The Best Australian Science Writing 2014 (26 page)

We might aspire to nobility in character and virtue in action. We can invest heavily in unselfish actions, such as fighting oppression or pollution or helping a club, a person, or an animal. When we take on a cause, we seem to become part of something bigger and from such endeavours may derive some of the deepest feeling of meaning. One of the most remarkable things about humans is that we can strive to make some kind of difference. We may deliberately practise random acts of kindness, spread the word, fight injustice, teach the next generation, or start a revolution. Without the urge to connect our minds, such traits could not exist.

In sum, nested scenario building and the drive to link our scenario-building minds turned ape qualities into human qualities. They created powerful feedback loops that dynamically changed much of the human condition. They carried us where other animals could not go.

Popular mechanics

The pet-keeping species

The pet-keeping species

Peter McAllister

Modern science has not been kind to
Homo sapiens sapiens
. One by one, each ability we had thought to be uniquely human – tool-making, problem-solving, language – has been found in species as far below us as the invertebrates. Even the humble octopus makes and uses tools. But there is one thing – a common human behaviour – that does distinguish us from the common herd: pet-keeping. Only we regularly live with, care for and even clean up the poop of animals we don't intend to eat.

Should we, then, admit defeat and re-classify ourselves as
Homo domestica bestia alitura
: the pet-keeping species?

It is a pretty weird claim to fame scientifically speaking, as it makes no evolutionary sense at all. Julius Caesar, centuries before Darwin, was the first to notice this. Why, he asked tartly, didn't the foreign noblewomen he saw cooing over pet puppies and monkeys save their titbits and affections for the recipients nature intended – their children?

Darwin didn't directly address the evolutionary puzzle of pet-keeping, but he did wrestle unsuccessfully with the problem of altruism. Why, he wondered, would organisms engaged in the ruthless struggle for existence spare precious resources to help unrelated others?

Not even kin or group selection theories can help here: your Bichon Frise fur baby might share your bed, your food, your walks and your car rides, but he or she definitely doesn't share your selfish genes. So where could this emotional connection with animals come from? If the evidence of modern hunter-gatherers is anything to go by, it was there already with our hominin ancestors, although it appears it hindered, rather than helped, their hunting lifestyle. Present-day tribal hunters sometimes feel so guilty about their murderous assaults on prey animals that they perform elaborate rituals of apology to them – rituals such as those of the Sumatran Mentawai who stroke the prey's corpse with flowers to ask its forgiveness.

And you felt guilty about not buying that KrazyKitty playwheel!

* * * * *

The fact that human pet-keeping so stubbornly defies evolutionary explanation means we often fall back on potential cultural answers instead. Human pet-keeping is, we theorise, a quirk of aristocratic elites that only went mainstream when we all became rich enough, and bored enough, to maintain mini-menageries, suburban Raja style. And some evidence does support this. Pet numbers over the past 50 years, in the Western world at least, have grown so quickly in tandem with our rising affluence that our furry friends now outnumber their owners in some Western countries. And history is indeed littered with kings, nobles and other potentates who used their wealth to support bewildering menageries. The late 17th-century Shogun Tsunayoshi, for example, made his city of Edo stink by keeping 100 000 dogs there. The Chinese king of Chu, 2000 years earlier, cut down an entire forest to find his missing pet gibbon. At least one Roman matron kept a genuine gold fish – a live turbot decked from head
to tail in gold jewellery – and even the primmest of American presidents, Calvin Coolidge, packed the White House with geese, donkeys, wild bobcats and pet raccoons that his wife, Grace, took for walks on the White House lawn.

Yet the very fact that the super-wealthy are so often first to open their homes and hearts to fluffy, furry visitors, and that we plebs follow suit when we can afford to, may actually prove the opposite – that pet-keeping is no upper-class foible, but instead a universal, instinctual human behaviour erupting whenever constraints (in this case economic ones) are lifted.

