---
title: "What the sources say about the Domestic Dog | AnimalTracks.wiki"
description: "50 claims from the Domestic Dog profile, each beside the words of the source that backs it."
image: "https://animaltracks.wiki/images/animals/domestic-dog-1.webp"
canonical: "https://animaltracks.wiki/animals/domestic-dog/sources/"
---

# What the sources say about the Domestic Dog (*Canis lupus familiaris*)

> 50 claims from the Domestic Dog profile, each beside the words of the source that backs it. A "..." marks a cut in a quote and [brackets] an insertion.

Profile: [Domestic Dog](https://animaltracks.wiki/animals/domestic-dog/)

## Craven, Paterson & Settles (2009). The fluid dynamics of canine olfaction: unique nasal airflow patterns as an explanation of macrosmia. Journal of The Royal Society Interface.

https://doi.org/10.1098/rsif.2009.0490

| The page says | The source says |
| :--- | :--- |
| Size and genes are the usual explanation for a **Domestic Dog**'s (*Canis lupus familiaris*) sharp nose, but they leave out how air moves through it | Traditional explanations for canine olfactory acuity, which include large sensory organ size and receptor gene repertoire, overlook the fluid dynamics of odorant transport during sniffing |
| hundreds of millions of scent-sensing cells and nasal airflow tuned to carry smells to them | The canine nasal cavity contains hundreds of millions of sensory neurons ... a unique nasal airflow pattern develops during sniffing, which is optimized for odorant transport to the olfactory part of the nose (note: 'tuned to carry smells to them' renders 'optimized for odorant transport to the olfactory part of the nose') |
| Hundreds of millions of scent-sensing cells, and nostrils that each draw a separate air sample, which may help locate where a smell comes from | The canine nasal cavity contains hundreds of millions of sensory neurons ... during sniffing, spatially separate odour samples are acquired by each nostril that may be used for bilateral stimulus intensity comparison and odour source localization |
| Its nasal cavity holds hundreds of millions of scent-sensing cells in the olfactory epithelium, a lining over the convoluted nasal turbinates at the back of the nose | The canine nasal cavity contains hundreds of millions of sensory neurons, located in the olfactory epithelium that lines convoluted nasal turbinates recessed in the rear of the nose |
| Scientists built a three-dimensional computer model of a dog's nasal passages from MRI scans | a computational fluid dynamics simulation of airflow in an anatomically accurate three-dimensional model of the canine nasal cavity, reconstructed from high-resolution magnetic resonance imaging scans |
| sniffing draws a separate sample of air into each nostril, which may let a dog compare the smell's strength on each side and locate its source | during sniffing, spatially separate odour samples are acquired by each nostril that may be used for bilateral stimulus intensity comparison and odour source localization |
| The airflow pattern inside the nose contrasts sharply with a human's | a unique nasal airflow pattern develops during sniffing, which is optimized for odorant transport to the olfactory part of the nose. These results contrast sharply with nasal airflow in the human. |
| The researchers propose that a dog's sense of smell may depend largely on that airflow, shaped by a highly developed olfactory recess that humans lack | We propose that mammalian olfactory function and acuity may largely depend on odorant transport by nasal airflow patterns resulting from either the presence of a highly developed olfactory recess (in macrosmats such as the canine) or the lack of one (in microsmats including humans) |

## Larson et al. (2012). Rethinking dog domestication by integrating genetics, archeology, and biogeography. Proceedings of the National Academy of Sciences.

https://doi.org/10.1073/pnas.1203005109

| The page says | The source says |
| :--- | :--- |
| The first animal humans domesticated | The dog was the first domesticated animal |
| Not Evaluated | The dog was the first domesticated animal (note: GBIF's copy of the Red List lists Canis lupus familiaris (domestic dog) as Not Evaluated: a domestic taxon, not a wild population under assessment, as on the alpaca and Clydesdale pages. The quote records only that the dog is domesticated. The prefetch resolved this slug to the grey wolf (Canis lupus, LC 2025); that assessment is a different taxon and is not cited. ADW's dog account shows an 'IUCN Red List: Least Concern' badge that appears to carry the wolf's status over and is not used.) |
| The domestic dog was the first animal humans domesticated, though scientists are still not sure when the process began | The dog was the first domesticated animal but it remains uncertain when the domestication process began |

## Bergström et al. (2022). Grey wolf genomic history reveals a dual ancestry of dogs. Nature.

https://doi.org/10.1038/s41586-022-04824-9

| The page says | The source says |
| :--- | :--- |
| Its wild ancestor is the grey wolf, the first species to give rise to a domestic population | The grey wolf (Canis lupus) was the first species to give rise to a domestic population ... the wolf progenitors of the present-day dog lineage |

