Pack mentality

As hard as it may be to imagine, dogs -- yes, all of them -- are the domesticated descendants of gray wolves.

Well, it's hard for me to imagine, anyhow.  I have three dogs whose wolf ancestry is, shall we say, rather well hidden.

This is Jethro.  He's half Plush Toy and half Dust Bunny.

This is Guinness, who is a full-blooded Tennis Ball Retriever.  He is also a very dapper gentleman.

And this is Rosie, who has had just about enough of your shit.

None of them, let's say, exactly screams out "Alpha Wolf of the Deep Forest Pack."  But nevertheless, all three of them descend from wolves that were domesticated by our distant ancestors something like twenty thousand years ago, in an encounter that went something like this:

Wolf (snarling): I will terrorize your villages, decimate your livestock, and eat your children!

Early human:  We have sofas, peanut butter, and squeaky toys.

Wolf:  ... I'm listening

What's fascinating is that despite a lot of selective breeding since then, wolves and dogs are still cross-fertile.  It's yet another example of how we think we have a good definition for the word species, then we keep finding exceptions, or at least situations that leave you thinking, "Wait... those are the same species?"  But yes: by the canonical definition of species -- a population whose members are capable of interbreeding and producing fertile offspring -- dogs and wolves are the same species.

And new research by a team from the American Museum of Natural History and the Smithsonian Institution has found something even more astonishing; since domestication, dogs have been backcrossed to wolves multiple times, meaning that since domestication, wolf genetics has been reintroduced into dog lineages over and over.

Not always how you'd expect, either.  It isn't just "big dogs = lots of recent wolf ancestry, small dogs = not so much."  Mastiffs and Saint Bernards both show close to zero reintroduced wolf DNA.  Even chihuahuas have more (at around 0.2%).  The highest amount, unsurprisingly, is amongst the breeds associated with pulling sleds -- huskies, malamutes, Samoyeds, and Greenland dogs.  But most dog breeds have somewhere between two and five percent recent wolf ancestry, even the ones you might not suspect.

What's also fascinating is that the amount of recent wolf ancestry correlates strongly to personality.  Breeds were given descriptors by dog breeders and owners, and a significant pattern emerged.  Low recent wolf ancestry correlated to a breed being described as “friendly,” “eager to please,” “easy to train,” “courageous,” “lively,” or “affectionate.”  High wolf ancestry breeds were more likely to be described as “suspicious of strangers,” “independent,” “dignified,” “alert,” “loyal,” “reserved,” or “territorial.”

John Heywood's comment that what's bred in the bone comes out in the flesh apparently applies to dogs as well as humans.

It makes me wonder about how wolfy my own dogs are.  Jethro, I suspect, is pretty low on the scale.  High wolf ancestry is also correlated with intelligence, and -- to put not too fine a point on it -- Jethro has the IQ of a tuna salad sandwich.  I suspect Guinness is on the high end, because he's part husky, and also checks off most of the boxes for the personality traits of high wolf ancestry dogs.  Rosie is mostly Australian cattle dog, and she's probably in the middle.  All I know is that she's extremely sweet, stubborn as hell, and can give you a reproachful look that makes you feel like you have disappointed not only her, but all of her ancestors.

In any case, this is all an excellent example of introgression -- where populations that initially come from a common ancestry are repeatedly backcrossed to the wild type.  And that, plus twenty thousand years of selective breeding, is why we have the great variety of dogs we have.

But you'll have to excuse me.  Guinness wants to play ball.  I wonder if "extremely demanding and will not take no for an answer" is a wolf trait?

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Going to the dogs

I understand dogs a great deal better than I understand my fellow humans.

Dogs are straightforward.  They interact with their world in a direct way, whether it be motivated by love, anger, curiosity, hunger, enthusiasm, or fear.  There's nothing feigned about a dog's emotions or the way they express them.  I've sometimes misinterpreted one of my dogs' signals, but that's on me; the signals were there, even if I only recognized them in retrospect.  Once you grok dog behavior, it's much less fraught than the complex, confusing morass of human interaction.

