Nothing like Turkey on, well, Turkey Day. Drumsticks, creamy breasts, and crispy turkey skin, yum-yum! Not to mention the turkey sandwiches and turkey dressing and turkey gravy. If they had such a thing as turkey bread or turkey Ice Cream, I'd probably eat that too.
Now we all recognize the turkey as a bird, I dearly hope anyway creationists perhaps excepted, and many of us now recognize the turkey as a derivative of the raptorial dinosaurs. But how many of us would recognize the humble turkey as a holocaust and chemical weapons survivor? A high altitude explorer? Not many I bet, and yet, it may be true.
Join me on a voyage in time, in mind only; think of it as Science-Faction. Lets go back, over a quarter of a billion years, when the ancestors of Tom Turkey may have first distinguished themselves, not with brain or brawn, but with their wind, and came of evolutionary age in an environment that may seem surprising.
Above: The Earth as it may have appeared from space, 280 MYA: The single continent of Pangaea occupies the entire eastern hemisphere. Below: The lush swampy environment of a Pangaean forest
Two-hundred and eighty millions years ago: The planet earth is dominated by a single continent that stretches from pole to pole. This is Pangaea. The giant landmass is shaped like a thick letter "C", cradling a shallow inland sea to the east with its western back to a global ocean. All of earth is brimming with life, some strange, some familiar, and some downright nightmarish! In the broad terrestrial jungle paradises there are as yet no flowers, and the first grass is a cool quarter billion years in the future. But the coastal plains, massive swamps, and lush river valleys are bursting with brilliant green ferns and conifers accompanied by horsetails the size of oak trees, all drenched in lichens and mosses, all dripping with moisture. The seas are full of fish, arthropods large and small, and giant squid-like nautiloids chomping at the bit for any scrap of meat. Had you a fishing pole and some bait, you would have been kept in sushi forever.
Paradise is of course relative, and here and there are signs that this world is fundamentally different from the one we know today: If you could see one of the larger land vertebrates, say the friendly sail-back Dimetrodon, you might notice that they seem to be barely breathing, and nowhere is there a dead dry twig or a desiccated brown frond. Trees with bark had only barely begun to evolve. The undergrowth forms the familiar tangle of quickening brush and decaying vegetable matter, but it is a dark greenish-black in these steaming primeval rain forests. The bugs and worms are everywhere just like today, but they belong to the most monstrous array of arthropods to ever exist: There are dragon flies with wingspans three-feet across, cockroaches the size of footballs, centipedes four feet long, and spiders with bodies as big as a man's head.
Should you be startled upon seeing one these super-sized scuttling critters a little too close for comfort, don't hyperventilate! The resulting headrush might be so intense, you could wake up on the ground, which would be a bad idea here and now. Just a few seconds of lying incapacitated and God only knows what might be eyeballing you through multiple compound cameras wondering if it's safe to move in and start chewing you up, with mechanical mouthparts whirring like a little garbage disposal. Yes, this world is very different on closer look, the similarities to the one we're used to are deceiving. The difference isn't limited to animals, sea monsters, or plants, it is literally in the air.
You might notice your skin blisters in five minutes in the harsh tropical sun, or you might taste a burning sensation in your nose and throat. And should you light a match, you might suspect what's going on, watching that flame flash like a silent firecracker and burn the matchstick to your fingertips in a fraction of a second; as though it were a gunpowder fuse.
It's the oxygen content; Here, it's almost twice as high as what your body is used to and the spectre of oxygen narcosis and greatly accelerated chemical degeneration by oxidation is a real threat to our survival. Breath in shallow draughts and we'll be OK.
This is the end of Carboniferous, so named because of large deposits of carbonized plant material date to this era. That's probably not a coincidence: In the presence of 35% oxygen, fallen plants and just about everything else would slowly burn in situ, turning carbon black, long before they rotted away, leaving a vestige we call coal. It's interesting that the initial power for our own industrial revolution would start so long ago, from the loins of an ancient swampy landscape that will soon be undergoing its own radical revolutionary change.
But the rotting vegetation lasts long enough to make good nest for the new leathery eggs which have only recently evolved to withstand dry land. Amniotes have arrived, the first full blown reptiles, archosaurs, lizard like mostly. They've barely evolved past amphibians, now already on the move along the evolutionary ladder to crocs and turtles. But we're here to look for something else, and we're probably not going to find it in the lowlands.
