Who's a good boy, originally?
Updated: 4 days ago
If you type ‘who’s a good boy’ in Google and search, it shows you many adorable images of dogs of different shapes, colours, ages and sizes. The same goes for 'who's a good girl'. If you ever have petted a dog, there's a high chance that you provided social reinforcement by calling him or her 'good boy' or 'good girl'. It sounds more affectionate and intimate than the matter-of-fact praise of 'good dog!', given our natural tendency to anthropomorphize (to attribute human emotions, traits and characteristics to non-humans).
Whether you’re a dog lover who feels instant melting in your heart after looking at those infantile eyes eliciting a strong illusory response of human-like communication due to our evolutionary ‘unconscious preference’ or you like to strictly steer clear of those wagging tails and coats, almost all of us would admit that dogs do have very expressive eyes which play an instrumental role in our close bonding. Even though I personally find eyes of cows, goats, rabbits, horses, deer and other four-legged herbivores equally soulful, one can’t deny that dogs typically evoke our emotions the most as the first animal to be domesticated by humans.
But when I first saw in its natural habitat a whiskers-flaunting Pacific Harbor Seal, the carnivorous marine mammal with a fusiform body structure (rounded in the middle and tapered at both ends like a banana) rushing by quick succession of lightly lofted head on the air followed by submergence in Puget Sound, I didn’t expect that it would remind me of Thubi, my former canine companion. I even experienced similar emotional cues.
Were those dark deep eyes tricking my emotions with positive valence or was there some genuine merit in me finding similarities between seals and dogs?
Trembling ever so rapidly with icy-cold moisture of Pacific wind, I thought that apart from slight resemblance of skull structures, whiskered snouts, telling stares and inquisitive personality traits, there's seemingly not much to write home about in terms of closeness between the terrestrial member of the Canis genus (dogs, which draws association with wolf-like canids) and marine mammals of the pinniped group (seals, sea lions, walruses).
I started to read about them after returning to the hotel. A monophyletic group includes all descendants of that most common recent ancestor. Pinnipeds are divided into three monophyletic families: the Otariidae (fur seals and sea lions), the Odobenidae (walruses), and the Phocidae (true or earless seals) along with the extinct family Desmatophocidae. Harbor Seals belong to this third family of true seals and as the most widely distributed pinnipeds, they inhabit temperate and Arctic regions within the Northern Hemisphere in both the Atlantic and Pacific Oceans.
The word pinniped is derived from the Latin word pinna, which means “fin” or “flipper-footed”, something which has no congruence with Thubi's paws. Pinnipeds spend considerable time in water but also come to land to regulate body temperature, give birth, nurse the young, socialize and some of them also exhibit pagophilia (prefers ice for certain activities) like Ribbon Seals and Hooded Seals. There are some breeds of dogs who truly enjoy spending time in water, like Chesapeake Bay Retriever, Portuguese Water Dog, Newfoundland, Irish Water Spaniel, English Setter, Labrador Retriever, Schipperke, Poodle among few others. Thubi, a native Indian pariah dog, never quite liked water. But irrespective of this breed-specific preference, none of them needs to rely on a combination of aquatic and terrestrial habitats like seals.
Loose thought occupied my mind as I started to build on my instinctual perception. These were legitimate observations, but lame enough to not have any foundation. I started looking for similarities which could not be definitively falsified. For example, Californian Sea Lions make loud vocalization like dogs while establishing territories, but Harbor Seals are mostly quiet other than mating seasons when males produce underwater vocalization with a peak frequency of 1.2 kHz to attract females, comparable with frequency components of dog barking within 1 to 2 kHz. They also show in-air vocalizations like occasional short grunts and growls.
Seals have similar undulated vibrissae or whiskers like dogs through which they search for food trails. These act like antennas and they differ from normal hair as they are directed by the nervous system (innervated). Even if seals are denied with complete visual and auditory input (by making them blindfolded and putting headphones on them), studies suggest that they can still locate the prey fish with utter precision. Through the richness of nerves around their whiskers, they are able to relay information in their brain about the physical environment along with the direction and velocity of the prey. Just like them, dogs can find specific location and object without needing to be dependent on visual, olfactory and auditory cues. Whiskers serve as an incredible receptor providing tactile sensation and along with few other primitive path integration faculties, dogs can do such amazing acts even without strong eyesight. They can even pick up slight change in the air current due to this.