## Kaminski et al. (2019). Evolution of facial muscle anatomy in dogs. Proceedings of the National Academy of Sciences.

https://doi.org/10.1073/pnas.1820653116

| The page says | The source says |
| :--- | :--- |
| Domestication reshaped more than behavior | Domestication shaped wolves into dogs and transformed both their behavior and their anatomy |
| Dissections of six dogs and four wolves | gray wolves (Canis lupus, n = 4) and domestic dogs (Canis familiaris, n = 6) |
| a muscle called the levator anguli oculi medialis was routinely present in the dogs, while in the wolves it was typically only scant fibers | While the levator anguli oculi medialis muscle (LAOM) was routinely present in dogs, in the gray wolves, it was typically represented only by scant muscle fibers |
| The muscle raises the inner eyebrow intensely | the levator anguli oculi medialis, a muscle responsible for raising the inner eyebrow intensely |
| Filmed as a stranger approached, 27 shelter dogs | in 27 dogs (C. familiaris) and nine wolves (C. lupus). The dogs came from several shelters across the United Kingdom and were observed by a stranger who approached their kennel and filmed their behavior |
| nine wolves from wolf parks | The wolves came from two different wolf parks where they lived in groups and were filmed by a stranger individually |
| made that movement more often and more intensely than | dogs produce the eyebrow movement significantly more often and with higher intensity than wolves do |
| the researchers suggest human preference selected for these "puppy dog eyes" | We hypothesize that dogs with expressive eyebrows had a selection advantage and that “puppy dog eyes” are the result of selection based on humans’ preferences |
| Eye contact seems to raise oxytocin in both the dog and the person | mutual gaze between dogs and humans seems to trigger an increase of oxytocin in both species |
| setting up a feedback loop like the one between human mothers and infants | mutual gaze seems to lead to an oxytocin feedback loop analogous to the one that exists between human mothers and infants (note: continues the sentence 'Eye contact seems to raise oxytocin...', so the source's 'seems' governs this clause too) |
| That loop appears between dogs and humans but not between wolves and humans, which researchers say means domestication must have played an important role in it | this cross-species oxytocin loop can be found in dogs and humans, but not between dogs’ closest living relative (the wolf) and humans, selection processes during domestication must have played an important role (note: 'means ... must have played an important role' follows the source's own 'As this ... loop can be found ..., selection processes ... must have played an important role') |
| dogs raise their inner eyebrows with a muscle wolves barely have | While the levator anguli oculi medialis muscle (LAOM) was routinely present in dogs, in the gray wolves, it was typically represented only by scant muscle fibers (note: vibe.reason, settled in #913; the muscle's action is the 'raising the inner eyebrow intensely' claim) |
| researchers suggest human preference selected for these "puppy dog eyes" | We hypothesize that dogs with expressive eyebrows had a selection advantage and that “puppy dog eyes” are the result of selection based on humans’ preferences (note: vibe.reason, settled in #913) |

## Hart et al. (2013). Dogs are sensitive to small variations of the Earth's magnetic field. Frontiers in Zoology.

https://doi.org/10.1186/1742-9994-10-80

| The page says | The source says |
| :--- | :--- |
| Off the leash in open fields | freely moving dogs (i.e., not on the leash) in “open field” |
| dogs in one study preferred to line up north-south to go to the bathroom, but only while Earth's magnetic field was calm | Dogs preferred to excrete with the body being aligned along the North–South axis under calm MF conditions. This directional behavior was abolished under unstable MF. (note: 'but only while ... calm' renders the two sentences: the preference held under calm MF conditions and was abolished under unstable MF) |
| A 2013 study concluded they do | magnetic sensitivity was proved in dogs (note: 2013 is the paper's publication year (Frontiers in Zoology 10:80, 2013), as listed in the reference) |
| Scientists measured which way 70 dogs of 37 breeds faced during 1,893 bowel movements and 5,582 urinations over two years | We measured the direction of the body axis in 70 dogs of 37 breeds during defecation (1,893 observations) and urination (5,582 observations) over a two-year period |
| When the magnetic field was calm, the dogs preferred to point their bodies along the north-south axis, and that preference vanished when the field was unstable | Dogs preferred to excrete with the body being aligned along the North–South axis under calm MF conditions. This directional behavior was abolished under unstable MF. |
| The best predictor of that switch was how fast the field's declination, its compass direction, was changing during the walk | Relative declination and intensity changes of the MF during the respective dog walks were calculated from daily magnetograms ... The best predictor of the behavioral switch was the rate of change in declination, i.e., polar orientation of the MF (note: 'its compass direction' glosses 'polar orientation') |

## Teng et al. (2022). Life tables of annual life expectancy and mortality for companion dogs in the United Kingdom. Scientific Reports.