Small archosaurian lizards faced stiff competition from giant arthropods and amphibians. This little guy will head for the hills to make a new life and become a new kind of reptile
If you're a smallish lizard-like archosaur, it might be pretty tough competing with giant spiders, scorpions a meter long, or carnivorous amphibians with a taste for lizard meat. You might have better luck following the streams into the landlocked frontiers, along into the interiors, or better yet, the higher elevations where the oxygen level and ambient temperature is too low to support giant insects and their cousins.
So perhaps we need to go up in altitude and forward in time: Far up the flanks of the tallest Pangeaen Mountains that stitch the tectonic plates in a network of sinuous ridge-lines into one giant landmass marking the backbone of earth's single great continent. So let's leap forward a few million years to the Permian of 260 MYA and start hiking up the slopes. That might our best shot to find Tom Turkey's great to the Nth grandma.
A ways up the taller peaks, a mile above sea level and a hundred miles inland, we spy curious animals: Most the size of a wolf, they have bizarre teeth, some feature tusk-like projections to root around in the moist mountain soil between ancient, pine-like plants, for grubs and roots. These are the newest therapsids: Mammal-like reptiles. Soon they will rule the world although that rule will be short-lived. But again, as interesting as they are, they're not what we're looking for.
Lystrosaurus; These therapsid critters diversified greatly during the Permian, about 270 MYA, occupying niches similar to the pigs, badgers, and antelope, of today
Gorgonopsians: One of the top therapsid predators of Permian time, likely an arch-enemy of the lystrosaurus and just about everything else. These creatures were the great cats or wolves of their day. They may look alien, but the different kinds of teeth readily apparent identify them as closely related to the ancestors of all modern mammals
Higher still, we rest at the 15,000 foot line, on small plains paradoxically wet with jungle steam; a rare combination of humidity and altitude found today only in the Andean Plateaus of South America. Here the partial pressure of oxygen falls below our own modern concentrations. Here among a few struggling conifers threaded with clear water streams, hardy alpine ferns, and rocky outcrops carpeted in thick lichens and moss, not nearly so many animals are found. In these pocket sized ecologies, laboratories of evolution, there's only an early insect here, a tiny lizard there; not much to eat, nothing like the rich living tapestry now far below. Anything that calls this home had better be smart, resourceful, and able to eat a wide range of food items. And it sure better have efficient lungs if its going to chase dinner down.
Streaker: Turkey ancestor?
Finally we see them, lets call them 'streakers', because they streak like roadrunners from cover to cover, sometimes on four legs, sometimes on two, so fast you can't clearly make them out. They're small, barely a foot long including the tail, half the size of a chicken, and they're lightly built. They're sort of like quasi-bipedal lizards, very similar to that ancestor that took the hills millions of years before but with a few changes. It's hard to believe these humble little creatures represent a quantum leap in evolution. Most of the innovations are on the inside.
They're smart, much smarter per pound than most therapsids. They can withstand extremes of heat and cold; If you picked one up when it's active, the first thing you'd notice is that they're slightly warm. And that's the first new trick: Streakers can rest like a reptile but run like a gazelle; if need be they can shut down entirely and go into a kind of suspended animation. Where canids today can freeze in ambush for a few minutes and the great cats can stay still for hours, these little guys can sit as motionless as a rock for days if need be burning next to no fuel. But they can also shift their entire metabolism into high gear in just a few seconds and operate like a mammal, when an opportune bug or small lizard ambles by. That's quite a useful range!
Examining their skeletons reveals even more intricate adaptations. Streaker bones are incredibly lightweight and filled with thousands of little air bladders. The skull and limb bones in particular are almost paper thin, hollow tubes, riddled with arching cusps and fine, swirling bony struts. It's as if the framework is high-grade, spun fiberglass, giving the most strength for the buck imaginable. Strangely, the lungs are tiny ...
It takes some time to figure it out, you have to watch the lungs in operation for it to make sense. When these creatures breath in, one set of the bony hollows, those in the lower half of the body, fill up. When they exhale, the other set of bony compartments, forward of the lungs expunge the air, the lungs barely change in volume ... what's going on?
The lungs are not bags which inflate and deflate like ours, they're just flexible vessels. The air from the back set of bony compartments flows over the lungs on each exhalation, while the air form the forward set flows over the lung surfaces during inhalation. The lungs themselves never exhale. With each breath in the lungs are charged with oxygen, and with each breath out ... the lungs are charged with oxygen! That's why these guys can zip around in fifth gear while everything around them is either sluggish or limited to short sprints. Now that is one hell of an advantage in this high altitude, oxygen poor environment!