This is why when I'm invited to social events, I'm always hoping the host will have a dog so there'll be someone for me to have a conversation with.

The dogs we've had have nearly all been rescues, and came with all the baggage and bad backstories that rescue dogs have, but one and all were and are wonderful companions, and enriched our lives tremendously.  This latter part is the only possible explanation for why during the holidays, my wife and I were looking around and thinking, "Wow, our house sure has a lot of clutter and dirt and chaos.  We never seem to be able to keep up with the housekeeping.  Hey, I know... let's get a puppy!"

So, without further ado, allow me to introduce to the Skeptophilia readership...

... Jethro.

Jethro is -- and I say this with all modesty and restraint -- the cutest puppy in the whole entire world.  He's five months old, has the sweetest, happiest disposition ever, and soft, silky hair that gathers burs, mud, and debris like some sort of bizarre magnet.  Like many puppies, he has two settings -- "Full Throttle" and "Off."

He's currently set at "Off" and is sleeping at my feet, which is the only way I'm able to write this.  Otherwise I would be engaged in the essential task of Playing With Jethro.

We got him from the amazing Stay Wild Rescue and Wildlife Rehabilitation Center on New Year's Eve.  If you are looking for a wonderful and deserving place to make a donation, please consider Stay Wild.  They do fantastic work on a shoestring budget, and the owners -- Jane George and Dan Soboleski -- work tirelessly to help find rescue pets forever homes, and to rehabilitate wild animals for re-release.  Please check out their website and consider supporting them.

In the few days we've had Jethro, he's already bonded with our other two dogs, Guinness and Rosie.  Rosie is an Australian Cattle Dog mix who pretty much loves everyone, so she was easy.

Guinness is a big galumphing American Staffordshire Terrier/Husky/Chow cross who can be cranky and gets jealous easily, especially when it comes to sharing Carol's attention with anyone, because he's a big ol' Mama's Boy.  He is, however, a very natty dresser. 

But yesterday, all three of them were romping around together in the back yard, and Guinness was letting Jethro chase him like they'd been best friends forever instead of just three days.  Guinness even responded with the doggie "play-bow" before they took off running again.

Like with most rescues, we're not sure what kind of a mix Jethro is.  Jane at Stay Wild said she thought he had some Golden Retriever in him, which makes sense given his silky coat and general head shape, but his striking and beautiful black face and brindle coloration have to come from somewhere else.  He's got huge paws, indicating he's got some serious growing to do, but whether he'll turn out to be long and lanky or barrel-chested and stocky is anyone's guess.  Dog-loving friends of mine have speculated a lot of possible contributions to his ancestry -- suggestions have included various spaniels and setters, Border Collie, Boxer, German Shepherd, even Saint Bernard -- but we won't be sure until we have him DNA-tested.  (The kit has already been ordered.)

A photo of Jethro from five minutes ago, because why not

It's tempting to say his lovable, playful temperament is indicative of his Golden Retriever genes, but a surprising study at the University of Massachusetts just last year found the contribution of breed to behavior is way smaller than most people think.  We often associate particular behavioral traits with certain types of dog -- labs are friendly and loyal, hounds laid-back but stubborn, Dalmatians nervous and prone to biting, and so on -- but the researchers found exceptions to the rule are so common that the rule isn't really a rule.  And while we've had dogs who seemed to conform to the breed expectations, all of them have their own unique characteristics and quirks.

Dogs are as varied in personality as people are, I suppose.

In any case, now we've got three dogs.  I commented yesterday that this means we're outnumbered, and that it's a good thing this is a benevolent dictatorship and not a democracy.  Although a friend of mine responded, "I'm sure your dogs would vote for you anyway."

Given the fact that Jethro is snoozing happily right next to me, I suspect my friend is right.

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Canine DNA analysis

When we adopted our latest rescue dog, Guinness, the people at the shelter told us that he was a Black Lab/Akita mix.  He certainly looks like it:

But I've heard from a lot of people that the assessments made at shelters are guesses at best, so a few months ago we had him DNA tested.  The results:

He is neither Black Lab nor Akita.