https://doi.org/10.1038/s41598-022-10341-6

| The page says | The source says |
| :--- | :--- |
| A UK study of 30,563 dogs that died between 2016 and 2020 put life expectancy at birth at 11.23 years | Among 30,563 dogs that died between 1st January 2016 and 31st July 2020, life expectancy at age 0 was 11.23 |
| among the breeds studied, the Jack Russell Terrier had the longest at 12.72 years and the French Bulldog the shortest at 4.53 | Jack Russell Terrier (12.72 years; 95% CI: 12.53–12.90) and French Bulldog (4.53 years; 95% CI: 4.14–5.01) had the longest and shortest life expectancy at age 0, respectively |
| Breed changed that a lot | Life tables varied widely between breeds. |

## Canis familiaris. AnAge: The Animal Ageing and Longevity Database, Human Ageing Genomic Resources.

https://genomics.senescence.info/species/entry.php?species=Canis_familiaris

| The page says | The source says |
| :--- | :--- |
| AnAge, a longevity database, puts the maximum dog lifespan at 27 years | the maximum longevity of dogs is currently 27 years |
| An Australian cattle dog named Bluey was reported to have lived 29.5 years, but AnAge calls that record unverified | There are anecdotal reports of dogs living around 30 years, including one Australian cattle dog named "Bluey" living 29.5 years. These records are unverified |

## Canis lupus familiaris (dog). Animal Diversity Web, University of Michigan.

https://animaldiversity.org/accounts/Canis_lupus_familiaris/

| The page says | The source says |
| :--- | :--- |
| Alongside people worldwide, in cities, suburbs and farmland | Domestic dogs are found in association with humans worldwide and in a wide variety of habitats ... urban urban suburban suburban agricultural agricultural |
| from tundra to rainforest | tundra tundra taiga taiga desert or dune desert or dune savanna or grassland savanna or grassland chaparral chaparral forest forest rainforest rainforest (note: ADW's Terrestrial Biomes list, first and last-but-one entries) |
| Omnivore: birds, mammals, reptiles, fish, eggs, carrion, insects, seeds, grains, nuts and fruit | Primary Diet omnivore omnivore Animal Foods birds mammals amphibians reptiles fish eggs carrion carrion insects terrestrial non-insect arthropods Plant Foods seeds, grains, and nuts fruit (note: ADW's Food Habits list, shortened (amphibians and non-insect arthropods left out for length)) |
| Selective breeding has produced dogs weighing anywhere from under 1 kilogram to 70 kilograms | They have been selectively bred for millenia for various behaviors, sensory capabilities, and physical attributes ... Range mass <1 to 70 kg |
| Dogs are omnivores: their diet includes birds, mammals, amphibians, reptiles, fish and eggs | Primary Diet omnivore omnivore Animal Foods birds mammals amphibians reptiles fish eggs |
| along with seeds, grains, nuts and fruit | seeds, grains, and nuts fruit |
| They live alongside people worldwide | found in association with humans worldwide |
| in cities, suburbs and farmland | urban urban suburban suburban agricultural agricultural (note: ADW's Other Habitat Features list, each entry doubled on the page) |
| across habitats from tundra and desert to forest and rainforest | tundra tundra taiga taiga desert or dune desert or dune savanna or grassland savanna or grassland chaparral chaparral forest forest rainforest rainforest (note: ADW's Terrestrial Biomes list, each entry doubled on the page) |
| Dogs have been bred for thousands of years for behavior, senses and physical traits, which gave them a bewildering variety of shapes and sizes | Domestic dogs come in a bewildering variety of shapes and sizes. They have been selectively bred for millenia for various behaviors, sensory capabilities, and physical attributes (note: 'thousands of years' renders 'millenia') |
| People bred collies and shepherds to herd, pointers and hounds to hunt, small terriers to catch rats, mastiffs and chows to guard, Newfoundlands and poodles to work fishing nets, huskies and St. Bernards to pull loads, and some breeds, like the Pekingese, simply to sit in a lap and keep it warm | bred for herding livestock (collies, sheperds, etc.), different kinds of hunting (pointers, hounds, etc.), catching rats (small terriers), guarding (mastiffs, chows), helping fishermen with nets (Newfoundlands, poodles), pulling loads (huskies, St. Bernard's), guarding carriages and horsemen (dalmatians), and as companion dogs. Some kinds were even bred simply as lap warmers (Pekingese) |
| The result is a range in mass from under 1 kilogram to 70 kilograms | Range mass <1 to 70 kg |
| dangerLevel: Deadly | In addition, domestic dogs are responsible for attacks on adults and children, sometimes resulting in death. (note: #913: tiers are capabilities; Deadly is 'Capable of killing a human') |
| tags: omnivore | Primary Diet omnivore (note: #913: replaces carnivore; the page's diet line already says omnivore) |