The evidence of modern hunter-gatherers is again suggestive. Explorers' accounts show most tribal peoples did keep pets when they could, sometimes in numbers rivalling those of the most decadent European menageries. The native peoples of Ecuador, for example, treasured everything from birds, lizards, possums and monkeys to sloths, coatimundis and ocelots. Some North American native peoples' tastes were even more exotic, stretching to moose, bison and bear cubs, which their women breastfed. Not to be outdone, native men also coddled their pets – anthropologist EB Basso, for example, wrote that Brazilian Kalapalo men chewed their pet parrots' food for them, and Carl Lumholtz reported that Queensland Aboriginal men not only kissed their pet dingoes but also picked and ate their fleas.

True, it is possible that these shared pet addictions, although practically universal, were culturally driven. But how then to explain Geronimo's pet cat? The elderly Apache warrior adopted and doted on a tabby while imprisoned by the US government at Fort Sill. Yet Geronimo was born into a culture famous for encouraging its children to torture animals. What could have softened the grizzled old fighter's heart if not an instinctual human propensity to love pets, released when those cultural constraints were lifted?

If there is a universal human instinct to love pets, however,
it must have arisen early in our evolution, certainly before our dispersal from Africa. What evidence is there that it did? DNA analysis using molecular clocks is not much help, giving dates that vary from 100 000 to 24 000 years before the present. The archaeological record, too, is unfortunately of little help.

I'm going out on a limb here, however, to say that I think there were such pets. Here's why.

The intuition first hit me while trudging up a small sand dune in the broiling heat of the Pilbara desert. I'd been walking all day with a Mardu elder man, Djalego, looking for Aboriginal archaeology. We came across a dingo mother's den instead, dug into the sand in a tangle of mulga roots.

‘Tingku [dingo] bitch move 'em pups last night time,' Djalego announced, surveying the tracks at the den mouth. He flashed me a wide grin. ‘Lucky for her – I take 'em back for kids if I find 'em.' He would, I knew, have been as good as his word. Djalego's community at Jigalong is thronged with mobs of halfloved, half-feral mutts ranging from chihuahua to dingo and anything in between. Tribal peoples everywhere have always had such encounters – British explorer Samuel Hearne, for example, reported in the 18th century that Inuit hunters would often dig into wolf burrows simply to play with the cubs, sometimes even painting their faces with ochre and vermillion, before either returning them or taking them back to camp.

That's when it struck me – possibly because the Australian desert is so reminiscent of African savannah, with its tawny spinifex standing in for grasses and gnarled mulga for acacia scrub – that this scene must have played out tens of thousands of times in our ancestors' two million or so years on the African savannah. We know
Homo ergaster
and
erectus
ranged roughly as far as modern hunter-gatherers, and that their similar growth trajectories mean they would have had ‘kids at home' too. Why, then, wouldn't they have raided the occasional
Lycaon sekowei
den (the Pleistocene ancestor of the African Painted Wild Dog) and taken a cute and cuddly little piebald bundle back home for their own
erectus
tots? To say nothing of warthog piglets, sabretooth kittens, impala kids, or any of the multitude of potential pets out there on the African savannah.

One thing bothered me, however. Although Djalego had said the pups would be pets, were they perhaps really slated for another role – hunting? Dingoes are commonly assumed to be great aids to Aboriginal hunters; many proponents of the ‘animal connection' hypothesis believe wolves co-evolved with early hominins in the same role. Might Djalego have been actually intending to use the dingo pups for tracking prey with his kids' fun being just a side benefit? He quickly disabused me of the notion. ‘Tingku bark too much, scare off that malu [kangaroo],' he said, miming a hunter missing his rifle shot.

Anthropologists' accounts show his experience is universal. Hunts using dingos invariably end in farce, the dog tearing disobediently off out of sight to the tune of shouted curses from the hunters, only to emerge from the scrub hours later with a bloody muzzle to show it has hunted and eaten well, even if its owner hasn't. Even the lovable, lolling half-breeds of Jigalong and other communities are useless: the only dogs Aboriginal people have ever successfully hunted with were purpose-bred domestic breeds, like the famous ‘kangaroo dogs', bred from British deerhounds and greyhounds, used in colonial-era Tasmania.

