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Mia Persson
Mia Persson

Your Dog's Interest in You Might Be Genetic

Mia Persson
Mia Persson

The love affair between dogs and people is an old one indeed, stretching back at least 15,000 years. Dogs are our coworkers, guides, companions, and family members. But how did they get that way? A paper published in Scientific Reports proposes an intriguing possibility: dogs have a genetic predisposition to crave human companionship.

Previous studies have suggested a genetic component to the domestication of dogs. To further test that hypothesis, five researchers from Linköping University in Sweden assembled an enormous group of 437 laboratory-raised beagles and gave each one an impossible test. Each dog was brought to a room containing a box with three dishes, and each dish held a treat. To get the treat, the beagle needed to figure out how to slide the cover off the container. But there was a catch: one of the containers was covered with transparent Plexiglas and would not yield its treat no matter what the confused beagle did.

The dog was not alone in the testing room; each was accompanied by a seated researcher, who looked away while the dog wrestled with the puzzle box. The real test came when each dog realized it could not retrieve the last treat. At this point, some dogs gave up and started walking around the room. But others—many others—looked to or approached the researcher for help, a behavior that demonstrated their interest in people.

Each dog’s test was videotaped and its reactions coded and quantified. The researchers then identified the 95 most sociable dogs and the 95 least sociable dogs, and sequenced their genomes, looking for trends.

They found them. The most sociable dogs showed activation in two highly specific genomic regions. The presence of a single marker on the 26th chromosome of the SEZ6L gene was a significant indication that a beagle would have spent more time near and physically touching the researcher during the test. Another two markers on chromosome 26 of the ARVCF gene were strongly associated with seeking out human contact.

These genomic regions are not unique to dogs and, the researchers say, their role in socialization may not be either. Studies in humans have found a relationship between changes in SEZ6L and autism. ARVCF has been linked to schizophrenia, as have COMT and TXNRD2, which both hail from the same genetic neighborhood.

“This is, to our knowledge, the first genome-wide study presenting candidate genomic regions for dog sociability and inter-species communication,” the authors write. They acknowledge that more research is needed to validate their findings. Still, they say, “these results contribute to a greater insight into the genetic basis of dog-human communicative behaviors and sociability, increasing our understanding of the domestication process, and could potentially aid knowledge relating to human social behavioral disorders.”

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Animals
Where Do Birds Get Their Songs?
iStock
iStock

Birds display some of the most impressive vocal abilities in the animal kingdom. They can be heard across great distances, mimic human speech, and even sing using distinct dialects and syntax. The most complex songs take some practice to learn, but as TED-Ed explains, the urge to sing is woven into songbirds' DNA.

Like humans, baby birds learn to communicate from their parents. Adult zebra finches will even speak in the equivalent of "baby talk" when teaching chicks their songs. After hearing the same expressions repeated so many times and trying them out firsthand, the offspring are able to use the same songs as adults.

But nurture isn't the only factor driving this behavior. Even when they grow up without any parents teaching them how to vocalize, birds will start singing on their own. These innate songs are less refined than the ones that are taught, but when they're passed down through multiple generations and shaped over time, they start to sound similar to the learned songs sung by other members of their species.

This suggests that the drive to sing as well as the specific structures of the songs themselves have been ingrained in the animals' genetic code by evolution. You can watch the full story from TED-Ed below, then head over here for a sample of the diverse songs produced by birds.

[h/t TED-Ed]

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NOAA, Wikimedia Commons // Public Domain
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Animals
Watch the First-Ever Footage of a Baby Dumbo Octopus
NOAA, Wikimedia Commons // Public Domain
NOAA, Wikimedia Commons // Public Domain

Dumbo octopuses are named for the elephant-ear-like fins they use to navigate the deep sea, but until recently, when and how they developed those floppy appendages were a mystery. Now, for the first time, researchers have caught a newborn Dumbo octopus on tape. As reported in the journal Current Biology, they discovered that the creatures are equipped with the fins from the moment they hatch.

Study co-author Tim Shank, a researcher at the Woods Hole Oceanographic Institution in Massachusetts, spotted the octopus in 2005. During a research expedition in the North Atlantic, one of the remotely operated vehicles he was working with collected several coral branches with something strange attached to them. It looked like a bunch of sandy-colored golf balls at first, but then he realized it was an egg sac.

He and his fellow researchers eventually classified the hatchling that emerged as a member of the genus Grimpoteuthis. In other words, it was a Dumbo octopus, though they couldn't determine the exact species. But you wouldn't need a biology degree to spot its resemblance to Disney's famous elephant, as you can see in the video below.

The octopus hatched with a set of functional fins that allowed it to swim around and hunt right away, and an MRI scan revealed fully-developed internal organs and a complex nervous system. As the researchers wrote in their study, Dumbo octopuses enter the world as "competent juveniles" ready to jump straight into adult life.

Grimpoteuthis spends its life in the deep ocean, which makes it difficult to study. Scientists hope the newly-reported findings will make it easier to identify Grimpoteuthis eggs and hatchlings for future research.

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