Dealing with the improbable
An eminent astronomer once said that if you disintegrate an airliner and jumble up their multiple parts, the likelihood of it getting assembled back again as a Boeing is vanishingly small. Similarly I found very small probabilities when I tried to create a seal in my mind with physical constituents of a dog. The anatomy is quite different after all. But then, what's the difference in me and a frog? Genetically, not much! Before we went our separate ways 360 million years ago, we had many things in common. Their nervous, skeletal and immune system develop quite similarly to us and hence scientists use them to understand humans at their simplest forms. And still it's impossible to trace back and correlate between me and frogs only based on visual cues. Hopefully!
Here I got much more to work with. But no matter how much I tried to correlate, I was standing on a shaky ground with scattered opportunistic logic. I thought evolution could be the only change-maker in this, if at all, as that can be the wild card to introduce such a great complexity by many orders of magnitude through a painstakingly slow cumulative process. I met with disappointment to start with.
While a visual field of 232° in the horizontal plane of a harbor seal can also be easily compared to 240° of a dog and the visual spatial resolution underwater for the semi-aquatic seals can be comparable with terrestrial carnivores, they neither belong to the same family, nor are they closely related. Nothing so far explains why on earth I would have an instant recollection of a dog's image at my first seal-sighting. Unsystematic observations often create illusory correlations. And then, may be I'm experiencing confirmation bias (i.e. once we got a hunch about something, we consciously and subconsciously try to find evidences that support that bias while ignoring equally compelling evidences that doesn't agree with the bias) and trying to connect the dots artificially, I told myself.
As I was pouring heated water from the drip coffee maker with partial attention towards the latest clicked article about harbor seals, I stumble upon its scientific name, Phoca vitulina. I shrugged.
What difference would it make had it been called Whothago othagis thothagat (the gibberish for 'Who is that?'), I murmured. Since Latin and Greek have historically been the international language of scholarly work in Biology, we don't get even an iota of hint about meanings of these scientific names of species. As if memorizing them while not understanding the meaning wasn't enough of a strain during school life, I frowned as I thought that my familiarity with the scientific name of dog Canis familiaris (“the familiar dog”), which has been revised as Canis lupus familiaris as they started to be identified as subspecies of wolves ("Canis lupus"), was enough.
Yet still I wondered with irritability, Phoca vitulina: what does it mean?
An article on Biogeogrpahy of Harbor Seals mentioned that Phoca vitulina, the scientific name for harbor seal, means “sea calf” or “sea dog.” An animated shiver ran through my spine as I read the line multiple times. The message is unmistakable.
Seal of approval
A giant California Gull swept across the pink crepe sky of Seattle waterfront when I approached a place near Pier 54 early next morning with the hope of spotting more harbor seals. Standing at this quiet spacious corner, amenable to observation, I mostly heard blind hissing of air as I waited patiently. Environmental conditions and seasonal factors influence individual seal's fidelity to a specific study area.
Finally I saw one on the near-shore coastal water. This one had a silver-white shade instead of brown. I noticed that the ear holes had no external ear flaps and the short forelimbs, which hinders their locomotion on the land. I chuckled as all these phenotypical distinctions blurred again with the thought of Moa, my Pomeranian.
I realized that I needed to dig deep into their evolutionary biology to find answers about what was no longer a piddling feeling, but clearly wrapped up in the scientific name. Further studies revealed that seals and dogs belong to the same taxonomical suborder Caniformia (literal meaning is "dog-like" carnivoran) under the order Carnivora (literal meaning is 'Flesh devourers' in Latin), a mammal family currently comprising of almost 286 species. Caniformia suborder includes Family Canidae (dogs, wolves, foxes, coyotes) along with Ursidae (bear, giant panda), Family Ailuridae (red panda), Mustelidae (badgers, weasels and sea otters), Mephitidae (skunks and stink badgers), Procyonidae (raccoons) , and guess who? Pinnipedia (sea lions, walruses and seals clade)!
Odd, huh? What they are doing in a list of terrestrial mammals? There are four groups of marine mammals other than pinnipeds: cetaceans (whales, dolphins, and porpoises), sea otters, sirenians (dugongs and manatees), and polar bears. And none of them feature in the list of Caniformia suborder apart from sea otters (Mustelidae) and polar bears (Ursidae). Polar bears are considered marine since they spend most of their lives on the sea ice-bed of Arctic ocean and depend on the ocean for food and habitat. But still they are semi-aquatic like seals. Sea otters, on the other hand, are fully aquatic.