The test gave us the following results, most of which seem spot-on.  The largest portion of his ancestry is Staffordshire Terrier, which is one of the breeds from which Pit Bulls are bred.  He has the broad chest and blocky head of a pitty for sure.  The next three on the list were Husky, Chow, and Dalmatian.  He's got a curly tail and a thick, sleek coat, so those make some sense as well.  The only one I'm not buying is the last one on the list, which is Bichon Frisé, which (for the non-doggy people in the audience) is a small white dog that looks like a cross between a poodle and a cotton ball.

Maybe the white splotch on his chest and the tips of his toes are from his Bichon ancestry, I dunno.  Or maybe one just ran into him at some point, and that's the splat mark.

So okay, maybe the DNA tests have their issues, too.  But at least the majority of it makes sense, from his appearance and personality, the latter of which is seventy pounds of spring-loaded bounce.  He has two settings: full throttle and off.  Our mellow old coonhound, Lena, frequently looks at him with this expression that says, "Dude, you have got to switch to decaf."

This all comes up because of a study out of Arizona State University that appeared in PLoS-One a couple of weeks ago.  Titled, "More Than a Label: Shelter Dog Genotyping Reveals Inaccuracy of Breed Assignments," the researchers took DNA samples from nine hundred shelter dogs and ran a full genotypic analysis on them.  The results were startling; they found ancestry from 125 different breeds, and the accuracy of the breed assignment by the shelter was only ten percent.

It shouldn't be surprising; the handful of genes that codes for basic body shape and features like coat color, eye color, ear shape, and so on, and relatively responsive to selective breeding, and since that's what we're basing our assessment on, it stands to reason we'd get misled.  If you keep selecting the same thing over and over in two unrelated lineages, you'll eventually end up with their progeny looking like each other.  (This is called convergent evolution and is why the marsupial sugar glider and the flying squirrel are so strikingly similar; it's also why distantly-related groups of humans who live near the equator all have dark skin despite not sharing recent ancestry.)

"Breed identification has quite an outsize role in people's perceptions of dogs," said Clive Wynne, professor of psychology and head of the Canine Science Collaboratory at ASU, and co-author of the study.  "'What breed is he?' is often the first question people ask about a dog, but the answer is often terribly inaccurate."

As far as Guinness, I did ask what breed he was, but it was more out of curiosity than any kind of deciding factor regarding our potentially adopting him.  I fell for him right away, and he's turned out to be a sweetheart, despite being (and I say this with the utmost affection) a big galoot.  (Which my wife tells me in Latin translates to "galooteus maximus."  We are all about multilingual wordplay in this family.)

But it's still interesting how far wrong they were.  I get why they thought "Black Lab," with his shiny, thick, jet-black coat; it never really occurred to me to question it.  When I got the test results back, I was pretty stunned.

I guess it's no wonder, though, with a 90% fail rate.

So anyhow, keep adopting rescue animals -- it's the best way to go.  We've always gotten rescues and never gone wrong.  But don't necessarily believe what they tell you about the breed.

Now, I gotta go, because Guinness is ready to play his sixth round of "fetch the rubber ball over and over."  Simple pleasures, y'know.  And maybe I can get him to run off some of his ya-yas.  As the trainer told us, "A tired dog is a good dog."

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This week's recommendation is a classic.

When I was a junior in college, I took a class called Seminar, which had a new focus/topic each semester.  That semester's course was a survey of the Book Gödel, Escher, Bach: An Eternal Golden Braid by Douglas Hofstadter.  Hofstadter does a masterful job of tying together three disparate realms -- number theory, the art of M. C. Escher, and the contrapuntal music of J. S. Bach.

It makes for a fascinating journey.  I'll warn you that the sections in the last third of the book that are about number theory and the work of mathematician Kurt Gödel get to be some rough going, and despite my pretty solid background in math, I found them a struggle to understand in places.  But the difficulties are well worth it.  Pick up a copy of what my classmates and I came to refer to lovingly as GEB, and fasten your seatbelt for a hell of a ride.

