From new research into their wolfish origins to development of emotions, from a dog’s eye view to understanding more about how to care for our aging companions, dogs have had a large impact on our lives at Cosmos in 2022.
Doggy descendants
Dogs descended from an ancient and now extinct species of wolf. As canine facts go, this is fairly universally accepted.
When it comes to understanding other details of their evolution such as when and how dogs became so diversified in size, form and ability, however, researchers are still actively sniffing out the clues.
By looking at the lower jawbones of dogs found in archaeological sites around western Europe and Romania dated between 8100 BCE and 3000 BCE, scientists were able to compare the variations and sizes in dogs, dingos and both ancient and modern wolves.
Surprisingly, the researchers found a lot of diversity in dog shapes and sizes tracing as far back to the Late Stone Age in Europe, although extremes of skull size and shape at either end of the scale (think Chihuahua, borzoi or pug) were notably absent.
Evolution for facial flexibility
Somewhere along the road of selective breeding to domestication and their substantial intra-species diversity, dogs developed the ability to form facial expressions.
Tiny mimetic muscles enable facial movements, which ultimately allow the domestic dog to achieve a higher level of facial expressiveness – including holding a human’s gaze – than modern wolf species.
Fibres in human facial muscles were compared with those of the domestic dog and wild grey wolf, with researchers discovering a much higher proportion of ‘fast twitch’ fibres (which are prevalent in humans) in dogs than in their wild cousins. A higher proportion of fast twitch fibres has enabled the domestic dog to faster perform small facial movements – such as raising an eyebrow – which better reflect the expressions of humans.
I’m not crying, the dog is crying…
Just like humans, dogs express emotion by crying.
Unlike humans, though, dogs tend to ‘get something in their eyes’ when they are happy, says new research detailing three tear-jerking experiments.
Researchers looked at tears shed when dogs were reunited with their owner compared with when they were with a stranger, and how oxytocin (a hormone linked to maternal instinct) added to the dogs’ eyes, increased the volume of tears.
The final experiment looked at the effect of visible dog tears on human beings, suggesting that teary eyes led to stronger emotional connections with the dogs.
A new perspective on the world
Functional magnetic resonance imaging (fMRI) has teamed up with machine learning to bring us a dog’s eye view of the world.
Researchers used a video recording selfie stick placed at dog eye level, recording relatable videos for their test subjects, such as scenes with dog ‘actions’ like sniffing, walking or eating, receiving pats and treats from people as well as other object-oriented images such as vehicles, animals and human-human interactions.
By employing machine learning algorithms on fMRI data, researchers were able to reconstruct how the dog’s brain responded to the content they were shown.
Although humans tend to be object-oriented, the dogs showed a preference for action-oriented content including motion and change.
When Fido becomes barking mad with age
A large longitudinal study of aging in dogs in the US has added to our understanding of Canine Cognitive Dysfunction (CCD) – or doggy dementia – and how health, aging and physical activity might play a role in their development.
Researchers have discovered that for every year of their life after age ten, the chance of your canine best friend developing CCD increases by up to 68%.
The data included some 15,000 dogs and their owners, with researchers also uncovering a correlation between inactivity in dogs and their susceptibility to developing CCD.
Originally published by Cosmos as 2022’s best dog stories: some “pawfect” reading to get you through the holiday season
Clare Kenyon
Clare Kenyon is a science journalist for Cosmos. An ex-high school teacher, she is currently wrangling the death throes of her PhD in astrophysics, has a Masters in astronomy and another in education. Clare also has diplomas in music and criminology and a graduate certificate of leadership and learning.
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