Going back to the conundrum, how come they feature in this list? And when did they split with other families in the same suborder, say from Family Canidae?
Basically pinnipeds split from Caniformes (Any carnivore of the suborder Caniformia, which are regarded as dog-like) 50 million years ago and appeared in the ocean during Eocene age (geological time span 56 to 34 million years ago). That's why they are not related to other marine animals (whales, dolphins, and their kin) and fondly called as ocean pups. What I felt in split seconds without knowing any of these information was nothing but perhaps this original kinship with dog-like creatures. This felt subtly quite profound to find some real scientific support for what otherwise could have just been toying with a vague conjecture.
What group of terrestrial mammals then pinnipeds got most association with? This is a hugely debated topic. During the last 65.5 million years of our evolutionary journey, mice were transformed into men. There exists a major transformational gap between a terrestrial ancestor and the appearance of flippered pinnipeds. The complexity and organization of such a convoluted development from ordinary atoms to biological organisms in itself is one of the highly astonishing phenomena in nature.
Mostly based on morphological evidence, one hypothesis states that three pinniped families share a common origin in all likelihood with a terrestrial bear-like ancestor. Based on the molecular data, they are more closely related to weasels, otters and raccoons though. This established the possibility of cladogenesis, the evolutionary splitting into two separate carnivore lineages. The central idea, however, revolves around the fact that seals evolved from carnivorous ancestors that once walked on the land with stocky legs only to evolve later into flippers.
How is that possible? This has been the most difficult and dead-end question in the evolutionary research around pinnipeds.
The missing link of land-based ancestor got solved by the fossil evidence of a semi-aquatic carnivore Puijila darwini, a species discovered by Canadian paleobiologist Natalia Rybczynski in 2009 on Canada's Devon Island. A species which lived in the Arctic during the Miocene Age (23 to 5 million years ago), and has been already noted by Darwin much before without any of this evidence as "A strictly terrestrial animal, by occasionally hunting for food in shallow water, then in streams or lakes, might at last be converted into an animal so thoroughly aquatic as to brave the open ocean." This group evolved from land-dwelling carnivores with bears and the mustelids (otters, weasels, skunks and badgers) being the closest relative.
In the Eastern Canadian Inuktitut language, Puijila means young sea mammal, and darwini is of course to honour the memory of the British naturalist Charles Darwin who wrote about its possibility in his book 'On the Origin of Species', considered as the foundational book of evolutionary biology. This fossil offers insight on what early stage of pinniped evolution looked like and how it moved from land to freshwater before transitioning into a sea-dweller. Katherine Harmon in her article mentioned that "Although land animals are assumed to have initially evolved from sea-dwellers, some – such as the ancestors of whales, manatees and walruses – eventually crept back into the watery habitat, which makes these transitional species like Puijila an important glimpse into that evolutionary process".
Now that dogs have descended from wolves and sea-dogs (seals) have descended from a different mammalian carnivore like bears or badgers, who's the original good boy? Of course we can continue to drill down to some unicellular organism and then to the essential building block of all, DNA, which in turn is made of smaller nucleotides molecules, each made of...wait, my head has started spinning.
In the end, I think we did one thing very right, adding human-like attributes to non-human entities. I'm not advocating anthropomorphizing to a species' detriment, but everything gets enmeshed into a blur in the end, isn't it? Apart from the formidable and increasingly complex design, what's really different between me and a frog? The fact that my life can appear to have a meaning and I can attempt to find out who's the original good boy to feed human need for knowledge drawn with a moral compass?
Well, frogs are the reason for controlled insect population in the ecosystem and indirectly inside my home. Somewhere they unknowingly ensured that I could write this free from such disturbances. I think that's where the true meaning lies, when you don't know what purpose you are serving and yet you do that as a unique contributor to the grand design. Once we strive to know everything about our purpose, the magic of natural selection will feel the need of transitioning us to a different species and someone else will tell our likes while patting on their shoulders (if human remains safe enough to be alive), 'Who's a good boy, now?'!
PhotoStory Date: 27.6.2020
Place: Seattle and Bangalore
Words and Photograph: Amrita Ghosh
Resource Credit and Citations: Puijila, the walking seal – a beautiful transitional fossil , Nature article on the origin of Pinnipedia, Scientific American blog on missing link ancestor, Inverse article on Are Dogs related to Seals?, Michelle Wilson's article in the San Francisco State University website: The Biogeography of the Harbor Seal
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