a detailed glimpse into the genetic legacy of centuries of breeding practices.”
[...]
Their list of most differentiated regions of the dog genome included five genes already linked to hallmark traits of certain breeds: one for small size, one for short limbs like those in Dachshunds and other stubby-legged dogs, and three for coats.
[...]
A major impetus behind studying dog genomics, the researchers pointed out, is its potential to advance knowledge about the genetic basis of human form variations and of differences in disease susceptibility among people. In many cases, the researchers said, it may be easier to locate the genetic targets of selection in dogs, and then map these to related regions in the human genome. Scientists are intrigued by the possibility that recent selection may have affected genome regions common to both human and dog lineages.

“This research has shown that artificial selection in dogs has acted on many of the same genes as natural selection in humans, and that many of these genes are regulators of gene activity,” [...]

The researchers also said that a better understanding of artificial selection in dogs may reveal the molecular mechanisms of rapid, short-term evolution. Future work, they hope, may uncover the gene activities responsible for shaping the incredible diversity among the world’s dogs.

(Emphasis mine.)

(Link)