This is also, incidentally, why the co-evolution hypothesis of wolf/human hunting collaboration is almost certainly wrong. For wolves are even wilder than the dingo. Given that no hunter-gatherer group in history has ever been found to use wolves or any other wild canid for hunting, it seems unlikely that
Homo habilis
,
ergaster
or
erectus
did either – even for the scavenging that may have been their main subsistence.

If they did pick up kits, pups, piglets or other assorted
adorables, out there on the savannah, they did it for the same reason Djalego did: love.

* * * * *

The love of pets might indeed, to paraphrase Anatole France, have awakened the
Homo erectus
soul, but how, again, could we know it was there if it doesn't show up in the archaeological record?

There is one way: by looking for analogues in animals close to our ancestors. We may be the pet-keeping species but there are intriguing hints that chimps and bonobos would join us in the cross-species affection club if they could. Two Swiss researchers in Tai National Park, Ivory Coast, saw four young chimps playing with an intensely alarmed young duiker, trying to give it piggyback rides – just like an infant chimp. And primatologists in the central region of the Democratic Republic of the Congo saw even more elaborate behaviour.

In one four-week period, they saw two male bonobos in three separate incidents playing with infant monkeys of two unrelated species – the Angolan colobus and the red-tailed monkey. Again, the apes tried to piggyback their unwilling playmates, just like young bonobos, and when they didn't cooperate, they groomed them. In other words they petted them.

Unfortunately, chimps and bonobos are far too wild and violent for this cross-species pet play to ever succeed: most of these proto-pets died from their ‘games' within the hour. Yet the apes clearly find their unfortunate playmates ‘cute' in just the same way we do our pets. Their behaviour is also obviously, in intent at least, a primitive attempt at pet-keeping. It is affectionate, playful, and aimed at keeping the ‘pet' with its ape ‘owner'. But what motivates it? The clue lies in the chimps' pseudo-parenting behaviours. They groomed their animal charges as if they were
real ape babies, played with them like babies, and even tried to make them piggyback ride like real baby chimps and bonobos.

The cuteness that makes a chimp or bonobo pick up and cherish (or attempt to, despite their klutzy violence) a non-related animal pet is apparently that pet's ability to trigger parenting behaviours in its ape ‘owner'. This is clearly unwelcome and no evolutionary advantage at all to an Angolan colobus or duiker infant. It will, in fact, probably eliminate it from the gene pool in minutes. But what if a pet animal was able to make an owner pick it up who could carry it gently away, who would feed it titbits, and who would keep it warm (when it invented fire), and dress its fur with custom kitty-comb grooming gloves in front of the TV (when it invented those) too?

The fact that our pets make us love them by hijacking our parent/infant bond will be no shock to most proud fur-baby owners. It is to any self-respecting Darwinian theorist, however. Why hasn't natural selection weeded out this surprising, anti-evolutionary vulnerability?

There is one possible answer from zoology. Konrad Lorenz wrote extensively about fixed action patterns (FAPs), instinctive behaviours in animal parents automatically triggered by actions of their young that Lorenz called releasers. Adult African painted dogs, for example, involuntarily regurgitate food (the FAP) when their pups lick their muzzles (the releaser). A newborn kitten's first poop, similarly, prompts its mother to eat it (the faeces, that is, not the kitten). Some FAP releasers, however, are shared across species. One of the most important, according to Lorenz, is the suite of physical characteristics common to most mammal infants – large eyes, broad and vertically squashed faces, and reduced nose and jaw size. Lorenz called this set of releasers the baby schema. One glance from those impossibly big-eyed cuties, he said, was enough to ignite hormonally driven parenting FAPs in mammals as diverse as marmots and musk oxen.