Lastly, if we could find their tiny nest, we'd see a little circle of sticks and leaves, with a couple of small leathery eggs inside. Watch them hatch, and you see the young are covered in hair-like downy filaments to help keep them from freezing in the cool mountain nights. These are the first creatures of their kind on earth. We don't even have a name for them, there are no fossils of these little guys. They're too new, too thinly distributed, too small, too frail. If not for our Thanksgiving Time Machine, or their descendants, we'd never know they existed. Their world is fixing to change, radically.
Far to the east, deep beneath the lurid green jungles and steamy swamps, the future of every creature on earth is being unilaterally decided by the most cruel of geological forces. The great continent of Pangea is about to be torn apart, a series of giant hot plumes are welling up beneath the crust, and slowly melting everything in theirs vertical path. Soon the resulting fissures will stretch hundreds of miles throwing curtains of lava skyward along the northeastern horizon. An area the size of the state of Texas will turn into bubbling lava. The release of methane and carbon dioxide will heat directly, following up with greenhouse entrapment, drying this wet world, until the great fern jungles whither and die. The cataclysms will rip the single land mass into fragments, throwing them in geological slow motion all over the earth's surface. Over ninety percent of every living Permian species will die.
In a few hundred thousand years the warmth will work into the furthest reaches of the great global ocean. The mighty global currents which took hundreds of millions of years to form will break down completely, the oceanic heat will be trapped near the tropics and work to the bottom. Huge stores of methane hydrate on the seabed will convert to gas, in some places the ocean will bubble like a hot tub as greenhouse gases boil into the atmosphere by the megaton, raising the temperature further. In one-million years the average temp will rise 15 degrees Fahrenheit, the great algal blooms of oxygen producing bacteria will die, the air will turn poisonous and heavy: Earth will plunge into an anorexic gaseous bath. The oxygen content will be cut by more than a half. Little from the great Permian and Carboniferous ecosystem will survive the roller coaster ride of hot and cold, suffocation and drought. The new Triassic Sun will beat down on a parched dry earth where vast deserts replace the proud rainforests of the past. A narrow band of vestigial green hugging the shores of sea and river will be all that's left of the lush steamy jungles.
But the little streakers from 15,000 feet up will thrive. High above the heavier atmospheric toxins, safely out of reach of the worst heat, they will proposer as much the food chain is driven into their strongholds to escape the heat of lower elevations. Their descendants, outfitted with the special lungs, the sleek pneumatic bones, the omnivorous diet, and the bipedal speed, will move further and further down the mountain sides into the recently vacated econiches of the giant bugs and the slower moving reptiles. They will spread across the expanding deserts along the creek bottoms form coast to coast, splitting again and again into new clades.
Argentinasaurus, dwarfs the whales and its sauropod cousins, weighing in at close to 100 tons
Over the next one-hundred million years, they will grow larger, first to the size of coyotes, then bigger than the largest prize winning hog, they will surpass the elephant, some will outgrow the great whales. They will thunder across the world with gnashing teeth the size of swords, they will rule the planet encased in armor like tanks. they will flash spines gouged with blood, sprout spikes and clubs, learn to cooperate in packs. Their hairy filaments will evolve into primitive feathers, and some of these new creatures, sporting quills now drenched in brilliant color, will even take to the skies to soar into our own time.
The dino family tree Enlarge
The Streakers will become the dinosaurs, and finally, the birds. And one of them will conquer the sky, evolve into a walking ave, be semi-domesticaed by American Indians, and become the feature feast in a North American tradition marking the birth of our nation: The Meleagris AKA Tom Turkey. And every one of them carries those ancient mountain lungs that evolved so long ago, in a now vanished Permian plateau.
So, when you tear into him or her this Thanksgiving, have some respect for the amazing journey that Tom's ancestors took. And always remember: If not for a quirk of evolution, a stray cosmic ray, or a shift in a long vanished faultline, the tables might very well be reversed. And in your place would be a family of dinosaurian ovanoids, sitting happily at the table, with a small primate, cooked to a golden crispy perfection with a tuber in his mouth, and the chicklings arguing about who gets the brains.
Illustration by Brent Rasmussen