[If you purchase the book from Amazon using the image/link below, part of the proceeds goes to supporting Skeptophilia!]

Going to the dogs

I am the proud owner of two dogs, both rescues, who are at this point basically members of the family whose contributions to the household consist of barking at the UPS guy, sleeping most of the day, getting hair all over everything, and making sure that we get our money's worth out of the carpet steamer we bought five years ago.

First, there's Lena the Wonder-Hound:

And her comical sidekick, Grendel:

Both of them are sweet and affectionate and spoiled absolutely rotten.  Lena's ancestry is pretty clear -- she's 100% hound, probably mostly Blue-tick Coonhound, Redbone, and Beagle -- but Grendel's a bit of a mystery.  Besides his square face and coloration, other significant features are: (1) a curly tail; (2) a thick undercoat; and (3) a tendency to snore.  This last has made us wonder if he has some Pug or Bulldog in his background somewhere, but that's only speculation.

This all comes up because of a recent delightful study in one of my favorite fields, cladistics.  The idea of cladistics is to create a tree of descent for groups of species based on most recent common ancestry, as discerned from overlap in DNA sequences.  And a group of researchers -- Heidi G. Parker, Dayna L. Dreger, Maud Rimbault, Brian W. Davis, Alexandra B. Mullen, Gretchen Carpintero-Ramirez, and Elaine A. Ostrander of the Comparative Genomics Branch of the National Human Genome Research Institute -- have done this for 161 breeds of dog.

The authors write:

The cladogram of 161 breeds presented here represents the most diverse dataset of domestic dog breeds analyzed to date, displaying 23 well-supported clades of breeds representing breed types that existed before the advent of breed clubs and registries.  While the addition of more rare or niche breeds will produce a denser tree, the results here address many unanswered questions regarding the origins of breeds.  We show that many traits such as herding, coursing, and intimidating size, which are associated with specific canine occupations, have likely been developed more than once in different geographical locales during the history of modern dog.  These data also show that extensive haplotype sharing across clades is a likely indicator of recent admixture that took place in the time since the advent of breed registries, thus leading to the creation of most of the modern breeds.  However, the primary breed types were developed well before this time, indicating selection and segregation of dog populations in the absence of formal breed recognition.  Breed prototypes have been forming through selective pressures since ancient times depending on the job they were most required to perform.  A second round of hybridization and selection has been applied within the last 200 years to create the many unique combinations of traits that modern breeds display.  By combining genetic distance relationships with patterns of haplotype sharing, we can now elucidate the complex makeup of modern dogs breeds and guide the search for genetic variants important to canine breed development, morphology, behavior, and disease.

Which is pretty cool.  What I found most interesting about the cladogram (which you can see for yourself if you go to the link provided above) is that breeds that are often clustered together, and known by the same common name -- such as "terrier" -- aren't necessarily closely related.  This shouldn't be a surprise, of course; all you have to do is look at the relationships between birds called "buntings" or "sparrows" or "tanagers" to realize that common names tell you diddly-squat about actual genetic distance.  But it was still surprising to find that (for example) Bull Terriers and Staffordshire Terriers are more closely related to Bulldogs and Mastiffs than they are to (for example) Scottish Terriers; that Corgis are actually related to Greyhounds; and that Schnauzers, Pugs, Pomeranians, and Schipperkes are all on the same clade.  The outgroup (most distantly related branch) of the entire clade is the peculiar Basenji, a Central African breed with a strange, yodel-like bark, a curly tail, and pointed ears, whose image has been recorded almost unchanged all the way back to the time of the ancient Egyptians.

Anyhow, it's an elegant bit of research, and sure to be of interest to any other dog owners in the studio audience.  Me, I'm wondering where Grendel fits into the cladogram.  Considering his peculiar set of traits, he might have a branch all his own, and give the Basenji a run for its money as the oddest breed out there.